Tire pressures in wet weather


Feb 3, 2017
I use the guide on the dorky pants site for figuring optimum tire pressure for my tires.

I was just wondering if there was any kind of tire pressure reduction guidelines for wet conditions. I know that there's a lot of different variables to consider, but what would be a good starting point to help get better grip when it's wet outside? Do you even worry about it?
For training? I never adjust PSI for wet conditions except for those very rare times when the group is hammering.

For racing in the wet (not just damp) 10 PSI minimum drop in PSI even with rain tires. There were many times I lowered them 20 PSI.
I've found that a 10 psi dropped did enhance my tires adhesion in wet vs running them at my usual pressure, and any website I've been on have said 15 to 10 psi drop is good for wet. If I started a ride and it was dry then a surprise storm comes in and the roads get soaked, I don't reduce my pressure for that, because about 15 minutes after the storm is gone the roads start to dry up and I don't want have to pump my tires back up with a mini pump! I only reduce it if I know I'm going to start the ride in rain and it's going to rain quite a bit during the ride.

Here is quite a little essay on all of this mumbo jumbo: http://www.velonews.com/2014/05/bik...technical-faq-tire-grip-wet-conditions_328827
I don't ever worry about it but it makes sense. Probably because I have never thought about it. :D

But I will say I did a 20 mile, 5,000 ft climb then got caught in and unexpected heavy downpour for the entire 20 mile descent with switchbacks. Didn't think to deflate the tires at all but never once did I lose traction on the heavily rain covered road. AND It was pouring rivers across the road the entire way. :eek:

I do avoid painted lines when it's wet but never had a problem not adjusting tire pressure. :cool:
I do avoid painted lines when it's wet but never had a problem not adjusting tire pressure.

It's probably only mandatory when going most ricky tick...racing in the rain is always a **** shoot. I used to run a pair o Clement or Vittoria rain tires and ride as carefully and smoothly as possible. Hanging off and keeping the bike as vertical as possible. Even when the skid demon smiled upon me there was always some guy too brave or too little experience or bullet proof that over cooked it in front of me. 2 riders up. 20 riders up. Sometimes the gods just pull your number. That's racing.

For cruising down a mountain in the rain just lay on some more brake and as the saying goes: Motor gently through the grease mud, for there lurks the skid demon!

No need to drop PSI in that case.

Now...if you're just headed out into an all day soaker and your training schedule calls for 40 miles at 250 Watts...drop the pressure and watch out for pot holes, offset bridge seams RR tracks and if you come across a steel deck cheese grater bridge...walk the damned bike across!
I switched to tubeless this year and run about 10-15 lbs less than when I ran tubed tires. Cushy and sticky and still very free rolling. Got caught in the rain the other day and sprinted home while taking some turns at a good clip. Felt really secure. Consider that option in the future but in the meantime, drop a couple of lbs and keep pedaling.
Be it winter, summer or rainy season, tire pressure plays an important role both for driver and the tire itself. It not only decides the overall life span of a tire but also the safety of the driver as well. As per a standard rule, it is necessary to get the tire pressure checked up every now and then in case you really want your tire to perform as per your expectations.

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