Tyre pressures in wet/greasy conditions

grahamcp

Had a fall at the weekend whilst conering - I was conscious of the greasy conditions and was riding more slowly than usual because of that (it's a corner I often go round), but both wheels just seemed to disappear beneath me at the same time.

Had several hours in A&E to mull over what went wrong and my conclusion was tyre pressures - had fixed a rear puncture the day before and had topped both up with the track pump to just over 100psi.

In retrospect I think I may have been better to have dropped them to around perhaps 85-90psi. But just wondering as to others thoughts on that - would you go lower/higher?

Cheers,
Graham.

PS. luckily no bones broken, but very sore hip, neck and thigh muscles.

reverendmark

Glad to hear you're alright.

I had the same problem last week - and I think I was running my pressures too high also. I've since been told 80-90psi is about right for the conditions.

JWSurrey

I rang the LBS, who reckoned that last week was about as slippery as it could get!
Glad to hear you're OK - An aquaintance smashed his hip to pieces last year.

I ride 25c which gives a bit of extra footprint (GP4000 with reflective sidewalls).
Generally 90psi, but sometimes a little lower - c.85.

Am on the cusp of putting the quill pedals back on with loose fitting toeclips, to avoid having a nasty clipped-in fall - which I managed on the side of a mountain in Vermont a few years back!

You've probably seen the posts about the best winter tyres.
The GP4000s don't get a particularly good rep. for winter riding, but there have been various recommendations for Michelin carbon Krylions.
One suggested Vittoria Paves.
I might, if I'm bored, try some Conti GP4 seasons. Given they're marketed at the same price point as the GP4000, I figure they must have better grip!

Lagavulin

I've got some 23mm Krylions and their sidewalls mention 113 as their max PSI. I've been using that despite the crap conditions as previously I'd tried runnign a few Spesh tyres at lower pressures with disastrous effects.

In my search for an new bike I've looked at Roubaix ( a current frontrunner for my £2 grand) and in C+ they mentioned running the Roubaix 25mm tyres down at 85-90 PSI. That seems ridiculously low.

rustychisel

25mm tyres at 85-90 PSI seems a good idea when conditions are treacherous; can't imagine why you'd find that ridiculous.

BTW, when you puncture on the road and have to use a little ole compact pump to inflate, remember to check tyre pressure when you get back home. Bet you find it closer to 85psi than over 100. Just sayin'.

Lagavulin

Perhaps not "ridiculous". That was a poor choice of words on my behalf.
It does seem a bit low though. I tend to to air on the side of caution nowadays after having a sodding awful batch of pinch punctures.

I've got a few mini-pumps and you're certainly right in saying that the pressures I can get into a tyre using those is poor. Infact a dead right arm later and I'd view 85PSI as a good effort. :oops:

However, I've never viewed the mini-pump as anything other than a lets get home tool and personally haven't ventured further from home unless a LBS/mate/relative or anyone with a track pump as a closer port of call.

rustychisel

understand, and apologies too, I jumped in a bit there. I commonly run Veloflex Pave at 120psi rear and 110psi front, but will drop it about 10 for rainy days (we don't have any here).
Love 'em too, but they're only 22c.
Have been using Vittoria Rubino Pro for the last coupla months, and have to say Vittoria are overated across the range. Rubinos are okay, but pretty dead and lifeless; that's part of the tradeoff I guess, but I note more than a few people say they're lethal in the wet. Think I might be in the market for GP4000s, perhaps the black chili model, otherwise it's back to the Veloflex for me, which are entirely predictable in either wet or dry, and sooooooo supple and smooth feeling.

carlstone

You can do whatever you want with your tyres, but hit a patch of diesel on wet roads and theres nothing you can do. I was sat at a set of temporary traffic lights in my car a couple of years ago, heard a screetch behind me and a car hit the car behind me and that was pushed in to me. When I got out of the car I could bearly stand up it was that slippery. Ridiculous.

simbil1

Ditto on the 25mm with around 90 psi front and 100 in the rear - the theory being I won't stay up if the front skids so keep it low but I may stay up if the rear starts to go and that will also give me feedback on how far I can push it. Also I do most of my braking on the front.

I think you are less likely to pinch flat with a 25mm tyre too.

Adamskii

I'm new to this forum but I've been riding for ten years.

I had a big off a couple of weeks ago due to the conditions. I got back on my bike today to find the roads were very slippery despite dropping my tyre pressures to 60psi. My knee is still healing so I really don't want another fall, just yet!

I use Continental Gator skins (25mm). Does anyone know of a more durable winter tyre or is that as good as it gets?

DaveyL

I use Spesh Armadillos in winter and I think they are brilliant.

simbil1

Adamskii wrote:

I'm new to this forum but I've been riding for ten years.

I had a big off a couple of weeks ago due to the conditions. I got back on my bike today to find the roads were very slippery despite dropping my tyre pressures to 60psi. My knee is still healing so I really don't want another fall, just yet!

I use Continental Gator skins (25mm). Does anyone know of a more durable winter tyre or is that as good as it gets?

I don't think Gator's are renowned for their grip - more for their puncture resistance. I run 25mm GP4000's and they seem pretty good in the grease though I don't know if they would last long if I road regularly through the winter.

Good luck with your knee.

Bronzie

DaveyL wrote:

I use Spesh Armadillos in winter and I think they are brilliant.

In terms of puncture resistance, yes.........................in terms of grip, nooooooooooooo! (splat)

JWSurrey

Adamskii wrote:

...Continental Gator skins (25mm). Does anyone know of a more durable winter tyre or is that as good as it gets?

GP4 Seasons get better press, and I think they have the same protection my GP4000s have - although annoyingly they don't have a reflective sidewall (available on the GP4000).
According to the blurb, the GP4 Season is optimised for wet weather riding.
Ran my GP4000S all last winter on wet gritty potholed roads round the local farms.

I do ensure I check the soft/adhesive rubber for stones etc. after each ride..... I piece of glass only once stuck in to the Vectran canvas, but luckily didn't pierce right through and cause a flat.

DaveyL

He did ask for durable!

jimwin

Bontrager Racelite hardcase for me. You can get them online and postage free from Pedal On in Hampshire.

They roll well and are as tough as old boots. Used to use them in the rain on all the flint laden roads around that county.

And they have strong sidewalls, unlike Conti's.

- Jim

Adamskii

Lots of choice for me to look at then, I'll pop down to Ribble later to see what they have. Thanks for your tips.

P.S. My confidence has gone, I'm even breaking on descents which I never usually do

simbil1

Try to relax and slowly build up your speed, your confidence will come back

pawlfreehub

As regards the original question, the "correct" pressure is also weight dependant so it varies, and I use less pressure in the front than rear tyre, does everyone?
Also if you consider that if hammering into a steep downhill hairpin braking hard will tend to unload the rear tyre, you can see that technique has a significant impact on grip.