Tyre width

[eddy]

There have been a number of polls on “best” MTB tyre combinations, but I have not seen much on the effect of tyre width.

 

Taking, for example a folding Crossmark LUST tyre, what is the difference between 26x2.1 vs. 26x2.25 ?

 

With its greater volume, does the bigger tyre provide better grip or a more comfortable ride than the narrower one?

 

Is the narrower tyre significantly lighter or does it roll faster that the 2.25 ?

 

Can you run one of them at lower pressures ?

 

In short, what would determine the choice you make and why?

[LazyTrailRider]

It all comes down to how and where you ride. I've ridden all kinds of tyres in all kinds of sizes (from 1.2 slicks to 2.7 DH monsters), and they all have their place.

 

Bigger tires (2.2 and up) can be run at lower pressures because of their volume, and subsequently can give a softer ride. Obviously, there's an inverse relationship between speed and comfort as far as cushioning is concerned, in most instance. Please note that I said *in most instances*... The rougher the terrain gets, the bigger advantage fatter tyres have; it's been proven that lower pressures actually equal reduced rolling resistance over rough terrain, even though this is counter-intuitive and definitely not the case on smoother terrain. Thus, you need to determine what your average riding terrain looks like. If you ride predominantly on smooth(ish) hardpack and dirt roads (like you'll typically find on most races except the real provincial/national XC ones), you'll find that thinner tyres will be faster, albeit with a bit more vibration. If you're in good racing shape, you'll be able to handle the harsher ride and squeeze more speed out, but it's not all that much fun in comfort terms. Fatter tyres will slow you down a bit, but you'll definitely enjoy the ride more. If you ride mostly rough, rutted, rocky terrain, fatter tyres will in most instances be faster to start off with, regardless of your fitness level, because they'll roll smoother. Obviously, they'll give you more control and confidence as well.

 

My advice if you have to pick a set to start off with and you don't know: go fatter. You can always increase the pressure of a set of 2.2 tyres to make them roll faster if you find they're too slow. On a set of semi-bald 1.9s, there isn't much you can do if you find they're too harsh to start off with.

 

Hope that helps!

[Wernervdmerwe]

I agree with Martin - well explained.

If you want more explanations and results-based:

http://www.mckramppi.com/en/bike04rengas/Bike2004rengasanalyysi.htm

[Wernervdmerwe]

Ah - and some local experiments: http://www.mtbonline.co.za/info/mtb-tyre-rolling-resistance.htm

[eddy]

Ah - and some local experiments: http://www.mtbonline.co.za/info/mtb-tyre-rolling-resistance.htm

 

 

Thank you very much Martin and Werner, very useful.

 

But I should have read this before Crater Cruise

 

I seem to have made all the mistakes: narrow, hard tackies on the sinkplaat. No wonder I was so unhappy

 

Thanks to you, my next set will be fatter and softer

 

 

.

Edited December 20, 2010 by eddy

[MattyG]

wider tyres makes your bike look that much more sexy and also makes your head bigger by that much..so its win win