Re: Suspension losses

cyclintom <cyclintom@yahoo.com> wrote:

On Fri Jun 20 20:43:18 2025 Roger Merriman  wrote:

 
Who is saying they should ride 40mm tyres?
 
I?ve seen some reviews of 40mm road tyres which broadly comes down to
comfortable but almost certainly slower than 28/32 though non racers may
well make that choice.
 
Not seen anyone claiming 40mm tyres should be ridden quite apart from
anything else relatively few road bikes will fit 40mm.

 
 
 
 
I most certainly have not tried this since none of my bikes would mount
tires that wide but CyclingNews does recommend it.
 
https://www.cyclingnews.com/features/lab-tested-40mm-road-tyres-are-faster-for-nearly-everyone-and-heres-why/

They are again using the silverstone rig, ie cobbled and non cobbled drum,
and noted that on smooth tarmac rolling resistance was negligible, but
wider was less aerodynamic which is kinda obvious, and the conclusion is
that road bikes probably should be aiming at the 30/40mm space for ride
feel/handling reasons than speed.

Ie the article doesn’t say what you think it does if one looks beyond the
headline which is designed to hook one in.

 
Now I surely was surprised at the increase in average speed using 32 mm
tires (using very slow Gatorskins Hardshells) and also a very noticeable
increase in comfort and another advantage is that they roll right over
pavement cracks of quite a large size. You don't have to swerve to try
and cross at a closer to right angle.
 
But if you look at the rolling resistance site:
 
Most of the lowest rolling resistance tests are on 25 mm tires.
 
The rolling resistance tests need to be greatly changed since it does not
have "bumps" of the same size as those on open roads.
 
I had a gravel bike with 38 mm tires and I road with the group on a 37
mile ride with 3700 feet of climbing. Now these were gravel tires which
were semi-knobbies. But I had no trouble keeping up with the fast group.
(well except for a couple of 17 year old twins.)
 
The new bikes such as the Time Sylon has room to fit really fat tires.
 
 
 

Roger Merriman