Tandem Cycling - Full Suspension recommendations or feedback

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tandemonium
09-22-05, 07:28 AM
We are now considering a fs tandem for 2006. I've observed postings pertaining to reliability issues with the rear linkage of some name brand machines. Our team weighs 400 lbs. What are you using and how has the manufacturer's long term product support been?


TandemGeek
09-22-05, 09:29 AM
Your domestic choices are:

1 - Ventana El Conquistador (we're on our 2nd; it's the benchmark for F/S tandems)
2 - Ellsworth Witness. It's only made in one size
3 - daVinci Symbiosis. About $7,500 with independent coasting. Few few made but coveted by those who own them.
4 - Boulder Bikes. I've seen them and they look OK, but not as robust as Ventana.
5 - Chumba Wumba. Custom downhill
6 - Santana Dual Moto. Now made out of IsoGrid frame; got $12k?
7 - Older Santana Dual Motos. Rear suspension parts are hard to come by.
8 - GT. Very few made, but not a bad design if you can find one that fits.
9 - Chuck's Bikes F/S model. May be OK for light duty, but no thanks.

There have been some other efforts by KHS and several European manufacturers but, at the end of the day, the Ventana -- which is still not perfect -- always seems to rise to the top of the list. Great support and a solid product for a reasonable price.

Drop a note to Alex Nutt at MTBTandems.com: alex@MTBTandems.com for more information and to chat about off-road tandems. He remains, to the best of my knowledge, the only off-road tandem speciality dealer in the US.

tandemonium
09-27-05, 08:10 PM
I've been digging through mtbtandems website lately. I am surprised at how few tandem riders venture off road. Thanks for the detailed info.


Brian
09-28-05, 07:57 PM
We take ours off road, but the weather has not cooperated much lately. Now that it's spring time, I expect that we'll have more play time, and less coffee shop runs.

ricardo kuhn
09-28-05, 09:39 PM
Personally I ride My Ibis in the dirt every time i can, but i preffer to run a Full Rigid set up with really strong rims, wheels and really big tyres(2.8" in front).

http://patineto.smugmug.com/photos/33121788-M.jpg

since i'm not really convince full suspension Tandem technology is there so far and for sure running just a suspension fork is not to efficient do to the rear wards pivot location,A.K.A. Rear wheel, the issues with Full suspension are not even in terms of weight, price, longevity or reliability but the basic performance since you always have a big compromise for example you have two option for the bottom brackets ...Way to high (15"/16"inches high) or lower but then you are hitting rocks and berms and things all the time with the pedals even if you are running 165MM cranks and also the timing chain.... plus the bike bounces up and down (fore and aft i guess) under braking and among rocks gardens and jumps, plus gives you no feedback or at least very little ..

I'm sure suspension tandems are fine for "SUV Posser Comfort types" but when is time to really Go For it and get on a rocky singletrack they become like "walking on a water bed" or so sprung on the forks and shock the suspension varelly move but you still have to deal with the extra complexity and Inerent flexion.

Yes.... Over the year I test a bunch of diferent ones, from the Interbike demo's to Super fancy bikes I build at the shops i work before or the people I find on the trail.

again this is a very personal opinion, plus I really enjoy the challenge of picking the perfect line and the Raw feel the contact with the ground gives you.

Brian
09-28-05, 10:02 PM
Alex at MTBTandems has a photo of him and his wife airborne on their website. I think that's on their Ventana, which is a full suspension, if I recall correctly. We've got a 5 inch fork up front, and it does a really good job. I don't think you can compare a tandem FS to a single FS. I certainly wouldn't mind a full suspension frame with the daVinci independent pedalling, a Rohloff hub, and a titanium frame with S&S couplers.

tandemonium
09-30-05, 06:38 AM
I've been having issues with our rigid tandem beating my wrists on rooted trails and rock gardens. Also, a bit of compression from the front fork would really help when powering out of ruts since you can't unweight the front upon instinct.

I agree with Ricardo about the clearance issues as they have become quite apparent already.

We had a pleasant surprise last week when we crushed a climb up a rooted hill that I wasn't sure we'd make. The lack of front suspension was not as much of an issue on that climb as I suspected.

How about some additional info?
What tires are you running and at what pressure?
Expatriate (or others) what front shock are you using?

ricardo kuhn
09-30-05, 09:34 AM
I've been having issues with our rigid tandem beating my wrists on rooted trails and rock gardens.

Tandemonium I'm right there with you, maybe that is why I'm getting one of the last JPMorgen stems ever made trying to mitigate the "SuperJolts"
http://patineto.smugmug.com/photos/38092190-M.jpg

Nice and very strong paralelogram design ussing a hydrolic piston, yes they were design before softride came with their own, but JP is not the lawyer type and did not do any patents so they got the advantage.
http://patineto.smugmug.com/photos/38092194-M.jpg

this is not my bike, but you get the idea
http://patineto.smugmug.com/photos/38092193-M.jpg


Also, a bit of compression from the front fork would really help when powering out of ruts since you can't unweight the front upon instinct.
I also agreee with you on this ...

what I'm trying to say is "Convensional" telescopic designs are not that way, since they relay on the angle of attach of the wheel to become active.

maybe a A-arm type design like on my Golem bike (kind of handmade mega dirtbike) will work far better since the sistem provide a "Antidive feature under braking and the bike does not act like a pogostick..
but then you will need to make a frame base on this design since it can not be retrofit to a convensional frame.
http://patineto.smugmug.com/photos/212710-M-1.jpg

maybe a "Old school" Leading Link concept, since the axle path basculate as oppose to compress, making the forks a lot more tunable and for sure active.
this is my friend's Scott's Paris dakar racing sidecar, pretty much the most sofisticated and the fastest dirt bike sidecar ever made .
http://patineto.smugmug.com/photos/1505300-M.jpg

actually a fork was made for some time a few years back by one of the geniuses of the motorcycle and bicycle Industry, the name Mert lawill, sadlly i can not find any pictures, I have one of the 13 originals until i destroy it, since I let everybody try to go up steps with out lifting the front end and eventually the headtube broke off.
this Fork is Incredible in terms of the travel capavilities and i believe the perfect option for a tandem since is super active but the shock reaction can be tune and run at really sprung rates with out making it to harsh or bouncy.

again sometimes Is kind of funny to see how people just put "A fork" that does not belong (is not apropiate for the geometry of the machine) and just because is a brand name they assume is going to work just fine..




I agree with Ricardo about the clearance issues as they have become quite apparent already.

That I have No idea how to fix specially since I believe in full leg extension, actually I use the Old "Hiterite" spring so the seats can be drop really fast for downhill but then again that one works when you are not pedaling.
actually a few years back the long gone Ibis company ( the brand is coming back to business) was working on a shaft driven tandem tranny so no timing chainring will be necesary, but that only fix the chainring, not the pedal & crank issue, sincerlly i don't know the answer.... well that makes it even more fun.




We had a pleasant surprise last week when we crushed a climb up a rooted hill that I wasn't sure we'd make. The lack of front suspension was not as much of an issue on that climb as I suspected.

I ear you laud and clear...
I hate when you are almost pass the obstacle and then the whole bike moves backwards very violentlly, well same as a single bike but at least with the tandem you have more momentum, I find out the extremlly big tyres help a lot since the deform to the shape of the obstacle and kind of roll over.
for that same reason i'm looking for a really REALLY strong 29ER rim following the theory that a bigger diameter tyre is more prone to roll above things..
will see so far the rims are a little weak, but they are getting strong day by day the more popular 29Er bikes become..


How about some additional info?
What tires are you running and at what pressure?
Expatriate (or others) what front shock are you using?

Who Me...???
I run the Biggest freaking tyres I can find, so far i try a 3inch one but was a little to flexible and extremlly heavy so i'm running 2.8' with great luck,
not much regard for rotating mass (they are so so heavy),,,pressure,,,high...!!
as much as I can cramp in them, i will say about 60/65psi since the casing of the tyre is so high you can run a high pressure and you still have cushion, also snakebittes are a pain to fix, i do use michelin downhill tubes that provide exelent punture resistance but they are not infalible to any extend
http://patineto.smugmug.com/photos/33121694-M-1.jpg

I hope this helps , I'm being around Forks and suspension for far to long and maybe i'm getting to picky about them...

well i will show you progress when it happends.

stapfam
09-30-05, 04:10 PM
I've been having issues with our rigid tandem beating my wrists on rooted trails and rock gardens. Also, a bit of compression from the front fork would really help when powering out of ruts since you can't unweight the front upon instinct.

I agree with Ricardo about the clearance issues as they have become quite apparent already.

We had a pleasant surprise last week when we crushed a climb up a rooted hill that I wasn't sure we'd make. The lack of front suspension was not as much of an issue on that climb as I suspected.

How about some additional info?
What tires are you running and at what pressure?
Expatriate (or others) what front shock are you using?

My type of offroading may not be as aggressive as a full SOLO downhiller may give a bike, but that Dale MT does go through some punishment. I come from solo XC grounding and the tandem has been set up to ride our hills in the south of England. Very steep hills, plenty of ruts, roots and scree, and all based on chalk that is like Ice when wet, and like custard powder when dry. Brakes are Hope Mono M4's, wheels are Hope Bigun hubs on Mavic Downhill rims, front suspension is rockshox Boxer with a few mods to make them a bit more suitable for Tandems, and Stokers suspension is courtesy of a 3" Thudbuster.

Clearance is a problem and little paint is left on the undertube, but as yet no dents. Climbing is not a problem, and I cannot remember the last time we had to walk a hill.(Yes I can- jan 2004 up a 15% scree covered hill that lasted just a bit too long- and we gave up after 1.25 miles of the 1.5 it lasted) Downhills are taken at speed and we have every confidence in the Panaracer 2.1 Fire XC tyres at 60 PSI. We have tried larger tyres, but they skate across slippy parts of the track wheras this 2.1 size bites through the gloop to give us traction and has the additional bonus of not collecting mud between the tyre and frame, so not giving us "Extra" drag in those days when you really should not be riding any form of bike.

Any experienced offroad tandem rider will look at our spec and criticise it, but this all works for us. To date the Boxers are fantastic, but we also have 20 mm front axle that may help on the stolidity of these forks. We do bottom out on the 6" travel, but not with a clunk. Only problem these forks cause us is when out of the saddle, as they can bounce a bit if too much aggression goes in, but we no longer do that. Besides, this bike is set up for the offroad aggressive riding that we give it. Not only are the downhills taken at speed, rabbit holes at 30mph on the flat or the odd football sized Flint that suddenly appears in the track do not bother this bike either. The bonus is that with the Thudbuster, the Stoker does not realise how rough the track is at all, so the pilot can concentrate on his job instead of worrying about the stoker's backside.

Now about the A Arm suspension forks on Cycles. They used to be about, and were a very effective fork. Why they stop being used I think was mainly down to weight and looks. Price probably came into it aswell, but they were not any more effective that the then current suspension fork. The suspension stems have been about for years, and I used one several years ago. It was most disconcerting to hit a bump on fast downhills, and suddenly find your hands suddenly 2" lower. Similarly on technical uphills, when you wanted to lift the front end over an obstacle, you would try to lift the front end and all you did was raise the stem ,without lifting the wheel. Not a good idea for aggressive riding or tricky trails.

Off road riding is a compromise. On my solo I would go for a lightweight Stiff frame and rigid forks. This would give me the edge uphills and I know I could look after the "Fragile" bike when it gets technical. On an off road Tandem, Lightweight does not come into it. Front suspension is a necessity if any fast riding is involved. Disadvantage for climbing, but necessary elsewhere. Good brakes are a must, and the quality and strength of the wheels has to high to cater for the "NO-Brain" pilots whenever Gravity takes over. On those ruts by the way, Tandems do not like them, but suspension does not help you when trying to get out of them either.

Brian
09-30-05, 04:16 PM
[snip]
How about some additional info?
What tires are you running and at what pressure?
Expatriate (or others) what front shock are you using?

We're currently running some Continental 2.1 XC tires, because we have a stack of them. A bit skinny for the bush, and a bit wasteful for the roads. We went with the T5 from ATC Racing for our fork. While I will swap to a Marzocchi DJ at some point, when we want to travel, I chose this fork for several reasons. First, it's totally user serviceable. Changing springs or oil is a piece of cake, and can be done by any competent home mechanic. The guy that builds them has a shop down the street from my brother in California, so it's easier to get parts for it than it would be for anything I would buy here in Australia. Go figure. Second, it's easy to change the configuration. We have a 20mm thru-axle, and 8 inch brakes. If we wanted to swap to a standard 9mm QR and 6 in rotors, we only have to replace the dropouts. I have both sets, which means if we want to swap to a lighter wheelset for road use, I don't need to buy a whole new fork. Third, the springs can be changed to suit anything from a 150lb single rider to a 400lb tandem team. I can use this fork on another bike of mine by simply removing a spring. There's also a few color options. Alex@MTBTandems suggested this fork as an option, and I happened to know someone who had one needing a rebuild, so I dropped it off with Dean @ ATC Racing, and he built it up to our specs. You can't get that kind of service anywhere else. The only drawback is that it's a bit bulky for a coupled bike, so we'll switch to the DJ if/when we travel.

[edit] Sorry Stap, but we only have 5 inches of nice smooth travel, and it doesn't bottom. Can you get stiffer springs?

http://www.ozbikesports.com/images/tandemcomplete.jpg

tandemonium
09-30-05, 06:35 PM
Wow,
I'd like to thank everyone for spending so much time for the detailed posts. I hope this thread is not dead yet...more information....more....more...'too much is never enough'. Thanks again.

fyi
I have been running 2.1 Fire XCs on my FS single at 30psi. The tires drift predictably hooking up in the most unusual way. I haven't tried them on the tandem yet but I will now. I've also used various Michelin Wildgrippers - all 2.1 on the tandem at 65psi. My current favorite is the Wildgripper Country because of the wide, low lugs. It tracks well on compressed limestone, pavement and basic trail riding. They won't cut it much longer as winter approaches. I also ran the Continental XC 2.1 at 65psi this spring. They hooked up well on dirt and sod but found that they wear quickly on pavement. They were a good all purpose off road tire. So we have that portion of the bike in concert with your opinions.

It appears that purchasing a tandem with front suspension and disk brakes is a must for the riding we do.
That JP system...is it heavy? I never saw one before. The rear suspension seems like a nonessential option? I suspect it could be cost prohibitive to do a complete upgrade on our 'dale mt800. If we upgrade the mt800 I obviously can't go too cheap on the fork. Alex at MTBT suggested that we try a 4" ATC shock so as not to upset the geometry severely.

So, any opinions on the upgrade versus replacement issue?
Full suspension vs. Front suspension?
Feel free to recommend makes or models.

ricardo kuhn
09-30-05, 09:40 PM
That JP system...is it heavy? I never saw one before.
Actually not that much,,is about 320Grms and is super dupper rigid (side to side).
you need to remenber when Jp develope this stem front suspensions forks were on their Infancy and many of the Best bikes ever made (Yo Eddy's, Cunninhams,goats,,etc) were Not "suspension Ready" so installing a bouncy fork will destroy the magic exilibrium of the Legendary Geometry,
in that sense the STem is a far better option, the head angle remains the same, the standover does not change, anyway this stems are as good as most 2"-3" forks if not better.

Jp Only made about 35 of the latest model and about 12 experimental ones (I still have some of the Pieces), all of them sold I believe, exept for the one we are remachining for my tandem (we need to make some missing parts) they were pretty expensive about $350 retail for the reason they did not sell to well, they target a really narrow population basically you need to be a person that understand bikes and fisics to apreciate the advange, He sold at least two to japan and a few other to europeans (He race world cup MTB's and many of the pro's were his clients for their Own Bikes not the sponsor ones) specially if you compare it with a fork of the Era like the RS-1 or early manitou the are far better and the bike still handle the way is soppose too..

since they are a paralegrogram the angle of the bars and controls do not change, the grips just move up and down,,actually in reality most of the time the wheels is the one that moves and the hand remaind equidistant from your shoulders, I believe on the tandem you will feel the bars moving more, since the whole mass of body of the captain is loading the front wheel limiting the amount of the wheel movement...

If you want I can ask him to see if he knows of somebody selling a used one but is not going to be cheap since they are kind of a "Cult" among the few, I also need to take some fotos of his latest suspension bikes design and made about 7 years ago,,so so diferent that anything you will ever see..

Actually SOftride made a bunch of stems(from 1994 to 1996) with a similar design (Not as nice for sure specially in terms of rebound and damping) just do you self a favor and stay away from the aluminum model,,,believe me I have 16 stiches in my upper lip to drove it..

The rear suspension seems like a nonessential option?
Actually i think a Good full suspension works better than a hardtail since the whole bike moves Up and down at unison,,well kind of depending on loads,,what i'm trying to say is that the frame is more prone to move "Paralel" to the ground, when with the front suspension only the pivot is at the rear axle making the bike a little bouncy and very sensity to load shift specially when standing,,or maybe i'm just to picky and does not really matter that much.

stapfam
10-01-05, 01:17 AM
Expat
We do bottom out our Boxers, and this is gauged by a zip tie on the forks. This only ever happens on the fast rough Downhills, and if you saw the speed we hit those lumps on the trail at, you would understand why. We did initially use a Marzochi Freeride 135mm fork, and we got close but did not bottom these forks out. (Once again with the Heaviest weight springs, and oil change to 20 wt) Problem with these was that they were not 20mm axle, and when the Hopes with 200mm discs went on, the forks were flexing drastically.

I will not say the Boxers are the ideal fork for tandem use, but they work extremely well. are strong enough for the use they are given, and are economic to purchase and service. On top of that, for our use, they do work.The bottoming out does not bother us, as it is never felt, and does mean that we get full movement on the designed travel on these forks. Incidentally, all up weight is 400lbs so we are not exactly the lightest team around.

We use the panaracer 2.1's because they suit our type of terrain, and I do not understand why, but the sidewalls are constructed to "Help" eliminate snakebites. Cannot vouch for that, but of the 3 snakebites we have had this year- two were on the rear using Continental tyres, and the nasty one was at 35mph downhill on the front using an IRC Mythos. Never wear the Fire XC's out but deep splits in the tread area of the tyre, do mean that I change them frequently. I am lucky if I get more than 1,000 miles out of them.

On the suspension travel affecting handling. We went from 135mm to 150mm travel on our Dale MT. We did not notice any difference on handling at all, and that includes the downhills aswell. I do realise that a 100mm fork may give better steering control uphill, but that is not a problem for us. It is not so much the Travel that affects handling, but the ride height of the front end of the bike. This does look excessive when you look at the bike, but once you get two riders on it, the sag taken up brings the bike back to sensible height.

Brian
10-01-05, 02:10 AM
[snip]
So, any opinions on the upgrade versus replacement issue?
Full suspension vs. Front suspension?
Feel free to recommend makes or models.

First, some comments on tires again. Yes, the Conti's do wear quick. But we've got stacks of them. We have no way to transport the tandem, so we have to ride it to the bush. The terrain here is so different than what I used to ride in SoCal. There, you could count on dry, mostly loose dirt, with a bit of hardpack and a bit of sandy conditions. Here, we go from loose to hardpack to slick, wet rocks and roots to pea gravel and maybe even some mud. When choosing a tire here, the best you can do is pick one for some of the conditions and settle for a compromise on the rest.

Now, about the fork. If you get the ATC Racing one from Alex, I think you'll be making a good choice. If you ever decide to part with your tandem, you've added a bit of value. Or, you can always reconfigure it for some other use. I like the options you get from that fork. And as mentioned before, the serviceability and ease of replacing parts is much better than anything else on the market. I also feel that on the long wheelbase of a tandem, rear suspension is not needed unless you are getting into some really crazy terrain. Adding suspension up front will certainly add a level of comfort though. And a suspension post for the stoker, if they don't have one already.

stapfam
10-01-05, 02:55 AM
Now, about the fork. If you get the ATC Racing one from Alex, I think you'll be making a good choice. If you ever decide to part with your tandem, you've added a bit of value. Or, you can always reconfigure it for some other use. I like the options you get from that fork. And as mentioned before, the serviceability and ease of replacing parts is much better than anything else on the market. I also feel that on the long wheelbase of a tandem, rear suspension is not needed unless you are getting into some really crazy terrain. Adding suspension up front will certainly add a level of comfort though. And a suspension post for the stoker, if they don't have one already.

I do like the sound of that fork. Multi functional for multi bike forms.

I do agree about the rear suspension bit. We all know that Tandems do require heavy weight equipment, and Rear suspension is something that has only recently started working well on solos's. I doubt as to whether there is the expertise to make a rear suspension unit that will take a Tandems Weight and force that they are ridden. I know all the arguments on the solos about how rear suspension gives better traction, but that is only on the top end units. The rest do not work as efficiently, or cause problems. Mind you the stokers suspension post is a must for offroad. I know I have already mentioned it, but I now have a Thudbuster. This works. As to whether the 3" version is necessary, I would not like to say, but that is the one I have and I no longer need a Tandem with rear suspension and we are into some crazy riding, if not terrain.

Brian
10-01-05, 03:55 AM
Yeah, I can use that fork on another bike if I want, or just rebuild it, should it ever need that. It's great that it can go from a 9mm to 20mm axle, plus the travel can vary from 4-6 inches.

tandemonium
10-01-05, 05:52 PM
Tandemgeek;
What made the Ventana rise to the top of you list?

TandemGeek
10-01-05, 07:46 PM
Tandemgeek;
What made the Ventana rise to the top of you list?

Having started out on a '98 C'dale MT3000 hard tail, our upgrade to our first Ventana was a revolutionary experience in terms of stoker comfort vs. the hardtail bikes and the quality of the design, fabrication, and finish was on par with custom work... which is pretty much what each Ventana is. But, just as important was outstanding support of Sherwood Gibson and his very small staff in Rancho Cordova, CA: small company where the products were still built in-house by hand by someone who actually rode and raced the darn things. In fact, Ventana was the first to introduce full suspension tandems to the market back in the early 90's -- initially as a way of proving the robustness of the Turner / Gibson MFS rear suspension design. Sherwood campaigned the early Ventanas in off-road races through the 90's and used that experience to refine the design, something he continues to do to this day and for what is still a very reasonable price when compared to the other offerings from his peers and the major producers. The only reason we sold our first Ventana was because there were a number of major component upgrades I wanted to make and it proved more cost effective to sell the first tandem and to start over with a new frame and build it up with the new components than to piece meal the thing, e.g., 20mm Stratos S-5T replaced 9mm Stratos FR-5T fork, Chris King hubset replaced Hope Bulb, Hope Enduro brakes with 203/180mm rotors replaced Hope 04DH 180/160mm hydraulic brakes, SRAM drive train vs Shimano, etc...

Santana's original Dual Motos eventually proved to have a troublesome rear suspension and the company that produced the original design no longer exists, thus getting spare parts if difficult. They only reintroduced the Dual Moto last year at Interbike as a $10k IsoGird carbon framed collaboration with Titus and thus far I think only two or three have been produced. One is basically a display model built for the owner of Titus / IsoGrid, et al... and another is owned by a hardcore couple who race in the midwest.

The Ellsworth Witness has a dubious design history that I won't go into. However, despite some nits with the design the biggest problem is it remains a one-size-fits-all machine; too small for some and too big for others. Tony Ellsworth -- to the best of knowledge -- does not and never has been a big tandem rider and that's reflected in the design which has neither evolved nor been offered in different sizes. Not even sure who is producing the frames for him as they were for a while fabricated by a machine shop owned by the now defunct Meridian Tandem brand: nice workmanship though and a very cool finish.

daVinci: $7,500. Need I say more... great design and a great machine, but since we haven't seen the need for it's unique Independent Coasting System or multitude of gearing combinations, it's just not something we can justify in light of the Ventana's performance at a much lower price point even when built up using some of the most high end components on the market for off-road tandems.

Boulder: I saw a TSL back in '97 when we were buying our first tandem and it just didn't do much for me. They were also one of the pioneers of off-road F/S tandems, bringing a prototype to Interbike for the first time the same year that Ventana did. But, as I said, I just never connected with the folks at Boulder when I was doing research the way I did with Ventana and the tandems seemed to be a bit more expensive for what looked to be a less efficient design. I also believe Boulder has ceased to exist as a going concern.

Chumba Wumba: They are a downhill MTB manufacturer who built a tandem for one of their racers. It did not appear to be a well thought through design with respect to cross country riding and their experience seemed a bit limited. Not sure how many they've actually made or sold but, again, just an as of yet proven pedigree in my mind and not as good of a value as the Ventana.

The out of production GTs, Univegas, and some of the other limited production or off-shore bikes offered by places like Chucks just don't have the support structure behind them that Ventana has. Whether or not Ventana can remain around for the life of our tandem is about our only concern and, to a certain extent, most of the parts that could fail can either be replaced using off the shelf bearings or repaired or fabricated by a good machine shop that works with aluminum. Hopefully this won't be an issue, but one never knows with a small one-man-show like Ventana given the economic realities of the bicycle industry.

TandemGeek
10-01-05, 08:00 PM
Alex at MTBTandems has a photo of him and his wife airborne on their website. I think that's on their Ventana, which is a full suspension, if I recall correctly.

No, that's a photochopped image of a friend from Seattle named Jack Tomkinson with his girlfriend climbing Slickrock in Utah from a few years back. The way the photo was chopped makes it look like it's airborne, although it is a Ventana.

There is another photo on the Web that I've photochopped for the DoubleForte site that you'll also find at the daVinci site... it was taken back in the late 90s and the guy on the back was Greg Shepard, former publisher and editor of Tandem & Family Cycling Magazine. One of Todd Shusterman's "wrecking crew" race team captain's took Greg out to a BMX park for a photoshoot by TF&C's tandem reviewer and photographer David Morgan as part of an article on the DaVinci Symbiosis and that particular photo was taken on the last jump of the day... which, crashed on landing and sent Greg off to the ER with a broken clavicle.

You may also find a photo of Sherwood Gibson on board an '03 Ventana (yellow as I recall) getting some big air at a BMX track with one of his employees stoking.

To the best of my knowledge, Alex and Kim have not been caught on film doing any big-air on any tandem.

TandemGeek
10-01-05, 08:11 PM
General comment on full suspension tandems: You buy them for the stoker's benefit. 4" of travel will keep them out of the chiropractors office after aggressive single track far more efficiently than any shockpost. Pogo action can be a problem in very aggressive riding but the Ventana's pivot placement and rear suspension design is pretty good at minimizing it and, well, there are the lock-out rear shocks which work really well, particularly when you have someone on the bike who has a free hand to flip the switch on and off at the appropriate times.

Tires: 2.4" MotoRaptors are our current favs for all around use and loose or super technical terrain. We have a few pair of 2.1" IRC Mythos XCs for hardpack but, IMHO, bigger is better for tandems. You want to put as much meat on the ground as possible for maximum control, bite, and snake-bite resistance.

Brian
10-01-05, 10:30 PM
To the best of my knowledge, Alex and Kim have not been caught on film doing any big-air on any tandem.

I stand corrected. I haven't been to there site in a while, but I thought that was where I saw an image of an airborne couple.

stapfam
10-02-05, 08:52 AM
General comment on full suspension tandems: You buy them for the stoker's benefit. 4" of travel will keep them out of the chiropractors office after aggressive single track far more efficiently than any shockpost. Pogo action can be a problem in very aggressive riding but the Ventana's pivot placement and rear suspension design is pretty good at minimizing it and, well, there are the lock-out rear shocks which work really well, particularly when you have someone on the bike who has a free hand to flip the switch on and off at the appropriate times.

Tires: 2.4" MotoRaptors are our current favs for all around use and loose or super technical terrain. We have a few pair of 2.1" IRC Mythos XCs for hardpack but, IMHO, bigger is better for tandems. You want to put as much meat on the ground as possible for maximum control, bite, and snake-bite resistance.

Just done a fairly aggressive ride on My Dale MT and I can assure you that the Cane Creek Thudbuster works. Lumps in the terrain that were catching me on a telescopic suspension post were fine on the Thudbuster. Stayed seated on all the ride and absolutely no shock transitted to the Backside. This has been the best aid to speed travel over rough terrain, after the Boxers, and does make us think that Full suspension is not a necessity for comfort.

We weigh an all up weight of 400 lbs. and only use 2.1 tyres. No probems on rear grip, and we use 60 psi in front and rear. We have had 3 snakebites this year, (Not when using panaracers incidentally) so have reverted back to Panaracer Fire XC's as the tyre of choice, apparantly they "Help" in eliminating snake bites. We have found, from general XC experience, that a narrower tyre causes less drag and this is bourne out by out Tandem experience too. Admittedly, this is on our type of terrain which is Chalk paths covered in scree, thick sticky clay or Sheep grazed grass. Profile of the tyre comes into it aswell, but we have found that a rounded profile that is narrower, does not get gripped by the grass, bites through any mud or loose soil onto firm ground where we can get grip, and is less prone to skating across the scree. That coupled with the 6" travel forks and now the Thudbuster, means higher speed on the lumpier parts of the trail, and does not cause any terrain shocks to be transmitted to the frame, or at least to the saddles, which is where it matters.

It does depend on your type of terrain, and how aggressive you want to ride, but our set up is being refined continually and is currently the best possible for us. Now if we were riding hardpack all the time, this would require a different set up, and would also take us a while to sort. Once again from solo XC experience, fatter tyres, less travel on the forks, and even reverting bak to a non-suspension post for the Stoker would be the way to go. Whether I would enjoy that type of riding all the time would be a different matter.

tandemonium
10-02-05, 08:42 PM
As for our riding style, we tend to start on a rather tame trail then usually end up exploring whatever singletrack we encounter. Our ride this weekend was the most technical to date. I was motivated enough to contact Alex at MTBT for further info on the ATC Terex T-5. This is my contingency plan in case the fs purchase falls through. (homeowner's blues). We'll also have to convert to disc brakes as I can see us grinding through the rims quickly.

There was a new developement on the last ride. The timing chain jumped completely off the gears on a rocky and rooted climb. This was the stoker's first encounter with a failure of this kind while clipped in. All went quite well though, the drive line was restored and we gently pedalled out. I suspect the eccentric must be repositioned?

TandemGeek - you should be working pr for Ventana. That was a good sales pitch.

What rims, spoke guages, and brakes are you guys using that are surviving the beatings?

Brian
10-02-05, 10:39 PM
We've got Sun Rhyno Lites, laced to a generic 20mm thru-axle hub up front, and XT rear. No fancy double butted spokes for us - just straight gauge 14g stainless, painted black. We had custom titanium 203mm discs, but they were crap. Great heat dissipation, but really short life. Now we have Shimano XT 203mm discs front and rear. We're using Avid mechanicals, as the bike is coupled, and was supposed to be for touring. I've got a set of Magura hydros, just need to order some braided lines. Other than the ti discs, we've had no problems whatsoever.

stapfam
10-03-05, 12:43 AM
Hope Bigun hubs to Mavic Downhill rims with 14g straight gauge spokes. 20mm front axle and normal quick release rear. Brakes are Hope Mono m4's with 200mm discs.

Brakes are superb and can vouch for the quality of wheels. Both brakes and wheels are possibly over the top, but with our style of riding would prefer to be overbuilt rather than have a failure at speed.

ricardo kuhn
10-03-05, 11:48 AM
What rims, spoke guages, and brakes are you guys using that are surviving the beatings?
I run 36 hole Atomlab trailpimps with brass washers for the nipples since the rims don't have eyelets, i believe the make one call the DHX that comes with them, i run this rims because they have a lot of mass that hopefully will cool down the rims better (so far so good) and becuase they also have the tallest brake surface I ever saw with about 22MM .

if i was running only disc brakes is a million choices for downhill bikes from about 32 mm wide( and less) to more than 62MM (snow rims from surly)

the Hubs,,,hope Big-un's with really tall flanges and all the spokes coming from the outside of the inside of the hub, I run a 5 cross spoke pattern ussing DT Alpine triple butted spokes (2.2/1.8/2.0) with aluminum nipples (never have a problem running them since i'm the only one that touch them with the proper tools)...Oh to run the 2.2 you need to minidrill the hub since the spokes are wider than the holes on the hub.

the Brakes are divided in two sistem,,the rim brakes are Old school XTR V-brakes with XTR levers and DKG fork braces when I can (something the brake bosses are to far apart and I can not run commercial braces) and if I not find them I make them out of a Composite wood core material use on small airplane firewalls.
the Hydrolic brakes are made of C-2 levers upside down(right side on the left and viseversa) and the old Enduro four piston caliper running on stock pads and 205mm Hope five bolt rotors,, some say this Enduro brakes have more power than the Ti-six Hope's and so far i need to agree. (exept they don't modulate or cool down as well as the new ones

I think that is It,,,, Oh one more thing, i have some big-un hubs with QR type axles ussing a surly Instigator fork and then 2wheels with 20MM axle for heavy dutty work

stapfam
10-03-05, 12:13 PM
Update on the Rims for XC use. A standard XC rim will not stand up to the use it will be given. For really aggressive use then a full downhill spec rim is the one to use. If you are a little friendlier on the wheels then a "Freeride" quality rim is possible.

I personally use Mavic rims, so that is the numbers I will quote

XC717-- Xc solo use weight 420g and not up to offroad Tandem use, unless it is just smooth paved trails

XM719 which is a "Freeride" rim, Bit stronger than the XC717and weight of 460g

EX721 which is quoted as the strongest Mavic rim and for Downhill and Freeride at 590g

EX729 which is a full downhill rim, and is the one I use. Can vouch for this rim having had a couple of sudden deflations which could have damaged any other rim, but is still perfectly true.Weight is a hefty 675g so could be over the top.

Others will advise you on other manufacturers, and in particular the Rhyno Lite seems to be a favourite. These were my first set of rims on the Tandem, but wore out rather quickly with the V.Brakes. they worked fine, so no complaints, but Felt that with our aggressive riding style, some thing better was required.

Incidentally we only use 36 spokes, but on a 26" wheel, this is enough.

TandemGeek
10-03-05, 12:39 PM
Current F/S Ventana: 36h Velocity Aeroheat AT, Wheelsmith DH13 laced 3X, Chris King hubset w/20mm bolt-on through axle, and Hope Enduro 4pot hydraulic brakes 200mm F / 180mm R using Motul 600 brake fluid.

Previous F/S Ventana: 36h Velocity Aeroheat AT, DT Revolution laced 3X, Hope BULB (Big Un's Little Brother) hubset w/9mm QR axle, and Hope 04DH 4pot hydraulic brakes 180mm F / 160mm R using Motul 600 brake fluid.

Previous C'Dale MT3000: 40h Rhynolite, DT Champion 14g laced 3X, Coda/Hugi hubset w/9mm QR axle (and later, a Shimano HF-08 following the implosion of the Coda/Hugi hub), and Shimano XT V-brakes.

tandemonium
10-04-05, 07:21 AM
I recognized the consistency in your component choices. We presently have Rhyno Lite, 40 hole 2x on both ends of the bike.

Hope disc systems did not occur to me. What is the advantage to their design? I have been using Hayes hydraulics on my Enduro since 2002 and have been very happy with the power, reliability, and modulation. I was not considering a mechanical disc as cable corrosion is an issue with winter riding.

stapfam
10-04-05, 11:14 AM
I recognized the consistency in your component choices. We presently have Rhyno Lite, 40 hole 2x on both ends of the bike.

Hope disc systems did not occur to me. What is the advantage to their design? I have been using Hayes hydraulics on my Enduro since 2002 and have been very happy with the power, reliability, and modulation. I was not considering a mechanical disc as cable corrosion is an issue with winter riding.

Hope make brake systems that cater for all grades of requirement on bikes. The hope Mono M4's, which is the system I use, is a 4 pistons per caliper system, wheras most others are only 2 pistons. This in theory gives you greater braking power and modulation , but is only relevant when the other components of the system are up to scratch. They also make a 6 piston system, but have not found anyone that uses it to compare yet. I ride offroad, so long Alpine downhills have not been tried, but have used the system until the discs were smoking and no lessening of the braking effect was found. This was on the Sintered pads by the way,which are a bit harder, and may wear out the discs quicker. Not that I have found this after around 4,000 miles of use.

Can't tell you the advantages of their design, but they the simple truth is they work. They also make a system that has now been proved on a Tandem. I use 200 mm discs front and rear, but in hindsight, probably a 180 on the rear would be man enough. Disadvantages are that they are not cheap. Mind you, for a system that I fitted in january 2003, this has required less maintenance than other other brake system I have worked on. One change of pads allround, and a realignment once of the front caliper. Not bad for a system that in the UK is rated as probably the best you can get.

SugarHillGMC
12-31-05, 05:53 PM
I'm sure suspension tandems are fine for "SUV Posser Comfort types" but when is time to really Go For it and get on a rocky singletrack they become like "walking on a water bed" or so sprung on the forks and shock the suspension varelly move but you still have to deal with the extra complexity and Inerent flexion.....
again this is a very personal opinion, plus I really enjoy the challenge of picking the perfect line and the Raw feel the contact with the ground gives you.

SUV poser types? Try racing (at speed, a little too fast for your "perfect line") really fast on a nasty, rocky downhill- and this is just the first 5 minutes of a 2 hour race. On a rigid???? Been there, done that, will never do it again. At those speeds a rigid is like handlebars on a pingpong ball.
If you really want to rip- and keep your stoker really happy while going fast- in OUR humble opinion- its got to have suspension at both ends. Check out the teams that race in the northeast on really rough terrain- most are on F/S.
Oh and rocky singletrack? The singles that we ride with are usually surprised at the stuff we ride up, down and over. Again, we have done the same rides on a hardtail and in comparison, we ride faster and longer with F/S.

John S & Cathy B
Ventana CdeM (built by MTB Tandems- Thanks Alex!)
EFTA Tandem Division Champions
2001, 2002 & 2003

stapfam
01-01-06, 05:26 AM
SUV poser types? Try racing (at speed, a little too fast for your "perfect line") really fast on a nasty, rocky downhill- and this is just the first 5 minutes of a 2 hour race. On a rigid???? Been there, done that, will never do it again. At those speeds a rigid is like handlebars on a pingpong ball.
If you really want to rip- and keep your stoker really happy while going fast- in OUR humble opinion- its got to have suspension at both ends. Check out the teams that race in the northeast on really rough terrain- most are on F/S.
Oh and rocky singletrack? The singles that we ride with are usually surprised at the stuff we ride up, down and over. Again, we have done the same rides on a hardtail and in comparison, we ride faster and longer with F/S.

John S & Cathy B
Ventana CdeM (built by MTB Tandems- Thanks Alex!)
EFTA Tandem Division Champions
2001, 2002 & 2003


Can't talk about Full Suspension bikes of any type as I have never owned one. On solo's- the only fs bikes that work are the expensive ones- That are out of my price range and Tandem FS will not be cheap.

I ride a Dale MT that has Boxer Race front forks and 20mm axle. Uprated springs of course and a couple of mods to bring into Tandem Specification. In comparison to the Marzochhi Single crown Freeride forks we had before- they are Superb. As most of our riding is done XC we have found that this fork is ideal for us. That is the front end taken care of and the only problem with the rear was the stokers butt. To protect it, weight had to be taken off the saddle which did not help on the grip stakes on the faster lumpier downhills. All that changed when the Cane Creek Thudbuster was fitted. Vey rarely do I have to suspend myself away from the saddle, and that back wheel gets all the traction we need. A rigid does work better uphills and on a tandem this is still the case. Speed on the flat is generraly not a problem, but it is the downhills where a Full suspension will work better. Even that is limited to the roughness of the terrain, but by using the Thudbuster, we can not only stay with the fastest around- Due to the "Nobrain" downhill aspect of the pilot- There is not much that stay with us on any downhill. Including the Full Downhill solo rigs ridden by the other nutters out there.

SugarHillGMC
01-01-06, 11:34 AM
Insanity is hereditary. You get it from the Kids. Stapfam- well put.

Just before we had our Ventana built up we rode a Cannondale with a Marzocchi single crown fork and Thudbuster stoker seatpost. (sound familiar?) It was actually Cathy that suggested the upgrade to F/S and she took out a motorcycle bank loan to finance it. She was tired of getting the stoker saddle stuffed up her backside. We were able to ride most anything with the C'dale and won the first of our 3 series on that bike. We liked it but we REALLY like the Ventana. The brakes are outstanding- Hope 4 piston calipers, a fork that eats up the terrain- ATC Terrex (Alex's recommendation), Sun Big Mammoth rims, WTB Motoraptor 2.4 tires.... on and on- MTBTandems built us an awesome machine.

If the two of us could each pick out one thing that we like best- Cathy would obviously say the rear suspension- it allows her to continue pedaling through the sharp bumps (remember that with F/S her saddle stays the same distance from her feet) and the lockout is right behind her knee. I like two items (I know, I'm cheating) #1- the fork- NO lag between turning the bars and the front wheel responding, very different from a single crown fork and #2- the brakes- one finger, great stopping, NO fade.

For us it was a very good upgrade. We would do it again in a minute.

John S & Cathy B

stapfam
01-01-06, 03:31 PM
Insanity is hereditary. You get it from the Kids. Stapfam- well put.

Just before we had our Ventana built up we rode a Cannondale with a Marzocchi single crown fork and Thudbuster stoker seatpost. (sound familiar?) It was actually Cathy that suggested the upgrade to F/S and she took out a motorcycle bank loan to finance it. She was tired of getting the stoker saddle stuffed up her backside. We were able to ride most anything with the C'dale and won the first of our 3 series on that bike. We liked it but we REALLY like the Ventana. The brakes are outstanding- Hope 4 piston calipers, a fork that eats up the terrain- ATC Terrex (Alex's recommendation), Sun Big Mammoth rims, WTB Motoraptor 2.4 tires.... on and on- MTBTandems built us an awesome machine.

If the two of us could each pick out one thing that we like best- Cathy would obviously say the rear suspension- it allows her to continue pedaling through the sharp bumps (remember that with F/S her saddle stays the same distance from her feet) and the lockout is right behind her knee. I like two items (I know, I'm cheating) #1- the fork- NO lag between turning the bars and the front wheel responding, very different from a single crown fork and #2- the brakes- one finger, great stopping, NO fade.

For us it was a very good upgrade. We would do it again in a minute.

John S & Cathy B

Wrote a reply about 1 hour ago and lost it so I will try again

First of all I must state that I do not ride full suspension so I cannot make comments about the merits and disadvantages of one system over another. What I can tell you are our experiences of riding a Hardtail.

I can say straight away is that it is surprising how similar efficient parts and ancilliaries are for a performance Tandem. I use the Hope MonoM4 brakes and they are awesome. Our Modified Boxer forks work for us, and on our local terrain are good. They may not be a recognised Tandem fork, but if set up properly they work as efficiently as some unit costing a darn site more. Took a bit of sorting initially, but they do work. On the wheels- Hopebigun hubs on Mavic EX729 downhill rims. These are strong, possibly too strong, but if you saw some of our descents, and the speed we hit them at, I would rather have an overbuiltwheel than fold on me. On tyres we differ and probably down to local conditions. I use a 2.1 Fire XC, although am currently trying a 2.0 Kenda Karma that seems to have a great deal of promise. The fire XC gives us grip , which a wider tyre does not- We skate across the mud instead of biting through to the solid ground underneath, We still get grip on "Green" chalk, or as much as makes it safe, whearas a wider tyre lost grip, and then there is the Grass that Clings to any tyre, but a narrower tyre does get less drag. That drag is an important factor on our "Enduro" rides so matters a lot.

Then it comes to the all important part of stoker/ rear suspension. Before I got the Thudbuster it was a conventional-cheap suspension post for me. A lot of the time I had to be raised off the saddle for comfort. Not a problem uphill, and not a great one on the flat. Downhill was different though. Those lumps hurt so that I had to be off the saddle. No great help in keeping the weight over the back wheel and we would lose traction and braking effect. Plus the fact that if the stoker is out of the saddle- then pedalling efficiency is impaired. Then Came the Thudbuster (3"version) This enables me to remain seated everywhere without any form of pain. The pilot does give me warning of any major lumps or dropoffs taken at speed,so I do still get off the saddle sometimes, but in general I remain seated. No loss of pedalling efficiency, no loss of traction and NO PAIN. It works for me. Full suspension would not help us uphills, on the flat a bobbing frame might not help efficiency, and I doubt as to whether we have the courage to any faster than we do downhills. As to differing position on the Seat post to leg length- The Thudbuster moves in an arc and does not affect me at all.Where it matter though is in the pain stakes. I do not have a problem until about the 10 hour mark (Enduro riding) and I doubt as to whether full suspension would help on that score. To date I have not found it necessary to go Full suspension, but must agree that if the stoker finds it painfull, then making it more comfortable for the stoker is a must.

dubbelop
01-03-06, 05:19 AM
Then it comes to the all important part of stoker/ rear suspension. Before I got the Thudbuster it was a conventional-cheap suspension post for me. A lot of the time I had to be raised off the saddle for comfort. Not a problem uphill, and not a great one on the flat. Downhill was different though. Those lumps hurt so that I had to be off the saddle. No great help in keeping the weight over the back wheel and we would lose traction and braking effect. Plus the fact that if the stoker is out of the saddle- then pedalling efficiency is impaired. Then Came the Thudbuster (3"version) This enables me to remain seated everywhere without any form of pain. The pilot does give me warning of any major lumps or dropoffs taken at speed,so I do still get off the saddle sometimes, but in general I remain seated. No loss of pedalling efficiency, no loss of traction and NO PAIN. It works for me. Full suspension would not help us uphills, on the flat a bobbing frame might not help efficiency, and I doubt as to whether we have the courage to any faster than we do downhills. As to differing position on the Seat post to leg length- The Thudbuster moves in an arc and does not affect me at all.Where it matter though is in the pain stakes. I do not have a problem until about the 10 hour mark (Enduro riding) and I doubt as to whether full suspension would help on that score. To date I have not found it necessary to go Full suspension, but must agree that if the stoker finds it painfull, then making it more comfortable for the stoker is a must.
Would you please tell which combination of elastomers you use? My wife & stoker weighs about 130 lbs and has two white (= the softest) elastomers in her Thudbuster. Still she often has problems remaining seated, to which I must add that I also cry out for bumps so she can lift up a little bit. The Thudbuster has never come close to "bottoming", no matter how big the lumps are. So if you have any tips on this, I would like to hear them!