Re: fast tires

On 6/12/2025 12:38 PM, Mark J cleary wrote:

On 6/12/2025 7:19 AM, Roger Merriman wrote:

cyclintom <cyclintom@yahoo.com> wrote:

People seem to think that fast tires have low rolling resistance but that
is hardly the case In the rolling resistance tests 25 mm tires have lower
rolling resistance than 28's. And high pressure 23 mm lower still,
Remember that they claim that their setup has bumps etc to correct
rolling resistace for road conditions but that can't be the case.
>

Whose tests? Drum tests particularly one with smaller drums will give a
less realistic model of tarmac.
>

Vittoria Corsa is rated as lowest rolling resistance but in my experience
Michelin Pro5's are faster. Also I  find that setting pressure below the
Silca pressure calculator increases the speed if not taken to extremes.
>

Both are designed to be fast road tyres, so you’d expect fairly close
performance between brands. And road is much more homogeneous than gravel
or MTB
>

I find TPU innertubes to be unbelievably expensive and flat very easily.
I see no advantage to them. While Latex tubes do increase speed, they
have to be pumped up every ride. In cold weather I can ride a butyl tube
for a week before pumping them up again.
>

In my relatively short experience of TPU tubes, is that they offer same
amount of puncture resistance aka zero if it gets through the tyre, it’s
game over.
>
They do feel noticeably nicer vs Butyl tubes, are yes more expensive and
more tedious to fix, though that would depend on how many punctures someone
gets I used to get 1 every year or less. So it’s a £10 over a year at
worst.
>

Tubeless is nasty to work with. The tires are more expensive and harder to mount.

>
Absolutely can be, the ongoing maintenance is why I run it on one bike and
not all of them. While I’m a fan it’s not the best option 100% of the time.

>
The informaion we are being fed is lacking accuracy and incomplete
leaving you to have to experiment yourself.
>

As with life need to fact check and be sure one understands let alone that
for example tyre choices for example for my gravel bike each ride I do
would favour different tyre choices.
>
I’m fairly sure that for my uses bigger tyres into XC MTB sizes would
perform better for me most of the time.
>
Roger Merriman
>

 I ride faster on my 25mm road bike Conti GP5000
s on the rim brake Habanero. I ride slower on the 32MM Conti's I have on the disc brake Habby. I have no stats or ways to measure except how fast I ride on any given ride. Lately the fatter 32 mms seem to me to be a bit heavy and roll with more balancing require by me. I have no idea why.
 

It may have something to do with the road surface. One reason 32s can be faster than 25s is if the road surface is on the rough side. If you've been riding on new pavement lately, the 32's don't offer much advantage.
Of course inflation pressures have a lot to do with it. You might want to experiment with the pressures, and don't forget to consider that your gauge may be off too. The pump I keep in my car pump somehow become offset by 20 PSI with no warning. I should just toss it because I have three more floor pumps that are all good, I just have a real hard time throwing away usable cycling parts and equipment (Much to my wife's chagrin).
It sounds as if you're running the 32s somewhat underinflated. Put another 10 PSI in and see what you think.
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