25c tyres pressure sluggish

cbtmrt

I have read quite a lot of people say they run 700x25c tyres at about 90-100 psi. At that kind of pressure the bike feels really sluggish, as if I'm going into a headwind or the tyre's going down. I usually have to pump mine up to about 110-115psi so that it feels quick. Why is this?! I have Vittoria Rubinos, ride on mainly smooth backroads and weigh about 13 stone if that helps! Thanks

Mickyg88

I've just bought some 25c conti 4000s today, will be interested to hear what people say, my lbs recommended 85-90 front and 95-100 rear.

hodge68

Recently changed to conti gators 25x700 from 23x700, run them at 95 were as the 23 ran at 110. If anything my Ridley feels faster and so much more comfortable.

Gizmodo

From what I've read the general recommendation is to run them about 5psi lower than your 23mm tires. This chart is what I normally base mine on http://www.bikequarterly.com/images/TireDrop.pdf

You have to work out your weight + your bike and all the bits, then split the load 60% on the rear, 40% on the front.

I've been running 25mm for a while, 90psi front, 110psi rear (approx) and I'm just a few pounds lighter than you.

crankycrank

Different tyres require different pressures to suit each individual. Experiment to find what works best for you. Only advise to give is don't use pressure beyond the max recommended and too little pressure can cause potholes and such to damage the rim and tube.

EPO Delivery Man

Dont worry, ive had a set of Vittoria Rubinos and they do need pumping up more with pressure more than any other tyre i have used. If you check the carcass on them i think they can handle something ridiculous like 140psi, but obviously thats rock hard.

I have run mine at 100-110 on the VRs and 90-100 on anything else. It just seems to be the way of the VRs.

oldwelshman

cbtmrt wrote:

I have read quite a lot of people say they run 700x25c tyres at about 90-100 psi. At that kind of pressure the bike feels really sluggish, as if I'm going into a headwind or the tyre's going down. I usually have to pump mine up to about 110-115psi so that it feels quick. Why is this?! I have Vittoria Rubinos, ride on mainly smooth backroads and weigh about 13 stone if that helps! Thanks

Its in your mind, may feel a bit different but certainly not faster, but if it makes you feel faster great There is no performance benefit.

marcusww

Just bought some 25 gatorskins and find that 115 on the back and 105 on the front is good for me at 16 stone. Higher than that seems harder but no faster to me. Anything less is sluggish.

declan1

I'm 11 stone and I run 25's at 110 front 115 rear. I find it pretty comfortable and as fast if not faster than 23's.

Sprool

I have also recently changed from Conti Ultra 23's to Conti GP4000s 25's, on the 23's i ran 105 front, 110 rear. With the 25's I'm running 90 front and 95 rear. They feel smoother, more comfy, less skittish and according to Strava a little bit quicker as well as feeling like they are more solidly planted to the rougher road surfaces. I weigh about 12- 3/4st.

wishitwasallflat

Conti GP 4000Ss 25s for me (replaced Open Pave 24s) I run them at 120 rear and 100 front (if I followed 15% drop chart I would need crazy rear pressure @ 19stone !!) - feels good to me.