bonsai171

Last night I did one of my regular loops that was around 35 miles. Got stuck in some huge downpours, and my 105 rim brakes were basically useless. Had to squeeze the brakes as hard as possible to get any sort of braking. In dry weather, it works really well. What can I do to improve braking in the rain? There wasn't even rain in the forecast, so it's not like I could have avoided it.

Dave

WhyFi

Get a bike with disc brakes?

bonsai171

Well there is that. I have a gravel bike with disc brakes I could use, but it's not as fast as my roadie. Was hoping maybe there's a brake pad better for rain use? Currently using 105 pads.

Dave

terrymorse 

Koolstop salmon pads. Best pads for wet conditions.

Kool Stop International - High Performance Bicycle Brake Pads Since 1977

bonsai171

Thanks, I'll have to try that.

Chuck M 

When I ride my rim brake bikes in wet conditions, I anticipate poor performance so I slow down a bit and I give them a couple of pumps to squeegee off some water. And I know people think disks are the beginning of the end of bicycles as we know them, but I love my disk brake bike.

79pmooney

Yes. Even their non-salmon pads are better than most. And there's the old trick - ride with your brakes lightly touching the rim. You've probably noticed the first rim rotation after you hit the brake, not much happens. Well, you can be doing that first rotation as you ride so as when it's time to brake, you've done that first rotation.

Also there is the lesson I heard when I started racing may years ago that still applies. When the going gets iffy, ride the drops. In the rain, I find I have far more braking strength from the dropouts than from the brake hoods. I was told to make my bikes fully rideable for long stretches in the dropouts and I still do that. From the drops I can squeeze the levers right to the handlebars (if that can happen with the caliper flex, cable/housing stretch and setup.)

Iride01 

How old are your 105 brakes? Are they from vintage days? Then yes they are crap compared to other newer stuff. However the 105 5800 double pivot brakes I had never let me down in the rain. Sure there was that "oh ****" moment when you first put them on to stop, but after scrubbing off the wet, releasing the brakes then re-engaging them they were almost as good as when dry for me.

Perhaps you just need new pads if yours are several years old and have been in harsh environment.

zandoval 

With wet weather rim brakes just don't really work. Slow down or just get off the road and wait it out. Of course you can always take this attitude...



As to the OP: I got stuck in some heavy drizzle once. Only a few miles from home I decided to ride it in. There was just one small down hill four way intersection on the return. RATS... half way into the intersection I had no brakes! Of course I was ridding and old bike with hard pads on Universal side pulls with steel rims. And of course there were cars at the base of the hill. At the last minute I laid my bike down on the left side and used my pedal to dig into the asphalt and slow. The only injury suffered was a bent cottered crank arm and a pedal. I don't know if this would work on a modern day bike, but then again they have disks. I should have walked it in...

koala logs

Cut grooves in the brake pads. The grooves must be parallel to the brake pads / rims.

What the groove does is reduce contact patch area of the brake pad with the rim. The smaller contact patch increases contact patch pressure (obviously) which reduces chance of the brake pad "hydroplaning" on the wet rim.

This will allow the brake pad to grip the rim the first time. No special technique needed. The only side effect of this mod is your brake pad will wear a lot faster due to the much smaller contact patch.

This is the same reason why disc brake works in the wet is because of high contact pressure not because the disc rotor is so hot, it's always dry, nope. A disc brake still grips well even if the rotor is cold and wet.

The holes in a disc rotor isn't for improving grip in the wet but for venting hot gas during long descents. Car disc rotors often don't have holes in them but they will work so well even in the wet. It's all about contact pressure when dealing with wet conditions. You can also do the same with rim brakes by cutting grooves on the brake pads.

Chuck M 

Buy good pads and understand how to brake in the rain or Dremel your pads? I've been doing this wrong for 50 years.

indyfabz

Good lord. How am I not dead then having ridden fully loaded bikes down mountains in rain, sleet and snow, among other things, with only rim brakes?

Koyote

No. Just no.

Mojo31

Pure luck.

LarrySellerz

I had a bike where the rim brakes worked fine in normal conditions but had no power in the rain, was pretty weird. I think its because the pads were so old, it was a department store road bike from the 70s.

indyfabz

This one time at band camp….

indyfabz

Wasn’t it ol’ cubewheels who was known for giving dangerous advice? Things that make you go “Hmmmm?”

philbob57

not weird at all with steel rims.

aliasfox

Had something similar with my Bianchi from 2004, equipped with Ultegra 6500.

The NYC 5Boro Bike Tour in (I think) 2017 was done in a constant heavy drizzle, and my brakes were useless. Fresh salmon Koolstop pads weren't especially useful, even toed in to squeegee off the water. It took me a while to realize that my old cables (original since I purchased the bike in 2005) weren't doing me any favors, and had them redone. BAM - fresh cables and housing = much reduced friction, solid braking in dry, very adequate in wet.

If your cables are more than a few seasons old, it may be worth getting new ones. Dirt/grit/sand/moisture gets into the housing, and friction isn't far behind.

New brake pads could be good as well, but you could also try taking a bit of sandpaper to the surface of your current pads - don't sand down the pads, but rough up the surface just a bit, especially if the pads are looking glossy/glazed.

Lastly, it may be worth scrubbing down your rims with dish soap and an old dish scrubber every so often. After years of close contact with road grime and mechanical lubricants, they're bound to have picked up stuff. I'd only recommend this for alloy rims - not sure what the best way to clean carbon rims would be.

terrymorse 

I've been using ammonia and water on a soft cloth for my carbon rims for many years.

It seems to do the job. The rims are going strong, with no sign of braking surface wear.

Zaskar

I ride disc and rim brake bikes. Yeah, the discs stop great. But, the rim brakes work well too - even with carbon wheels. In the rain, they're no where near as well as the discs. But they are definitely fine.

There are two things you have to pay attention to...
1. Get the right compound - I like SwissStop Prince pads and the Reynolds pads (for Reynolds wheels)
2. Pad maintenance. Seriously. It's a thing. Pads get glazed - a hard, slick surface. Check them occasionally. I use a rat tail (round) file and scuff them at about 45 degree angle. Don't reshape the pad - just get rid of that glaze.

^that^ should help... until all your bikes are disc.

big john

merlinextraligh

With good pads rim brakes work fine in the rain. I just did some 20% descents in the rain in Western NC with no problems
​​​as others have alluded, “squeeging
“ the water off is key. You just have to realize that you’re going to need to evacuate some water from the rim before you get much braking force.

So in wet, hilly conditions you need to anticipate the need to brake, and lightly apply the brakes to move the water before you actually need to brake.

veganbikes

I would use SwissStop pads with the BXP compound ideally but KoolStop Salmons are also a great choice or one of their dual or triple compound pads. If it has "stop" in the name that is a good sign you are getting good pads.

Don't start cutting up your brake pads please.

rsbob 

Before the age of disc popularity, a friend and I did a 2000’ decent averaging 6% on a racing tandem in an unforeseen downpour. Unfortunately we only had side pull brakes with Cool Stop red pads and no drag brake. By the time we finally got down after being lashed with rain the pads were ground down to 1/8” from the metal pins. The grit on the roadway also did a number on the rims. Hand cramps and shivering were a bonus. No commentary on how good or how bad pads are, just my adventure.

I now have two bikes with discs and two with pads. Guess which are ridden in the rain.