Tires: Volume vs weight

Discuss light weight issues concerning mountain bikes & parts.

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jazclrint
Posts: 45
Joined: Sat Feb 06, 2010 10:06 am

by jazclrint

Hello. Quick question. I have been running (26X)2.25 tires for the past two years or so because everyone say they are better, and the less rolling resistance and "float" argument makes sense. But 2.25 tires come at a pretty good weight penalty. Should I go back to 2.1s? I am 230lbs at 6'2" if that effects anything and the local trails are a very up and down. The climbs aren't long, but at good grades. I have been running more and more aggressive treads so moved from Rocket Rons EVOs to folding CST Heathens, and am now trying a set of cheap and heavy Nobby Nic (Performance compound and wire bead) take offs. I've only one ride and they are an adjustment, but the turns are so tight on the local trails that I am loving how much grip they have at full lean. A 2.1 Evo TL-ready is listed at 475g vs 545g for the same 2.25 version. I usually run 30-32psi front and +3psi in the rear.

Thoughts? Suggestions? Thanks.

by Weenie


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jooo
Posts: 1510
Joined: Wed Feb 02, 2011 3:48 am

by jooo

What rims are you using?

jazclrint
Posts: 45
Joined: Sat Feb 06, 2010 10:06 am

by jazclrint

Fulcrum Red Metal 0 (rim brake).

jooo
Posts: 1510
Joined: Wed Feb 02, 2011 3:48 am

by jooo

Inner rim width plays a big part in tyre volume so that's why I asked. I was going to suggest building/borrowing/trialing some wheels with wide rims to test out the different tyres for yourself but unfortunately rim brakes complicate that an awful lot these days.

jazclrint
Posts: 45
Joined: Sat Feb 06, 2010 10:06 am

by jazclrint

I have really nice wheels and would rather find what works best for them. But I think the general idea of volume vs weight is pretty interesting. I've always heard wider is better, but I just wanted to check that was actually the case.

raganwald
Posts: 31
Joined: Fri Mar 11, 2011 1:29 pm

by raganwald

jazclrint wrote:HA 2.1 Evo TL-ready is listed at 475g vs 545g for the same 2.25 version. I usually run 30-32psi front and +3psi in the rear.


Try this: instead of thinking about widths, think about volumes. The 2.25" is much higher volume, and that means you can run a lower tire pressure and get the same support. The lower pressure gives you a bigger contact patch and better surface conformance, and that gives you better traction and lower rolling resistance.

This only works if you actually run lower pressures, and 32psi is not low pressure, even at 230lbs. Try lowering your tire pressure. I'd start at 24psi and go from there. If you're running tubes, convert to tubeless and see if you can get pressures down to 20psi in front. Once you're using the 2.25 to its full potential, you can then consider whether the weight savings of a 2.1 is worth going back to 30+ psi.

Many people will tell you that once you've gotten your pressures down low, you'll never want to go low-volume/medium-pressure again. If I had permission to spend your retirement funds, I'd get you wide rims and put a lightweight 2.4 on the front like the Schwalbe Rocket Ron.

jazclrint
Posts: 45
Joined: Sat Feb 06, 2010 10:06 am

by jazclrint

Wow. That is low. I am already running tubeless. I had a set of RoRos in 2.25 before and less than 30 just didn't feel right, and I's get cuts in the center of the tread. But I'll give it a go as these Nics were free and I have a back up set of tires.

by Weenie


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