Tyre width - 22? 23? 25?

What’s the prevailing thoughts here?

Is it 25mm now?

Got an 808 up front and a disc at the back

Whatever suits your wheels best, I’ve got 23 front and 25 rear because of rim shape

Am I going to have to try and find the spec for those wheels?

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Yeah man.
I’d go with 19mm up front, 21mm on the rear.
Get them up to 10bar.
And make sure your teeth are glued in properly :rofl:


105% innit?


28 min

Been talking about this lots recently.

We moan like duck about the roads and then use 23 mm tyres as there 0.0000045 more aero or some crap.
I did a ride on 28 mm tubs with 70 psi in 5 weeks ago, what a revelation.

I’ll be going go 4000”s 28 mm for the big day as they are considerably bigger than the 28 mm 5000”s

No idea why ?

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Does depend on the frame though. I use 23’s on my TT bike as the rear cutout is a bit snug for a 25. I do use one on a training wheel, but I’m not 100% certain it doesnt rub a fraction, so on raceday would rather be sure there’s no lost friction there.

On reflection, I’m not sure if playing with the horizonal drop out grub screw things might increase the clearance a little bit to make a 25mm a more obviously comfortable fit.


23 all the way

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I think you have to take road surface into account. 25cc seems to be a good sweet spot, certainly in the UK.

The smoother it is the narrower and/or higher pressure you can run.

This isn’t (only) about comfort. You want the tyre to deform over the bumps and ripples as this will give less resistance than one which is rock hard and knocks you all over the place.
If (to take it to its logical conclusion) you are on smooth boards on the track I presume they run very high pressures on narrow (ish) tyres.

Sorry to not be more specific. Lots about it on the marginal gains podcast.


& 110 psi min


Looks like i’ve been totally wasting my time on my 28s the past year or so then. I think i must have had the old fashioned ‘i’m on a road bike so pump to 100-110’ mantra in my head. Especially on the crumby lanes and surfaces we have around here. Maybe for all my general riding i should be dropping it down to 70-80 then!

Will do the same foe Mrs GB as well. I put 28s on her bike to help with comfort (she’s not interested in speed/racing), but i may have done her a disservice by still over inflating the tyres.

Everyday is a school day!


26 on the front - 85PSI
28 on the rear - 80PSI

Pressure based on this calculator SILCA Professional Pressure Calculator


How does that compare to the SRAM/Zipp one?



Had 60psi in my 28mm gp5000’s for the HOTNW. Going to lower to 55 next time out as I think it’s still on the hard side.
Did my NC500 trip on 32mm at 45psi.


The marginal gains podcast is done by Josh someone from SILCA, so probably the same theory behind it.

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I have an older argon e116, 25 is fine on the front.

The rear I’m in the same boat, I actually got a 28 to work up and down the street, but that’s with the wheel locked right at the end of the drop outs.

I’ll hopefully get 25 on it.

E119 should take 30 mm with a bit of fettle.

Just had a whirl and it suggests to go 70 (front 25) and 73 PSI (rear 28) :thinking: so quite a difference!

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Wow. That’s a big old difference!

Lol, I don’t even inflate my 23’s to that pressure! About 95ish … maybe 100 if it’s overseas and a good surface. My roadie has 25’s, and I’ll put 85-90 in those.

I did the same on my OH’s bike, and pump those up to about 80 initially, and then don’t touch them for weeks and weeks. There’s no way she’s attempting to pump them up, and I also can’t be bothered to keep checking them all the time. So I slightly over inflate initially, and then that way they’re good for ages.