On 7/31/2018 11:44 PM, James wrote:
On 01/08/18 12:32, Frank Krygowski wrote:
On 7/31/2018 11:00 AM, wrote:
On Friday, July 27, 2018 at 5:02:58 PM UTC-7, Frank Krygowski wrote:
On 7/27/2018 7:36 PM, Frank Krygowski wrote:
On 7/27/2018 3:13 PM, wrote:


I have a problem understanding what sort of riding you people are
doing. Joerg and I seem to ride in the same manner as does (or did)
Joy. 32 mm tires are for Cross or Gravel bikes. Why would you ride a
high rolling resistance tire on a commuter which operates in the
speed
regime where rolling resistance is the prime source of friction?

I'm not certain, but you seem to be implying that 25mm tires must roll
easier than _32mm_ tires. I don't believe that's the case.

https://road.cc/content/feature/1825...ch-wider-tyres



https://janheine.wordpress.com/2018/...es-are-slower/



https://www.schwalbetires.com/tech_i...ing_resistance

Sorry, I corrected my typo. "you seem to be implying that 25mm tires
must roll easier than _32mm_ tires."

Frank - of course there is a point of diminishing returns. The
pressure to support a rider gets lower and lower with increasing tire
width so at some point the amount of rubber on the road starts to
increase the rolling resistance.


Here's another Jan Heine article on the topic:
https://janheine.wordpress.com/2016/...ure-take-home/


A friend rode a fat bike for some distance (70-80km I think) over the
weekend.Â* He found it a real drag to pedal compared to his dual
suspension MTB.

Fatter tyres must be heavier and contribute more aerodynamic drag.

There must be a point at which the lower rolling resistance of wider
tyres is outweighed by the increased weight and aerodynamic drag.

Yes, and I think the point moves or varies depending on several factors,
for example average speed, roughness of the road or trail surface, mass
of the rider, construction of the tire, etc.

But on our cracked, potholed and patched roads, I know riders who are
still running 120 to 160 psi on 19mm or 21mm tires. I'm positive they're
mistaken in their belief that those are faster.


--
- Frank Krygowski