25 vs 23mm tyres

Jane

So what's the verdict on using 25mm tyres for racing?

There was a lot of talk last year about better rolling resistance, comfort and aerodynamics than 23s ... and the need to experiment with lower tyre pressures.

Are 25s making you go faster? And more to the point, will they make me go faster?

Nathaniel Rosa

25mm changed my life. Way better for descending (they are much more round - the continental gp4000sII's are what you should be looking at), markedly more comfortable (I can't believe how I put up with 23mms) and also looks better. The science (and a lot of it) says it's faster. I'm not fast enough to say either way, really, but I can tell you it is not slower.








also, I normally ride at 97-98psi f+r, but for the chaingang I tried running 93psi (both front and rear) and this was also a revelation - very very very velvety ride, but did feel very different - a bit floppy - but worth it for the extra smoothness... Will keep experimenting with that.



ps having done a lot of reading and asking my friends about the aero benefit - that really only comes in to play in conjunction with expensive wheels (25mm rim width as opposed to the skinny ones must of us ride)

Vic

The wider width rims are coming in on more budget priced wheels now.
My new Fulcrum Racing 7s that I've ridden with Conti GP 4 Seasons 25mm tyres this winter are specifically sized to work well with 25mms and only cost me about £100. Run at 90psi instead of my usual 100psi and really comfortable, better grip and apparently less likely to puncture too.

phil k

23mm.....120psi....it's the future

Stef

or if you cant make your mind up.. vittoria do a 24 mm pave
best of both worlds!

wilburtrump

Depends how wide he rim of your wheel is. Eg, Zondas have a narrow rim so make 25s bulbous and 27s impossible to use. Bontrager RLs have a wider rim so 25s come up with a similar profile to 23s on a more narrow rim. I train on 25mm paves on Easton slx wheels that have wider rims and they feel fine and are comfy to ride on, I race on bontrager Aeolus 5s which also have wide rims and run 23mm corsa CXs on. They also feel fine and are comfortable to ride on.

Not the most helpful of posts, I know...

Think it's just a trend thing more than anything else. You know how roadies work!

Sirlez

25mm - can't believe how much difference 2mm can make.. evidently sized does matter! Seriously, would not go back to 23's

geoffg

stef is right. 24mm pave vittorias fit zondas and all rims nicely. v.smooth and almost puncture proof.90-100psi fine. depends on weather

Andrew R

I have 2 x 25mm GP2000 S II available - 1 brand new in box and 1 slightly used and with slight rubbing on the sidewall (fitted to my summer bike then realised didn't have the clearance)

Will swap for 1 x 23mm GP 2000 S II

Cheers

Andrew