Tandem Cycling - Tires..... again

Ive gone through about 8 pages of old threads looking for opinions and didnt really find a whole lot so I thought Id start a new thread and get some current advice.

We have a Cannondale Road 3 that came with Conti Gatorskins. One thing Ive noticed since we got this bike (We're both pretty strong riders) is that this bike is SLOW. We both have to kill ourselves on the tandem to even get close to what we can do on our singles.

This got me to thinking yesterday about my one and only experience with Armadillos on my single. I put a set on my single bike, went out and rode 10 miles and felt like someone had tossed an anchor out behind me. Im starting to wonder if the rolling resistance of the Gatorskins is whats causing our tandem to feel like we're riding in quicksand.

We ride on crappy roads. Theyre not heavy with debris, they're just old and we're a pretty heavy team. I weigh in around 270 and my stoker is around 190. We both ride Conti Attack Force tires on our singles although Ive dabbled with 4000S's, Pro Race 2s and some other tires. Flats have never been an issue for us.

So.. can anyone recommend a tire that has less rolling resistance than the Gatorskins but still have some puncture resistance? Id even be willing to go up in size provided it will fit in the frame. The Cannondale has a pretty beefy fork so I dont think getting a larger tire in would be that tough.

We've always had good luck with the GP 4000 (either S or non-S) in 700x25 (feels more solid in the corners than 23s).

Also make sure your disc brakes are not rubbing.

We've always had good luck with the GP 4000 (either S or non-S) in 700x25 (feels more solid in the corners than 23s).

Also make sure your disc brakes are not rubbing.

The brakes seem to be okay. I give the wheels a spin before we take off and adjust the caliper distance if there is any rubbing.

I guess we could give the 25s a try. That worries me a little with our weight but I really believe those tires are killing us given the weight we're pushing and the condition of the roads.

Friends of ours ride a Co-Motion and recently switched from 28mm Gatorskins to the Conti 4seasons in 700x28 and claim less rolling resistance and better ride feel due to the high thread count.

I am running 700 X 28 Continental Ultra Gatorskin on my Co-Motion and 2 weeks ago when we road with 8 other tandems I was braking on the downhills to keep from running them over. I have some nice wheels on my Co-Motion and the wheels make a huge difference on rolling efficiency.

I am running 700 X 28 Continental Ultra Gatorskin on my Co-Motion and 2 weeks ago when we road with 8 other tandems I was braking on the downhills to keep from running them over. I have some nice wheels on my Co-Motion and the wheels make a huge difference on rolling efficiency.

Whats your weight like compared to the other teams? We fly downhill.. it just on flats we feel like we are working our butts off to really not go anywhere. My single feels that way when Im on a really crappy road. The tandem feels that way all the time unless youre on super new, smooth black top.

We have always found the Gatorskins to be good for rolling resistance. I don't think you will find anything significantly better.
Are you saying that the speed you average on a flat ride is slower on the tandem than what you could both do on singles? It certainly shouldn't be, but I can't see how it could be because of the Conti's.

Bizarre... even with 32mm touring tires, our tandem is quite a bit faster than a single on the flats.

Also, I second the recommendation for 25mm GP4000S.

We ride on crappy roads. Theyre not heavy with debris, they're just old and we're a pretty heavy team.

Are you riding on chip-seal or some other type of road surface that's less than smooth? If so, what PSI are you running?

Have you experimented by letting a little air out of the tires during a ride to see if you can smooth out the road feel? Or, conversely, increasing your tire pressure by 10 to 15 psi over normal to see how that might effect road feel?

I only ask because we tend to run very high PSI tires since we typically ride on very smooth roads. However, the minute we hit chip seal we experience the same massive increase in rolling resistance that comes from having a tire that's trying to ride up and over all those bumps instead of comforming to it.

Not knowing where you live, my gut tells me that you may do better to ride on 32mm or even 35mm tires at something like 80 PSI if you spend most of your time riding on 'rugged roads'.

Again, more details regarding the road, any experimentation you've done with different tire pressures, etc. would help.

The roads arent chip seal thankfully. Just asphalt thats out in the country and well used.

We run the Gatorskins right at 120 PSI. I figured given our weight we needed to keep them at the max pressure. I could try dropping them back some and see if its any better. But yea, the tandem just beats us both down. Ride a century on the singles? No problem. Even as out of shape as I am right now, I wouldnt hesitate to go out and ride a century. 35 miles on the tandem and we're both ready to get off.

The issue with the tandem is we both feel like we're killing ourselves and going considerably slower. Its been that way since we've had this thing and one of the reasons we havent ridden it more than we have. Its just slow and not as much fun as the singles which kind of stinks because we do enjoy the time together on the tandem.

If you aren't predisposed to dropping $100 to experiment with a set of some larger volume tires like the Jack Browns (http://www.rivbike.com/products/show/jack-brown-green-blue/10-092), you could do a short experiment by riding your C'dale's Gatorskins inflated to something like 105 psi in back and 100 up front for a test ride. Just do your best to avoid the obvious snake-bite hazards just to see if there's any difference in road feel.

This is probably the best bet since I'm not sure how wide the bead seat in on the rims that came fitted to your C'dale R3. I would think they should be wide enough for a 32/33mm tire, and if it has cantilever brakes then you should have more than enough tire clearance. Ultimately, the larger volume and lower PSI tires are what 'should' give you a much improved ride without putting you at risk of a pinch flat short of nailing a train rail or some other type of road hazard.

We looove our Conti GP4000S 25 mm tires (http://www.conti-online.com/generator/www/de/en/continental/bicycle/themes/race/racetyres/grand_prix_4000S/gp4000S_en.html). They are light, supple, have low rolling resistance, and with its VectranBreaker belt (the yellow), it has pretty good flat resistance. We haven't had a flat yet, since we got them last fall.

http://www.conti-online.com/generator/www/de/en/continental/bicycle/themes/race/racetyres/grand_prix_4000S/img/gp4000s_quer_uv,property=original.png

However, our team weighs 295 lbs, and if we were a lot more it might be a different story. Neither are our roads particularly rough. So 25 mm GP4000 may be too light for you, and they don't make a 28. The 25 mm weighs 230 grams.

You could try using the GP4000S 25 mm, and if it doesn't work out on your tandem it would be great on one of your half-bikes.

The do-everything tire is the Grand Prix 4-Season (http://www.conti-online.com/generator/www/de/en/continental/bicycle/themes/race/racetyres/grand_prix_4_season/gp4season_en.html), of which there is a 28 mm version. It has a double VectranBreaker belt. The 25 and 28 mm weigh 240 and 260 grams respectively. These would be a nice improvement from the Gatorskin.


http://www.conti-online.com/generator/www/de/de/continental/fahrrad/themen/rennrad/rennradreifen/grand_prix_4_season/img/grand_prix_4_season_de,property=original.jpg

Could this possibly be a fit issue and not really tire related?

Just a thought..................

+1 on the Continental GP4000S in 25mm. We switched to these last year since we had such good experiences with them on our singles. Over 1000 miles and they hardly look worn. Great handling tire. No flats so far,actually my wife and I have ridden over 8000 miles without a single flat on Continental GP4000 and GP4000S on our singles . We ride very bad roads too.

Our combined weight is just under 300lbs.

JayC; you never mentioned the size tires you presently have on the tandem. With your team's wieght; you need some thing in the 32mm width range. The teams that are less than 300lbs can get away with the skinny tires; 450+lbs is a whole different ball game.

I wasn't going to respond because I haven't tried many tires, but then I saw that you're using 700x28 Gatorskins at only 120psi with a 460# team. I agree with nfmisso that this seems too low. My wife and I come to about 320#, and the tire-pressure suggestion graphs I found suggested that we use 700x28 at about 130psi. (!) I've since tried lower pressures and settled on 120psi each. It seems nice enough to me... certainly feels as good as when I ride my single.

EDIT- I realize I should elaborate on "certainly feels as good as when I ride my single", I mean, the tires seem to feel as good as on my single. My stoker isn't as avid a rider as I, so on short rides we can use all our energy, and the tandem feels fine going up hills on these rides. On longer rides, I remind her often to save some for the later hills, or "it's a long ride", etc. She eases up, which is good, but it puts a little more effort on me so we use a bit easier gears. The bike feels as I'd expect for the two of us to mix our abilities and get it up a hill.

...the tire-pressure suggestion graphs I found...

Here is an example, from Bicycle Quarterly.

Optimizing Your Tire Pressure for Your Weight (http://www.bikequarterly.com/images/TireDrop.pdf)

http://farm4.static.flickr.com/3586/5831062393_c0b1bf5ffa_z.jpg


Tire inflation for 15% wheel drop in relation to wheel load and actual tire width.

Example: Rider and bike weight: 100 kg. Weight distribution: 45%/55%. Wheel loads: 45 kg/55 kg. Tire pressures for 20 mm tires: 125 psi/155 psi. Tire pressures for 37 mm tires: 45 psi/53 psi.

For heavy riders/bikes, narrow tires require very high inflation pressures, and wide tires are a better choice...

Assuming a 50/50 distribution for your 270/190, 460 lb. team = 230 lbs. per wheel. This graph only extends up to 154 lbs. per wheel. It seems safe to say, however, if this article has any merit, and you wish to have your tire pressure within the manufacturer's recommendation, that the choice isn't between 25 and 28 mm, but between 28 and 32 mm.

Here are unsourced formulas from a post on the BF (http://www.bikeforums.net/showthread.php/737068-Tire-width-proportioned-to-rider-weight?p=12679127&viewfull=1#post12679127):

Use the following formulas to determine proper tire pressure as a function of rider weight and tire section:

Tire Width=20: Pressure(psi) = (0.33 * Rider Weight in lbs) + 63.33
Tire Width=23: Pressure(psi) = (0.33 * Rider Weight in lbs) + 53.33
Tire Width=25: Pressure(psi) = (0.33 * Rider Weight in lbs) + 43.33
Tire Width=28: Pressure(psi) = (0.33 * Rider Weight in lbs) + 33.33
Tire Width=32: Pressure(psi) = (0.17 * Rider Weight in lbs) + 41.67
Tire Width=37: Pressure(psi) = (0.17 * Rider Weight in lbs) + 26.67
Front Pressure = .9*Rear Pressure

For example, the OP weighs 185 lbs and uses 23mm wide tires, so Rear Tire Pressure = 0.33 x 185 + 53.33 = 114 psi. Front Tire Pressure = 0.9 x 114 = 103 psi.

This works out for the 460 lb tandem team as:

25 mm 195 psi
28 mm 185 psi
32 mm 120 psi

We are a 305 lb. team. We tried Gatorskins and also thought they were really slow. We also think that Conti 4000s in 25c are very fast and reasonably durable tires, better than most. However! At 460 lbs., your experience with tires will be different than ours. I'm not real big on exceeding the pressure that's written on the tire. I'm also not real big on exceeding the max tire pressure suggested by the rim manufacturer for a particular tire width. Perhaps others can comment on their adventures in this regard. We've never had to do that.

28c Gatorskins have a max pressure of 116 lbs. Very few 28c tires have a recommendation this high or higher. The only other high pressure 28c tire I've used is the Vittoria Rubino Pro Tech which has a max of 115 in 28c. It's not a terribly fast tire, but decent.

Not to sound like a Mr Smarty Pants, if it is tire or pressure related, are you confident in the accuracy of the gage when inflating to 120psi?

In other words, is it possible the gage reads higher than actual pressure.

Another thing I notice is that if the spokes are not tight, not so much real loose, but just low on tension the bike feels dead.

We are no where near as light as many posting here, but round off close to 350 currently. Our roads are mostly smooth, but some do have a bit of wear and much exposed grain to the asphalt. Some roads do feel fast and others feel slow. The gadgets tend to back this up when comparing MPH vs HR.

!20 psi rear, 115 psi front, UltraGatorskins in 28.

The bike fit comment could be considered, also, on some rides I have a stoker that is peddaling, but not killing it to "keep up", not saying she is not pedaling, but sometimes the scenery is more important. As she states, "no lying now" with her HR playing on my bars.

I doubt I have the answer, just some other ideas.

PK

Great stuff here.....

My stoker puts in the work. I know she isnt back there phoning it in. I can feel when she's taking a rest and thats not very often.

Fit is an interesting point. What we did on fit is have the guy from the bike shop who fit us on our singles fit us on the tandem. I am convinced my fit is somewhat off. I dont feel great on the bike and am exhausted in the upper body after 30 miles. Supposedly the cockpit measures the same as my Pinarello but I just dont see it. I was thinking we needed to take the bike to a tandem-centric shop and have them fit us on it. It doesnt help that we're both around 6 feet tall.. thats also made finding a tandem we can both fit on tough.

As far as tire width, we have disc brakes on the Cannondale so brake clearance isnt an issue at all. I just dont know how wide the rims are and what they can accommodate. At this point tho, Im willing to try about anything. We both ride 23s on our singles and flats have never been an issue for either of us.

Not to sound like a Mr Smarty Pants, if it is tire or pressure related, are you confident in the accuracy of the gage when inflating to 120psi?

In other words, is it possible the gage reads higher than actual pressure.

I dont think so. Im using a Joe Blow Pro pump and its pretty much the only one I have left that is accurate. I have 2 Air Tower 5s that the gauges have both broken on and I also have a Joe Blow Sport that the gauge is broken on. Im reasonably confident that the JBP is right.

IMHO -- either your partner is loafing, or you aren't getting your efforts synchronized well.

Now I have very little experience riding with adult stokers, but what riding I have done with them has gone well. Steady effort is the key on a tandem. If you're frequently going into your "red zone" to charge up a hill or close a gap, you're probably going to suffer a lot, because the tandem responds only about half as much to your anaerobic efforts as a single would. So you burn up all your matches and don't really have anything to show for it.

BUT -- if you can keep a steady sub-maximal effort going, you can cruise at 20 mph into a headwind for hours...

Cadence can also play a very bid role. On my single I'm never under 90, but my wife's "power" (mine as well - we're both seniors) diminishes rapidly above 90, so I'm frequently pedaling at a lower than natural cadence. We'll start to spin out, I'll shift and find myself straining a bit in the next higher gear so I've either got to try a different chain ring or accept going slightly slower in the prior gear. And those last 50 yards at the top of a small hill where you just grunt a bit or stand on your single; well, until you're really communicating well the only one doing the grunting is the captain and standing takes some practice. Doing that 20 times on rollers does take a toll.

Doesn't seem like much, but it can wear one or both of you out very easily in 20-30 miles

Wondering why no-one has mentioned the Schwalbe Stelvios. Roll pretty good, fairly puncture resistant. So I'll throw them out there.

Personally I find the 700X28mm gatorskins the best all round tire for tandems, although there is a trade off between suppleness and toughness.

I'm with the guys who think comfort is affecting performance. If you start with your road position you often will go up 1-2cm and use a 1cm shorter stem and improve comfort. You need to be extra comfy on the tandem because it's harder to get up and move around.

Ritterview put up a very useful post that illustrates the tire pressure problem for tandems, which is that tires and rims are only designed for so much circumferential pressure in the case of tires, and so much lateral pressure in the case of rims. If you look at the 143 lb./wheel value in the BQ chart, you'll see that line pretty much intersects the highest recommended inflation pressure for the very best tires of each width.

Here's Mavic's chart of maximum tire pressures for each tire width:
http://www.mavic.com/sites/default/files/download/tirepressurechart_eng.pdf
From their chart:
23c = 138 lbs.
25c = 131
28c = 117
32c = 103

One can exceed these rim pressures, but they'll bow out sooner from brake track wear. I don't know of a 32c tire with a max pressure of over 100 lbs. Also, wide tires with high pressure ratings are usually slow, because they have heavy casings. Your C'dale probably came with 19mm wide rims. You shouldn't fit tires over 28c on such rims. If you want to go wider, put on 24mm rims, Velocity Dyads being popular for tandems.

However IMO, the what-tire-to-run problem is a separate problem from the why-does-our-tandem-feel-slow problem. Your bike will feel and get faster with more practice. It's the tiny differences in pedaling style between captain and stoker that have by far the largest effect. That's what makes your legs feel tired and the bike feel slow. What makes your arms and shoulders feel tired is not fit, it's that you're working too hard to control the bike. All that gets better with team practice. Our team has mostly given up riding our singles in favor of riding the tandem. This has made a huge difference in our speed and endurance as a team. Different teams will have different results, depending on how easily the team synchs up. We solve the effort difference between captain and stoker by both wearing coded HRMs so we can keep our HRs synched up, too. That makes a big difference over a long day, both in speed and emotional climate, as one team member doesn't get more tired than the other.

.... Supposedly the cockpit measures the same as my Pinarello

Hmmm. Although some get away with that, I personally can't. Our tandem is set up with my bars a couple cm closer and higher than on my singles, plus I use a 2cm wider bar.

Oh, and we're currently a 450# team, (don't tell Maggi I said that in public!), and currently ride Bontrager RaceLite HardCase 32's @ 120 psi. That is over the "Max Pressure", but not enough to worry about.

Cadence can also play a very bid role. On my single I'm never under 90, but my wife's "power" (mine as well - we're both seniors) diminishes rapidly above 90, so I'm frequently pedaling at a lower than natural cadence. We'll start to spin out, I'll shift and find myself straining a bit in the next higher gear so I've either got to try a different chain ring or accept going slightly slower in the prior gear. And those last 50 yards at the top of a small hill where you just grunt a bit or stand on your single; well, until you're really communicating well the only one doing the grunting is the captain and standing takes some practice. Doing that 20 times on rollers does take a toll.

Doesn't seem like much, but it can wear one or both of you out very easily in 20-30 miles

My woman is a masher. I kind of float between spinning and mashing and can do either comfortably. I prefer spinning and when Im riding alone, I keep my cadence around 95-100. She stays in the 60-70 range and likes to push the big gears. I dont mind riding either way and often switch back and forth because it takes less of a toll on my muscles and cardio to switch it up.

I do try to keep the cadence lower tho so she doesnt spin out and like I said, I can work fine under those conditions and I feel like we have a pretty uniform effort.

Whats your weight like compared to the other teams? We fly downhill.. it just on flats we feel like we are working our butts off to really not go anywhere. My single feels that way when Im on a really crappy road. The tandem feels that way all the time unless youre on super new, smooth black top.
I would say that the most of the other teams we rode with weighed as much or more than we do, there where a couple of teams that where lighter. We were the strongest tandem team on the flats and we left the others and pulled a bunch of singles most of that ride. I do run the PSI at about 115 to 120 on the 28mm tires. We are faster on the flats on the tandem than she is on the single and I think I am faster on the tandem on the longer rides (over 30 miles). I am not sure since we ride the tandem 90% of the time and 100 % on rides longer than 30 miles. Hope you figure why it feels like you tandem is slow.

....... It's the tiny differences in pedaling style between captain and stoker that have by far the largest effect. That's what makes your legs feel tired and the bike feel slow. ......

+1

there will always be a slight difference between the two riders, and at different locations around the pedaling stroke, one person may be pushing, and the other not, tiring both out faster than a single.

tandeming requires a certain amount of relaxation - 'Remember the Force" as in Star Wars. If you try to force things, it will be worse.

Regarding tires, we're on Kenda Kwest 32-622 (500lbs team) at 95 psi (rated 85 psi). I am considering Armadillos 38-622 rated at 100 psi. We have a '94 Trek T50 we purchased a couple of months ago - it had 23-622 on it, which even for me riding solo on it were way too small. OEM it had 38-622.

My woman is a masher. I kind of float between spinning and mashing and can do either comfortably. I prefer spinning and when Im riding alone, I keep my cadence around 95-100. She stays in the 60-70 range and likes to push the big gears. I dont mind riding either way and often switch back and forth because it takes less of a toll on my muscles and cardio to switch it up.

I do try to keep the cadence lower tho so she doesnt spin out and like I said, I can work fine under those conditions and I feel like we have a pretty uniform effort.

Mine too. And she likes to go fast. So, on level sections, I often have to tell her to please take it easy, "let's rest here and just cruise a bit at a nice pace because I'm going to need your help on the big hill coming in a couple of miles". Like others said, it's surprising how little you can ease up on level ground on a tandem and still get your legs freshened for an upcoming hill. But you may have to remind eachother to do that.

I have to change my previous answer... When we're both fresh, the tandem seems to behave like the mix of our singles, to the point that I think our tires are fine and the pressures are pretty good. When we're fresh, and going through rollers, it feels pretty similar to the single. But my stoker doesn't get out on longer rides as often as I do. So, on the tandem, I don't really have the same expectations of going up hills at certain speeds.

Lots of good information is mentioned in the posts above. Tandems however have such an advantage on the flats over singles that I feel the problem is not primarily with the tires. Not enough information to hazard a guess what the problem id but I have a suggestions to try to eliminate possible issues:

Speedometer properly calibrated on tandem? Maybe your computer thinks you have 23mm tires and you are going faster than you think! hah
Ride the tandem by yourself. On the flats if you can go faster than with the stoker - well I will let you draw your own conclusion....
Try with higher pressure. We are a 290 team an ran 28 gatorskins up to 130 I suspect you could go a little higher if your are confident in your tires and rims..
Try with lower pressure, as low as you dare.
Does the tandem track well? At your weight if you are working at keeping it straight then your tires are wasting power scuffing the pavement.
You looked at the brakes before but check again.
Turning the wheels easily - with tandem elevated do the wheels coast to a stop and turn back and forth before stopping?
Borrow wheels?
Borrow a tandem to see how you and the stoker feel on it?

All stuff that you have probably thought of and or checked already but best to eliminate without assuming anything.

Good luck, I am sure if you are systematic you will find the problem.

Wayne

PS my money is on calibrating the computer.

Do you have a regular fairly flat ride that you do? How long does it take on the tandem, you solo, and stoker solo? Just trying to get some idea of the relative speeds. To give you some idea we do a 19 mile ride that is moderately hilly. With similar efforts we take 58 min on the tandem and solo 55min and 70min (captain/stoker). On a dead flat time trial we are a little bit quicker on the tandem than I can do solo.
BTW I measured some Conti GP 4000 700/25 and Gatorskin 700/28. There is actually less than 1mm difference in width between them.
Also we do not notice any real difference between the 2 tyres. We run them at 120psi and have a team weight of 300lb.

PS my money is on calibrating the computer.

Garmin Edge 705 so that would be a no ;)

You didn't say (or I missed) what you mean by slow. We've ridden a lot of different sizes in our 35 years of tandeming. We thought that the 25 mm Gatorskins were a little faster, but we had more punctures than I was comfortable with (we are only a a 255lb team). The ride was just too harsh at pressures that guaranteed no punctures. The 28's fixed that. I would never say that the 28's are slow though. With a little effort we can cruise in the low 20's on flat ground, even though my stoker is a 13 mph rider. For your team weight I would be reluctant to ride a 25mm tire.

Frank and Terry

Im not real keen on the 25mm tire, at least not at this weight.

We're both 18-19 MPH group riders and can go out and do a 16-18 solo depending on the day and how saucy we're feeling. The tandem is a struggle to even match that tho.

We took it out last night with the 28mm Gatorskins at maximum recommended pressure, The only thing I can say about that is running the tired at only 115 makes the bike REALLY hard to control. Every thing the stoker does gets amplified 3xs up front. She waves a car by and the whole bike pulls to the left. We dont have that problem with an extra 20 PSI in the tires.

We did manage to average about 18.8 over a pretty hilly terrain with some long climbs in there. It was probably the fastest ride we've ever had on that thing and I dont know if it was lowering the tire pressure or what.

Ive got to do something with the cockpit tho. Im going to flip the stem tonight which will raise the bars up some and maybe not make me feel like Im leaning over so far all my weight is on my hands.

The only thing I can say about that is running the tired at only 115 makes the bike REALLY hard to control..

That would be the added "float" you get from having a softer sidewall. It's one of the things that I don't like about running higher volume / lower pressure tires. Again, thankfully we live where most of the roads are very smooth and allow us to run the higher pressures that yield a much more confidence inspiring ride. The down side is when you encounter a less than smooth road surface or, worse yet... chip seal... the massive increase in rolling resistance that comes from the hard tires bouncing over all of those imperfections sucks the life out of ya. Again, it happened to me last Friday on my single bike and, adding insult to injury it was a 2mi climb with a 5% - 14% pitch... psssst. Let out a little air and experienced a massive improvement in comfort and reduced effort.


It was probably the fastest ride we've ever had on that thing and I dont know if it was lowering the tire pressure or what.

My money's on the lower tire pressure. Pump them back up with the extra 20 psi and see what happens.

Seriously, playing around with different tire pressures is one of the easiest, least expensive ways to "tune" a bike's performance, and the changes don't have to be dramatic to have a noticable difference. As I've noted, I tweak the PSI in our tires or even use different size tires as needed to adjust to different road conditions temperatures and the like. Although I've now started to simply run the larger 700x25's nearly all of the time now that I've been able to get my hands back on 1/2 a dozen or so.

Again, we're another team that tips the scales in the 275 - 290 lbs range, which is far less demanding when it comes to tires vs. teams who in the mid-300's, 400's or higher... to include the multi-seat tandems.

We are a 180/130 lb. team and ride 28mm gatorskins. You outweigh us by almost 50%; that is significant. Higher pressure might be the key, but you will be pushing those tires to the limit. I feel like a wider tire, with 120 psi might help.
When you are on a flat stretch, are you actually slower? I find that if we try to accelerate or climb with our single buddies, we wear out. We have alot of mass to accelerate...remember inertia...and you have even more mass to deal with. I find that on a flat or rolling road, I can go about 2-3 mph faster with the same effort as on my single. Therefore, we sometimes fall back from stoplights and on hills, but easily make up for it after. This requires patience. It also does take some time to get into synch with your stoker and put in equal effort. Years ago, when we started out, we had the opposite problem-we rode the tandem almost exclusively and my sife kind of lost her skills and me being the stronger rider back then, became dominant. I was, unbeknownst to me, taking over and she was doing less.
Also, fit is hugely important. For 20 years, I rode a large Burley, so my wife wouldn't be too cramped in back. For the last 2 years, I have been riding a medium Santana, which is perfect for me and just about the same dimensions in back for my wife. Dealing with the large Burley was exhausting, especially when stopped!

Are you riding on chip-seal or some other type of road surface that's less than smooth? If so, what PSI are you running?

Have you experimented by letting a little air out of the tires during a ride to see if you can smooth out the road feel? Or, conversely, increasing your tire pressure by 10 to 15 psi over normal to see how that might effect road feel?

I only ask because we tend to run very high PSI tires since we typically ride on very smooth roads. However, the minute we hit chip seal we experience the same massive increase in rolling resistance that comes from having a tire that's trying to ride up and over all those bumps instead of comforming to it.

Not knowing where you live, my gut tells me that you may do better to ride on 32mm or even 35mm tires at something like 80 PSI if you spend most of your time riding on 'rugged roads'.

Again, more details regarding the road, any experimentation you've done with different tire pressures, etc. would help.Do you have evidence that lower pressure in the same tires is faster on rough roads? Tire testing says that higher pressure in the same tires is always faster on both smooth and rough surfaces, though as you say, the measured resistance on rough surfaces is much higher. I've never tested it on the bike, however, confining my tire and pressure testing to my smooth and repeatable rollers.

Im not real keen on the 25mm tire, at least not at this weight.

We're both 18-19 MPH group riders and can go out and do a 16-18 solo depending on the day and how saucy we're feeling. The tandem is a struggle to even match that tho.

We took it out last night with the 28mm Gatorskins at maximum recommended pressure, The only thing I can say about that is running the tired at only 115 makes the bike REALLY hard to control. Every thing the stoker does gets amplified 3xs up front. She waves a car by and the whole bike pulls to the left. We dont have that problem with an extra 20 PSI in the tires.

We did manage to average about 18.8 over a pretty hilly terrain with some long climbs in there. It was probably the fastest ride we've ever had on that thing and I dont know if it was lowering the tire pressure or what.

Ive got to do something with the cockpit tho. Im going to flip the stem tonight which will raise the bars up some and maybe not make me feel like Im leaning over so far all my weight is on my hands.

If you are matching the speed you can do on your singles for a reasonably hilly coarse I would say that the tandem is performing well.
You probably just need to get used to the different feel of a tandem.

Do you have evidence that lower pressure in the same tires is faster on rough roads?

Google is your friend; it's all over the place. But none is as compelling as our personal experience.

Bear in mind, we're not talking about running 28mm tires at 70psi or something silly like that. The suggestion is to experiment with different pressures where the delta is running 5 psi - 15 psi more or less than spec. on a given tire so that riders can decide for themselves what could be better without getting into ALL of the other variables that can made a certain tire have more or less rolling resistance than another.

If a somewhat more compliant tire seems to help, the next logical step is to go to a larger volume tire designed to run at a lower psi if you're a sport / recreational team where the added aero drag at higher speeds from the wider tire profile isn't a big concern.

Again, the down side is a different ride feel that can be disconcerting at first and may even seem like the bike is moving slower when, in fact, it's not. It's taken us 13 years to be weaned off 23mm tires after realizing that 25mm is still pretty darn narrow.

For the sake of objectivity what is your average speed on your single for a given route, what is your wife's average speed for the same route and then finally what is your average speed over the same route on the tandem under similar conditions. Hopefully that goes without saying.

Google is your friend; it's all over the place. But none is as compelling as our personal experience.

Bear in mind, we're not talking about running 28mm tires at 70psi or something silly like that. The suggestion is to experiment with different pressures where the delta is running 5 psi - 15 psi more or less than spec. on a given tire so that riders can decide for themselves what could be better without getting into ALL of the other variables that can made a certain tire have more or less rolling resistance than another.

If a somewhat more compliant tire seems to help, the next logical step is to go to a larger volume tire designed to run at a lower psi if you're a sport / recreational team where the added aero drag at higher speeds from the wider tire profile isn't a big concern.

Again, the down side is a different ride feel that can be disconcerting at first and may even seem like the bike is moving slower when, in fact, it's not. It's taken us 13 years to be weaned off 23mm tires after realizing that 25mm is still pretty darn narrow.Yes, of course it's all over the web. It's the conventional wisdom. You know me well enough by now to know that I believe in the efficacy of questioning authority. IME, I haven't seen it. My experience is from brevets, where one sees a lot of different ideas on frames, wheels, and tires. I drop the fat tire guys just as fast on chip seal as I do on smooth asphalt, running my Vredesteins at 140 for all roads on my Trek 5200. I've never passed a rider on smooth and then had them get me back on chip seal. Fat tire guys like Jan Heine I don't drop. He was just as fast before he started importing the Bois, though.

With many frames and forks it's undeniable that lower pressure feels faster on rough surfaces, and may even be faster if one counts in the physiological factors of being shaken. I remember that well from my boyhood, when a friend's Schwinn tank cruiser felt faster on gravel than my 3-speed English racer. But it wasn't. It's tolerable on my Trek. I did a mountain century with a friend who was test-riding the latest Willier, on boutique wheels and high pressure tires. He claimed he couldn't feel the difference between smooth and chip seal. The Conti test data is the only hard data I've seen on this, and my brevet experience is the only real-world competitive data I have, unless you have some hard data from your testing.

I'm currently in the process of rebuilding my Trek, so I took out a CAAD9 that I've built up while I'm messing with the Trek. I put on the Trek's Rolfs and Vredesteins and let 30 lbs. out of the tires in deference to the C'dale's aluminum build. Even so, it was about twice as rough to ride as the Trek, even though it has the high zoot carbon fork and all the rest of it. If that was what I had to ride all the time, I'd certainly be trying different tires and pressures.

Another data point for the OP: I went out on a single this evening, for the first time in over a year. I rode a fairly easy course, 34 miles and 1200' of climbing. I was 1-3 mph faster on the flat on the single, depending on wind direction, and 4 mph faster on the climbs. I averaged about 2.5 mph faster than the tandem does over this same course. We have our Speedster dialed in and we are well synched. We are the fastest coasting tandem we have encountered, including those with Rolfs, which we don't have, and teams much heavier than we are. We have a fairly aggressive position for a tandem, mine being about the same as on my singles. However, I'm a much stronger rider than Stoker, hence the difference.

One interesting note: I found I was pedaling circles on the single most excellently. We climb mostly in the saddle on the tandem. Must be good pedaling practice. I also noticed that I preferred to climb out of the saddle more on the single than I used to, even though we seldom do much of that on the tandem. Must be good for leg strength, too. I used the same gears on the hills that I used 2 years ago, so that was good to see, too. I'm 66.

I drop the fat tire guys just as fast on chip seal as I do on smooth asphalt, running my Vredesteins at 140 for all roads on my Trek 5200. I've never passed a rider on smooth and then had them get me back on chip seal. Fat tire guys like Jan Heine I don't drop. He was just as fast before he started importing the Bois, though.

Y'all keep going to the extreme examples like Heine with 40mm tires on singles and other "fat tire" bikes. I don't buy into that either: check my blog regarding the "stretch" VBQ made on Cervelo's tire testing for Roubaix.

I'm suggesting fine tuning air pressure, or going from a 28mm to 32mm on a tandem with a 460lb team IF lower pressure in the 28's yields the desired change. Not slapping on a set of 'fat tires'.

Do you have evidence that lower pressure in the same tires is faster on rough roads?

The only evidence I have seen is provided by "Tom A" in this thread: http://forum.slowtwitch.com/forum/Slowtwitch_Forums_C1/Triathlon_Forum_F1/Interesting_Rolling_Resistance_discussion_P1906332-3

Now rolling resistance one way or another is, IMO, a pretty small effect -- much lower in magnitude than the aero drag advantage of a couple on a tandem. So, IMO, switching tires isn't going to make a seemingly-slow tandem fast.

The thing is that the op has said that they averaged a speed on a fairly hilly ride that was comparable to what they can do on their singles. This is about what I would expect, and on a flat ride they would be faster.
So the tandem isn't slow at all, it probably just feels like it is slower because it isn't as light and nimble as the single bikes they are used to.

The thing is that the op has said that they averaged a speed on a fairly hilly ride that was comparable to what they can do on their singles.

Where do see the OP talking about a hilly ride? I'm only seeing, "We fly downhill.. it just on flats we feel like we are working our butts off to really not go anywhere." in post #6... ?

It might help if the op would post what kind of tandem they are riding and what it weighs, how it is geared and what wheels are on it.

It might help if the op would post what kind of tandem they are riding and what it weighs, how it is geared and what wheels are on it.

First post in the thread: Cannondale Road 3 (http://www.bikeforums.net/showthread.php/743225-Tires.....-again?p=12781169&viewfull=1#post12781169)

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First post in the thread: Cannondale Road 3 (http://www.bikeforums.net/showthread.php/743225-Tires.....-again?p=12781169&viewfull=1#post12781169)

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Head in butt!