Tyre pressures in the winter time / wet the same or lower?

paulc33

Just wondering do people lower their tyre pressures slightly in the winter or wet conditions to aid better grip?

I'm running conti GP4000s I I's. I normally have the pressures at about 110-115 psi.

Went out this morning and it was a bit damp on the roads and found it a bit sketchy at times and it got me thinking should I lower the pressures slightly.

Or will that just mean more punctures....

keezx

Depends all on your tyre width, rims, weight, riding habits.
I'm allready very low, so don't lower anymore, but 110 PSI leaves some potential.
Lower 10 PSI and try.....

paulc33

I'm about 76/77kg. Tyres are 25mm on fulcrum racing 3's.

Maybe il try lowering a bit like you say to 100psi and see.

Strith

If you're on standard width rims this is a good starting point:
http://www.bikequarterly.com/images/TireDrop.pdf
I used to drop my pressures a few psi in the wet, but I cant be bothered anymore.

mrb123

Should be fine to run 80 front and 90 rear. That works for me at 79kg on 25mm tyres .

stueys

Gp4k aren't great in winter conditions though they are fab summer tyres. I swap over to 4seqsons at this time of year and find wet weather grip and puncture resistance much better

paulc33

Am trying to avoid buying another set of tyres. As bought the gp4000s for my Tarmac then swapped them with in a number of miles for s works tyres and love them. So thought I would try the gp4000s on my winter bike.
But keep reading reports the 4seasons are a much better winter tyre.

roger_merriman

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19755954#p19755954]paulc33[/url] wrote:

Am trying to avoid buying another set of tyres. As bought the gp4000s for my Tarmac then swapped them with in a number of miles for s works tyres and love them. So thought I would try the gp4000s on my winter bike.
But keep reading reports the 4seasons are a much better winter tyre.

If any thing the GP4000s should all thing equal be better grip than the 4seasons which are somewhere between the GP4000s and Gatorskins, IE a slightly harder compound rubber and more robust compared to the GP4000S.

To be honest I never found any road tyre to be terribly grippy on wet greasy Tarmac, too small a contact patch, with harder compounds and pressure.

DavidJB

200psi or gtfo

k-dog

110 seems high even in the summer. You probably want 95-100 - way more comfortable = faster.

I'd try 90ish this time of year. Should feel much better.

olake92

Running 25mm, 115psi is too high.

The conti website recommends 95psi for the 25mm gp4000 S II. I find their recommendations are usually spot on.

sungod

the gp4000s are fine for winter, especially 25mm, the compound is one of the grippiest there is, you can get tougher tyres but they may not be as good in the wet

you're not heavy, so as long as you avoid pot holes etc. you can run them at lower pressure without problems, 80-85 in the wet gives you some extra rubber on the road

stueys

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19756070#p19756070]roger merriman[/url] wrote:

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19755954#p19755954]paulc33[/url] wrote:

Am trying to avoid buying another set of tyres. As bought the gp4000s for my Tarmac then swapped them with in a number of miles for s works tyres and love them. So thought I would try the gp4000s on my winter bike.
But keep reading reports the 4seasons are a much better winter tyre.

If any thing the GP4000s should all thing equal be better grip than the 4seasons which are somewhere between the GP4000s and Gatorskins, IE a slightly harder compound rubber and more robust compared to the GP4000S.

To be honest I never found any road tyre to be terribly grippy on wet greasy Tarmac, too small a contact patch, with harder compounds and pressure.

I ride both, GP4S in winter and Gp4K in summer. Ridden both in very wet conditions and found the GP4K to be fine when the temp is up but not as grippy when the temp drops. I also find the GP4k to be a puncture magnet when it's wet. I find it worth swapping. To be honest if I could only have one tyre I would probably stick the GP4S on and keep it there, you pay a very small weight penalty for far superior puncture protection.

philbar72

gp4ks are thorn magnets... and they cut up more readily than the 4 seasons.

Schwalbe ones are vey good tyres, more grippy than 4000S and have equivalent or better puncture protection.

bernithebiker

When we run tours, we prepare the bikes for the clients in the morning, and pump the tyres to 100psi max.

It's always interesting to see them come down, ask for the pump and whack in another 10 or 20 psi. Completely unnecessary, but hey, if that's what they want....the customer is always right!

(If wet, personally I'd go for between 80 and 90 psi depending on your weight).