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From: Roger Merriman <roger@sarlet.com>
Newsgroups: rec.bicycles.tech
Subject: Re: Rolling Resistance
Date: 21 Jun 2025 08:08:50 GMT
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AMuzi <am@yellowjersey.org> wrote:
> On 6/20/2025 6:04 PM, Frank Krygowski wrote:
>> On 6/20/2025 4:34 PM, cyclintom wrote:
>>> If you scan the rolling resistance chart all of the lowest 
>>> rolling resistance is on 25 mm tires. What that implies is 
>>> that the drum is entirely out of sync with the real world 
>>> since wider tires with lower pressures are both faster and 
>>> less likely to puncture. It is time fore the rolling 
>>> resistance people to redesign their setups to have more 
>>> connection to reality. My speed after two weeks off of the 
>>> bike with 32 mm tires is half a mph faster than riding a 
>>> lot on 28's
>> 
>> I'm going to shock people by agreeing with you on one point. 
>> I do think the current test rigs for rolling resistance need 
>> serious improvement. I've mentioned that before.
>> 
> 
> +1
> A long time complaint here on RBT beginning with Mr Brandt 
> long ago.  Steel drum tests can be very accurately measured 
> but what they measure leaves a void between that and our 
> actual world.
> 
Particularly the small drums and smooth drums that
bicyclerollingresistance.com uses hence its data doesn’t correlate that
well to MTB tyres in particular.

Silverstone has a much bigger drum with all sorts of surfaces, that folks
like Dylan Johnson have used to test tyres (MTB) which has correlated with
his real world testing so is bit more faith in that drum and set up, but
even so that it’s a hugely simplified model of the world must be accounted
for plus is one’s goal just speed?

Certainly off road even if one wants to ride fast, a fast rolling tyre
isn’t always your friend, the Thunderburts which are light with out much
tread are popular as fast tyres be that Gravel or XC but they are very much
terrain specific!

Even in mid summer descending on the steep grassy slope off the top of the
mountain to my folks place, with those you’d be running wide on the turns
in any other season you’d not make the turn!

Roger Merriman