Clydesdales/Athenas (200+ lb / 91+ kg) - Speed and the 26" wheel
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05-07-08, 08:39 AM
I am wondering if anyone has experienced this issue.
After 3 seasons on a bike that was improperly sized for me (and happened to have 700c wheels) I decided that after numerous wheel issues with both the stock and better wheels, that I would check out the 26" wheeled MTB world since so many in this forum have reported good results. I bought a 96 Giant Iguana and later found nearly the exact same bike in the dumpster. I restored it to its former glory and I ride them both now.
The only thins is that I miss the speed of a road bike. My rides seem to be harder work for a lower speed. I tried putting smooth 1.95" tires on one of the bikes with only nominal improvement.
My question is this:
Has anyone put 32-35 mm tires on and gotten close to some of the speeds that they got on a road bike? Are there higher pressure tires that will allow an MTB to close the speed gap a little?
BTW - I know MTBs are geared lower but that doesn't seem to be the issue here as I can get those speeds with the current gear set, I just can't do it easily or in a way that was as effortless on the 700c bike.
I'd love to hear from anyone who has dealt with this as well.
05-07-08, 09:28 AM
I have 1.35" semi slicks on my MTB pumped up to 70psi and it definitely makes a difference over the 1.95 knoblies. However, what I really think makes the difference is the large chainring only being 44 tooth.
05-07-08, 09:32 AM
I have 1.50" slicks on my GF Marlin at 100psi. They're fast :D
05-07-08, 10:22 AM
I put 26 x 1.25 90 psi tires on my wife's hybrid and it cranks pretty good now. You may be limited due to rim width. Newer MTBs usually have 20mm wide rims which will take very narrow tires while older ones have wider rims and 1.5 is about the narrowest that will work.
05-07-08, 11:33 AM
I've got 26x1.50 Nimbus 'dillos on my Hardrock Sport, and it flies. Honestly, speed wise, I can't tell a huge difference on flats. Downhills, I run out of gears compared to my (now former) Trek FX so that limits top end to the lower 30's. Uphills, the suspension slows it down. Overall, though, I average around 15mph for a week's riding, which is about .5 mph less than what I'd average on my 700x32c tired Trek.
Now, that being said, when I lay the hammer down (so to speak) I bet if I didn't have the suspension fork I'd notice no difference. I've passed roadies and blasted beyond 30mph on straightaways, while also relaxing on the way in today and enjoying the nice smooth ride when compared to the jarring 110psi ride of the 700c's on the Trek FX.
Overall? Love it. I'm going to pick up a Surly Long Haul Trucker soon, and will give another comparison then, but I really love the way my 26's ride.
05-07-08, 12:02 PM
Are you sure nothing is rubbing?
Are the bearings free moving, greased and adjusted well?
Was your 700c bike a drop bar bike? Whether it was or not, the riding position could be the culprit since the top energy use for a cyclist is typically overcoming wind resistance. Since your other bike was too small, you may have been more aggressively positioned while riding... This potential difference, and the possible increase in wind resistance, could be part of the problem.
05-07-08, 12:22 PM
Actually the other bike was too big. It is a 57cm and I normally take a 54cm frame. I didn't know that when I bought the thing though. It was a clearance bike and the salesman was just trying to unload it I suspect. It is a hybrid (Sirrus) so the dropped bar thing doesn't really apply. ALso my position on all three bikes is pretty similar. I noticed a real increase in comfort on long rides with a 170mm crank as opposed to a 175mm crank on the Sirrus.
As for parts, I went over everything myself and all is in good order but you make some good points and any of these could weigh could factor in.
05-07-08, 07:07 PM
I have done a little experimentation replacing 26 x 1.95 knobbies with 26 x 1.25 smoothies and it made the bike ride a lot easier/faster. This particular (cheap) bike has noisy drivetrain issues so it is sitting in the corner now waiting to be fixed, so I don't have any long-term experiece with the 26 x 1.26 smoothies, but I will say that you have to get enough psi in them so as to not get pinch-flats, and (the particular ones I have, at least) being thinner-skinned, they are likely to flat easier. Since you have two almost identical bikes you can do side-by-side comparisons using different tires (if you have the time, money and patience)...you want to be sure your rims will handle the new size properly (you can do a search on this site or look on sheldonbrown.com for a chart)...I know biketiresdirect.com is one site that has a lot of different 26 widths and treads.
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