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  1. #1
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    Wider tires, less rolling resistance, what about taller tires

    Just curious, been reading up (sue me, love to read) on rolling resistance. I found a study done by people from Schwalbe, in which they tested tires width and pressure differences.

    It seems that running a wider tire at lower pressure, reduces rolling resistance.

    Now my question is what about the height of the tire?

    Example, Schwalbe Little Albert is 28x2.1 (more like 1.9) while other tires i have are 29x2.1 (more like 2.0).

    What are the pros/cons of running a taller tire if any?

  2. #2
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    Noooo this is wrong, part right but taken to literally and to much to the extreme!!

    There will be a ideal width and pressure for the terrain your riding and your weight, bigger or smaller than that for that terrain will be slower so it's kinda got a point.

    For my 230lb errm build, 1.7's role best on roads for me, 2.2's for XC, 2.4's for ROCKY stuff.

    Taller rear wise as the power is transfered you lose more power through the casing, but just rolling over rocks taller adds to the suspension effect so down rocky trails it'll role better, RK 2.2 is a great rear tyre as it's not that wide but super tall, so roles fast and has good cushion.

  3. #3
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    thanks Turv, good info there..

    I was already factoring in the difference in tire pressure. The ability to run lower pressure with a wider tire.

    In terms of comfort, the taller (bigger diameter) tire is the way to go correct?

    Im not hardcore, but i do like going as fast as i can...is the trade off between weight/size worth the extra comfort? Or is it too much for too little?

  4. #4
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    Taller ='s more extra suspension travel in short, wider = slower but more traction for the same given tire.

    Really stupidly low pressure is only good on really rocky terrain, ride the same setup on a road and it'll drag like hell squirm and spit you off on the first bend.

    Most of the drag is in the rear especially while climbing as there is next to no weight on the front try even a cheap Race King 2.2 on the rear, there really tall so great cush, role really fast and I ride 1 on the rear all year round.

    I've got a XKing 2.4 on the front currently I hit some very loose terrain and it lost it on 1 descent, couldn't steer just had to plow across some rough ground, I generally ride a HUGE Rubber Queen 2.4 on the front so the bigger and more agressive the better for me there.

  5. #5
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    i switched over to a Bont XDX 2.1 in the back...its 29x2.1, but its more like 2.0 it seems. Its much larger in diameter than the little albert. You can notice that its much closer to the seat tube, seems much wider too, even though the L.Albert says its 2.1, its more like 1.75...

    Most of the time, i run the front at 20psi (racing ralph, tubeless, 2.25) and the rear at about 23psi (little albert). Im going to run the Bont (tubed for now, tubeless as soon as my strip gets here, 2.1) at 20-21psi and hit a couple of trails. Mostly i ride over roots, rocks, with some mix of dry packed.

  6. #6
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    if you can understand what Turveyd writes, you're doing better than most of us.
    pay no attention to nominal tire sizes.
    i'm not sure you're asking the right question in your circumstance, but the bottom line if you take your question literally is: the taller the tire, the more efficiently it rolls (all else equal).
    in general, the larger (taller) and wider the tire, the more efficiently it rolls on any terrain. one big trade off is aerodynamic drag, which is generally a minor (negligible) factor in mountain bikes.
    the driver is tread deflection and the associated energy loss.
    also, the softer (sand) and rougher (gravelly, rocky) the terrain, the more lower pressure benefits you in efficiency (rolling resistance).
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  7. #7
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    Thanks MF, thats what i was wondering.

  8. #8
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    What MF says is true, all things equal, but remember than tire construction matters too. A tire that is taller than another but at the same width will have a thicker tread to accomplish that, and that thicker tread will likely lead to more rolling resistance, not less.

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