carmie

Hi, everyone, first time poster here.

My husband and I have been occasionally riding an old Cannondale tandem for a few years now
and are now interested in purchasing something a little nicer.

I am very interested in Davinci's ICS system, because it sounds like it might help solve the
problem of strength differences between two riders.

We're going to be trying out a few tandems tomorrow morning at a bicycle shop in Elk Grove
Village, Ill ( many thanks to senior poster, Duppie for the referral).

My question has to do with an email comment I was given by another bike store here in Wisconsin regarding
DaVinci's ICS system:

"As far as the Da Vinci ICS, not many tandem makers use it because it makes the tandem a lot more unwieldy. First off, it's a much more complex system to keep tuned up. It also hurts the handling if the two riders aren't pedaling in sync (balance can be thrown off and it's much easier to scrape a pedal on the ground)."

Has anyone with this type of coasting system experienced any of these problems?

Many thanks in advance,

Martha
Wisconsin

TandemGeek

I'll defer to daVinci owners for first hand impressions of the ICS performance, maintenance and reliability...

However, that said, I'd love to know the name of the shop in Wisconsin so I can put it on a "do not call list" for folks looking to find bike shops that know something about tandems. I would venture a guess that whoever you spoke with has not ridden a daVinci, never mind worked on one.

Thankfully, the shop in Elk Grove is a pretty good one that does know a thing or two about tandems. Have a great time there and let us know how the test rides go.

WebsterBikeMan

While I've not used the DaVinci, it is true that "not many tandem makers use it" - basically DaVinci uses it, and Bilenky will if you ask them. Perhaps a few others would on a custom build. As for the "because", I would suggest that they don't use it because they don't perceive enough demand.

"A lot more unwieldy" is a bit over the top here.

It is slightly more complex as far as keeping tuned up, but only very slightly. An extra (short) chain to lubricate; a 4 speed rather than 3 speed shifting unit on the front.

As for in/out of sync, they say it is fairly natural to stay in sync. Basically if you're both pedaling, you are both pedaling at the same rate. A brief coast by the stoker will put the pedals in any choice of phase you like. Pedal strike is only likely if you are somewhere near 180 degrees out of phase. Anywhere from 0 to 90 is not a problem - common arrangements for fixed systems are 0, ~5 degree (captain leading) and 90 degree. There's another thread (search for Davinci In2ition vs Co-motion) that has had quite a few DaVinci riders chime in.

The tradeoff is one of
- proprietary parts in your drive train (but less proprietary parts overall than in the largest manufacturer's (Santana) models).
- Slightly more weight due to the extra drive train parts
- some of the $ spent on the ICS could have gone to make a cheaper bike or upgrade other components
- communication "through the pedals" not so quick
+ very wide gear range (go faster at the high end, and climb steeper hills at the low end)
+ good for discrepancies in ability (more easily tired rider can coast at "any" time - but preferably not when starting up from a stand-still )
+ arguably smoother shifting up front (smaller steps between rings).
+ either can coast while clipping in without both coasting; coasting doesn't require warning.

The simple summary of most discussions of the DaVinci is that nearly every DaVinci owner is happy with it, and most experienced non-DaVinci owners can't imagine switching. I think this means that the DaVinci is very good at what it is, and what it is is not for everyone. For quality, they're right up there in the running with the other top makers.

rdtompki

Martha, my wife and I bought a daVinci about 4 weeks ago and I'll post at some length this evening when I've got 15 min., but I disagree strongly with the "a lot more unwieldy", "much more complex" and "hurts the handling" offered up by a bike shop that obviously didn't want you looking at a daVinci. More to follow this evening.

merlinextraligh

This made me think of the paceline thread. In most circumstances, I wouldn't think this would be a big issue. However, riding in a paceline I would think might be difficult because the stoker isn't getting the same feedback through the pedals.

Do you ride your Davinci in pacelines/groups, if so, is this an issue?

rdtompki

Martha,
WebsterBikeMan is pretty much right on and I'll preface everything else I have to offer with the disclosure that we're the furthest thing from tandem experts having all of 400 miles. We in our early 60's and reasonably athletic.

My wife and I returned to bicycling last August after a 20+ year hiatus. We came to the conclusion that riding together on a tandem would be more enjoyable than doing 100K and 100mi rides on our singles. The search began for first a used tandem followed by test rides on new tandems.

Good used tandems do take time to find, but represent excellent value. We did find a pristine 1994 Santana Sovereign for $1500 (asking). In the end I thought we might spend as much as $1000 for seats, tires, tubes, cables, CF fork (maybe), convert barcons to STI or similar, complete tune-up, but the bike was in excellent condition, just hadn't been ridden for a long time. We were a bit spoiled by having logged miles on our Shimano 105-equipped singles which somewhat raised the bar for equipment.

We passed on that particular bike and shopped at a tandem-only bike store that handled Co-motion, Santana and daVinci. We test rode all three over the course of two visits, the Co-motion once and the Santana and daVinci twice each.

Co-motion - in test ride configuration this was the only tandem without a CF fork. Vibration through the brifters was noticeable almost immediately and became objectionable. Seemed to handle very well and judging by the number of owners would have made an excellent choice.

So it was down to the Santana and daVinci. These are both great rides in my opinion. If you locked out the ICS on a daVinci and ignored the shifting/gearing differences there wouldn't be much to choose between them. Both seem to handle very well. There is a slight weight difference (I believe), but my wife and I are not racers although we are interested in doing faster (for us) paced longer rides. DaVinci does have some proprietary parts: FD, RD, Chainrings and the ICS intermediate shaft assembly. The FD should never wear out. It is only customized ot support the four chainrings. The RD is a modified SRAM unit for compatibility with the Campy brifters. The chainrings are steel and should be long-lived. Really, its only a question of the ICS mechanism and I was willing to accept this one area of unusually non-standardization.

In my mind the two areas that define the difference are the ICS and the gearing, but I should mention that you can buy a daVinci with Ultegra STI Brifters and a triple chainring.

Gearing: I do think the quad chainring which provides very wide gearing and fast shifting is a plus. At first it doesn't seem as though you would need the wide range, (24-60 front, 11-32 rear), but a tandem unless in the hands of a pair of strong riders does need/want low gearing and on a slight downhill the 60 tooth (actually 30x2) chainring really comes in handy; these things can really fly downhill. We've since changed out the 11-32 for a 12-27 so we can keep our cadence more easily in our overlap region, but this is an individual thing. If we were riding something with anything but a short stink over 8-9% grade I'd put the 32 on, but this is an age thing!

ICS: We do pedal in phase. I can feel when my wife is slightly out of phase, but she gets in phase in a hearbeat. Usually, the out of phase situation is the result of my coasting for a second let's say for a pothole, something I shouldn't have to do. Does it hurt the handling? Not that I've noticed, but if I had one of my 200 lb. sons on the back out of phase in exactly the wrong place I'm sure I'd notice. This is almost not relevant since getting in phase is very natural. Regarding us scraping a pedal I don't know how many tandems are pedaling hard going around this sharp a turn and it's the most natural thing in the world for stoker and captain to have the pedals level or inside pedal "up" when cornering at the coast. You won't find ICS a cure-all for differences in strength. If one rider has a very circular, even pedal stroke and the other more up/down application of force it will take some time to smooth things out; I can feel when my wife is tiring on a hill in too low a cadence and if on the other extreme I get the cadence too high she can't keep up. I would think either drivetrain requires the captain, usually the stronger rider, to find a cadence at which the stoker can apply his/her balance share of the effort. When I select too low a gear on a short hill and the cadence start to drop I know I've put my wife in a situation where she can't input her "share" at that cadence - my bad.

Paceline: I agree with Merlinextraligh that pacelines are a bit difference on a daVinci. My experience is limited, but the stoker can't see the gap and I can provide direction through the drive train. Still, it's workable and not a big deal for us since mostly we are riding with singles and the dynamics are so different that I find this to be more of a challenge that the difference in the drive train.

Verbal communication - this isn't going to be much different between conventional and ICS, but I can't control the load on the derailleurs through the timing chain so I'll call out "shifting" for the RD if there is a load, but often it's enough if I unload the pedal slightly. We use "back off" for the FD where I really need the stoker to ease up, but I'm voting for something more to the point.

The DV FD is not indexed and takes a bit of getting used to, but the Ergo shifters are very popular and considered to be more robust than STI. If got to concentrate a bit when I go from my single to the tandem.

Summary: My wife and I really like the daVinci and I think the generall feel and gearing and a small price difference was probaly more of a factor than the ICS. I'm an engineer by trade, but finally stopped agonizing over the possible loss of efficiency due to the extra chain. If we werereally go-fast, yonger folks that might have weight in favor of a conventional drive train, but for use the few percent didn't make much difference. Would we have been happy with the Santana - absolutely.

Other tandems out there of course, but we bought what we could test ride from a tandem-only dealer who took very care of us.

Sorry for the long post - hope this helps.

mikefranktroymi

We owned a Burley Rumba before we purchased our DaVinci. We enjoyed the Burley, but since I am quite a bit a stronger rider then my wife the daVinci was a no-brainer for us. The handling, is great. The quality is great and we are very happy with the bike. As far as handling, we are more insync then out of sync.

The davinci also saves from blown out knees due to poor communication. I think the shop that bad mouthed Davinci is shameful. It reminds of the time I was in a shop and the salesman looked a purchaser straight in the eye and said, "if you going to ride high mileage like 30 miles on a ride you better not look at anything less then ultegra" just another sample of pure bunk.

Abram

1) "More unwieldy" Huh? I guess tandems are unwieldy to start with, and ICS just makes it worse.

2) "Much more complex to keep tuned up." Only additional piece to "tune" that I can think of is the stoker eccentric. There are two eccentrics rather than one, but you don't adjust those very often and it's not difficult to do either. There are two additional freewheels, but those are not items that require tuning (I suppose eventually they'll need to be replaced).

3) "Hurts the handling if not in sync." Only time I notice any effect from the state-of-sync is when we both stand at the same time. Some offsets make us wobbly standing, and I quickly sit back down if we end up in this condition. With respect to another comment that the stoker can "easily" choose the sync position; my stoker reports difficulty doing this. I don't argue with her, since I haven't tried it myself, but I don't understand the problem. Usually I can't tell what our sync-state is, unless I catch a look at a fortuitious morning or evening shadow on the road.

4) "much easier to scrape a pedal" I can't imagine having a problem hitting a pedal on the ground on pavement. Based on some measurements I just made, this would be a 30degree lean on our bike with the stoker pedal all the way down, so I guess it's possible. (7" from end of pedal to centerline of bike, 3.75" from bottom of stoker pedal to the ground; tan^-1(3.75/7)=30degrees) But this sounds like more of a complaint for an out-of-phase non-ICS bike. With ICS, the stoker is just as responsible as the captain at avoiding a pedal strike. If the team is coasting through a leaning turn, each rider has chosen the position of their feet during the coast. And when either rider starts to pedal again, they shouldn't be any more likely to hit ground as a rider of a single bike.

To MerlinEL's question; can't really comment since I don't have enough experience on a non-ICS bike to compare, but I do find following a paceline with singles to be tiring as captain.

We're happy our Davinci bike. I would list the advantages as:
- start & clip in under stoker power without captain cranks spinning
- no need to coordinate or call out a brief pause in pedaling to reach for a water bottle or relieve a cramp
- easier availability of high gears (a 30T sprocket for a 60T effective big ring is easier to find and shift than a 60T chainring)
I'm sure we'd be happy with a non-ICS bike as well, but if we were buying a second bike, I'd seriously consider another DV.

zonatandem

We do not consider ourselves 'tandem experts' but are experienced tandemists; have pedaled over 225,000 miles as a tandem duo in 34+ years.
Have ridden many tandems, including the daVinci. We pedal 90 degrees out of phase and been doing so since the mid-1970s; that's our personal preference.
Enjoyed test riding the daV and overall it's a great tandem built and backed by some extremely knowledgeable and conscientious folks. If you like the ICS, for whatever reasons, go for it!
Others have pointed out small advantages and disadvantages with the ICS system.
The bike shop in WI that bad-mouthed daV have probably never ridden or worked on one.
Have had some so-called tandem 'experts' tell us many things . . . most of them wrong!
Definition of an expert is 'a know-it-all without experience.'
Enjoy the ride TWOgether!
Rudy and Kay/zonatandem

masiman

I can't add much to above.

I have found a greater chance of pedal strike but it is pretty minor. It's not only the corners but the occasional short high bumps. You also have to remain aware of curbs that you might otherwise take closer as your stoker may not raise their pedal to avoid a strike. Overall, a little extra thought but nothing requiring post-secondary education to master.

You do need a signal to let the stoker know they need to ease up or stop, verbal or non-verbal. This is needed for pacelining, approaching stops, shifting gears, etc.

They are simpler to mount with child stoker kits. You remove the stoker crankset and hook the stokid to the jack gear. Very clean looking and you don't have to worry about the stoker crankarms. You can even give the stokid (stoker too) a different chainring to give them a different ratio than you. I.e., you can keep a higher cadence and they can keep a lower cadence or vice versa.

carmie

Thank you all so much for the thoughtful comments!
We will be trying out a daVinci, Co-Motion and a Santana this morning.
Should be an interesting and enjoyable fact finding trip to the bike shop!

Martha

justcrankn

"I am very interested in Davinci's ICS system, because it sounds like it might help solve the
problem of strength differences between two riders."
I don't understand how the ICS will help with that.

"First off, it's a much more complex system to keep tuned up."
We took an extended test ride on a DiVinci. The owner/dealer was unable to work out some strange noises from the area of the ICS. Your average bike geek/LBS will not be familiar with the ICS.

"It also hurts the handling if the two riders aren't pedaling in sync"
There have been long threads on the merits of different pedal phasing, so many consider it important. The bike will handle differently with different phasing. IMO this is only important when standing.

I have thousands of miles stoking with ICS. It was ALWAYS a PITA syncing the pedals after coasting. IMO the ICS shines on shorter rides, slower cadences, and rides where the stoker is distracted with other duties, such as feeding the team, reading maps, or answering the phone. I think the WI bike shop did a good job by pointing out the possible disadvantages of the DaVinci ICS. You just need to weigh the disadvantages against the delight of coasting at will.

Stray8

Well, for example if you're riding with a kid stoker, you won't spin their legs off their pedals if you sprint...


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apage4u

"You can even give the stokid (stoker too) a different chainring to give them a different ratio than you. I.e., you can keep a higher cadence and they can keep a lower cadence or vice versa. "

Now I have seen the light. Thanks for posting that answer. I always hear "strength difference" but it really boils down to cadence difference. Here is where the ICS can help if you change the stoker's chainring to correct for cadence differences.

Eurastus

I've got a very long write-up on da Vinci tandems at my blog here: https://www.eurastus.com/2007/08/da-vinci-tandems.html. It's a couple of years old, but everything in it is still valid. Give it a look.

As an aside, for cadence differences, take a hard look at the cool da Vinci three-hole cranks (no extra charge on their top models). These are uber-cool and work great. I discuss these at length in the blog.

TandemGeek

You know, I find most bike shops are always more than willing and able to point out all kinds of possible disadvantages of tandems, ICS or not. In fact, most bike shops that don't know much about tandems also find working on all tandems to be a PIA.

Stray8

I agree. Up here in NYC most of the LBSs probably view tandem bikes to be an eccentric oddity, much like unicycles. Up here most don't even have an older tandem hung up on display. I understand that the majority of their business income is derived from spandex-weenies with discriminating tastes and ridiculous amounts of disposable income so they have to cater to what keeps them in business.

I was in an LBS this weekend and no kidding this one customer asks them if he needs to bring in his bike (again) to put on a replacement seat he just bought. He must have been a really good customer because they told him very carefully that he could certainly bring it in if he wished to...or else he could do it himself if he had a metric allen wrench...


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osurxbiker

So what happens when this person drops a chain on a ride or gets a flat? Will AAA come out and change a flat tire for you on a bicycle?

After building up our tandem (and working on all of my half bikes) there was nothing more complicated about working on the tandem than the single. The cables were longer, there was the eccentric and timing chain, but other than that things were the same. In a shop things might get crowded if the bike stands are spaced too closely for tandems. Though to be fair most shops don't work on many tandems.

Stray8

Yeah, I stared at him for a moment actually thinking he was just kidding around but their response showed that he was being serious (and that they were used to him...). Obviously the type of guy who seeks the reassurance of having official "expert" opinion on how to do anything. He looked like an ordinary guy too but probably never changed a single flat tire in his life or ever will...


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justcrankn

I think you could do that on any tandem, not just the ICS. Then the captain will never know what position the stokers crankarms are in. That would make cornering and going over big bumps interesting.

masiman

True dat ! The biggest drawback on the traditional would be the inability to quickly adjust to a preferred phasing for corners and such.

TandemGeek

The mechanicals are straight forward, what makes tandems a PIA for shops aside from their size is trouble-shooting and fixing problems that are germane to having two riders on the bike who may or may not have the best technique and/or minor adjustment issues that won't manifest themselves in a workstand or when a lone 'person who goes by the title mechanic' takes it for a spin in the parking lot.

Reference the other thread running on putting chain watchers on a Calfee and the problems that tandems often times have with overshifting either the granny or the big chain ring. Then we have the tandem teams who can never get their front chain to shift into granny when they're climbing, squealing brakes that can't be made to not squeal, disc brakes that always rub and don't have any stopping power. How about shifting on brand new tandems that just doesn't stay dialed in or tandems that ghost shift when teams are climbing out the saddle.

Out on the sales floor, we have just the good old problems with newbies shopping for a tandem who go for test rides on the one tandem the shop bought on spec after getting all pumped up by a manufacturer's sales rep at interbike a few years ago and not having a clue how to instruct new tandem teams how to ride a tandem. Is it any wonder folks who are just curious come away from those terrifying test rides saying, "no thanks: I just don't know how folks ride those things".

I'll leave it at that. Clearly, if you can and do work on your own bikes and really do know what you're doing and have the tools to do most of the routine stuff, then tandems are a piece of cake once you figure out the eccentric and each tandem's little qwerks and/or how critical pre-stretching the derailleur cables is to indexed shifting performance. It's important to know that disc brakes don't work all that well when they're brand new, and so on.

justcrankn

At one chain of shops I've been in the salesguy says their bread-and-butter is the family that comes in and gets several bikes on the spot. They'll move a lot more of these lower-end bikes at a higher margin with less overhead than the high-end bikes that the bike-geek comes in to look at and try ten times.

Stray8

Perhaps, but I would have supposed that more families would buy their basic bike fleets at a Toys R Us, Wally World or Target which the LBS can't compete on price (versus perhaps...service and maintenance?). I can see more individuals and/or childless couples go for higher end LBS road cycles.

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carmie

Thanks again for all the useful comments. My husband and I drove down to Elk Grove Village and spent two hours riding one of Vince's DaVinci's Intuitions. It was a great experience!

Since we are present owners of a Cannondale mountain tandem, we did not try any of the other tandems. I know, I know, a Cannondale probably doesn't compare to one of Vince's Santanas or CoMotions, but we really were interested in the idea of ICS, and for us, two middle aged tourers, it would work very well.

One of the challenges that Vince encountered when setting up a tandem for us for the test ride was the
similarity in our sizes: we are both 5'8" and 160 lbs.

Am I mistaken in my impression that tandems seem to be designed for riders who are not so evenly matched in size? We rode a medium frame, and he was forced to raise the stoker seat by quite a bit to accommodate my measurements.

Thanks again for all your comments!

Martha