Rainy season brake noise recommendations?

[walkingman57]

Hi Folks, I'm riding an HT1000, which I love. It's strictly a commuter and a car replacer in my book. We've solidly entered the Seattle rainy season and have a question about wet rotor brake noise. When riding in the rain, my stock Magura MT5e brakes make an ungodly howl if I grab onto them too hard. To a large extent, I can avoid the howl if I feather well in advance to get the rotors heated up and "squeegee'd" off, but if I have to stop quickly, they make a ton of noise. Does anybody have any recommendations for minimizing or eliminating brake howl?

Thanks for any thoughts!

Steve W. in Seattle

 

[Ben J]

Ha, I was also riding in the Seattle area yesterday. Went a long stretch without needing brakes, then had to check up as I crossed a T intersection and at least the horrific squeal got all the drivers to look at me!

 

[fooferdoggie]

some combos are worse then others. my trek was not bad till I put magura rotors and maybe the ceramic pads now its horrible in the rain.

 

[m@Robertson]

I use MT5e's and I know exactly what you're experiencing. Here's the thing: There's nothing you can do about it.

What you are hearing is your brake rotors where the pad material bedded onto them has been washed away. Thats just what happens in the wet. The only fix is to re-bed them, which typically means you live with it until the day after the storm when water is not splashing onto them. The first chance you get, you go thru at least a limited bedding process, and repeat it on any downhill stretch along your route. Or you just ride normally and they cure themselves more slowly.

You can fudge this a little with gentle brake application that dries the rotors and does a bare-bones pad material deposit, but you've already figured this out. Plus it'll be gone as soon as more water re-soaks the rotors.

I am using Tektro downhill rotors so its not a Magura rotor thing.

 

[Ben J]

What you are hearing is your brake rotors where the pad material bedded onto them has been washed away.

Really? In that case you'd have to re-bed your brakes every time you hose down the bike. And to actually remove that material (if you did a bad job of bedding in the first place) people advocate things like sandpaper.

I think it's just the brakes gripping and then slipping repeatedly (due to moisture). If you keep using your brakes the heat will dry the rotors, though.

 

[m@Robertson]

People who do sandpaper are doing it wrong. You resurface auto rotors when they are grooved to prevent excessive pad wear on fresh pads, which is pretty difficult to do on a bicycle at all. Doing things like roughening the rotor surface or taking sandpaper to roughen brake pads (assuming the pads are not genuinely glazed) will not address the real cause of the problem, which is why so many people report squeal coming back again and again.

Your hosing the bike example seems to make sense but only at first blush: Spraying the bike with water is not the same as scrubbing wet rotors (hard!) with wet pads. That scrubbing is what cleans them off.

But you are correct the noise is the brakes gripping and slipping. But that behavior is caused by the loss of bedding material. Its not just the wetness of the surface. My brakes still squeal like banshees after a rain ride, the next day when everything is dry. A quickee 2-wheel-at-a-time bedding very nearly solves the problem by the bottom of the first (steep) hill. If I didn't have a steep hill right outside my doorstep I'd have to do it the long way.

How Do I Bed My Brakes?

Brake bedding is something almost nobody does and everybody should. Its a requirement on performance cars taken to the race track. Its the same procedure for any type of vehicle.

talesontwowheels.com

 

[fooferdoggie]

I think putting on metallic pads would help but I dont want to spend that much as the ceramics are pretty new.

 

[pete H]

Watching the Tour De France this year, all the pro cycling team bikes were squealing very loudly on wet downhills. If those guys with their experience and cash cant solve the problem we have no chance

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[walkingman57]

Thanks for all your thoughts!

Ha, I was also riding in the Seattle area yesterday. Went a long stretch without needing brakes, then had to check up as I crossed a T intersection and at least the horrific squeal got all the drivers to look at me!

You're right, it's a real attention getter!

 

[walkingman57]

I hadn't ridden for a couple of weeks until yesterday and my ride was in barely sprinkling mist, so it wasn't like I had ridden through a downpour to fully drench the rotors. I guess I just need to keep working on my braking technique.

 

[walkingman57]

...or just lock 'em up and whip skid!

 

[Ben J]

Watching the Tour De France this year, all the pro cycling team bikes were squealing very loudly on wet downhills. If those guys with their experience and cash cant solve the problem we have no chance

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Not necessarily. If there was a pad material that squealed less at the cost of some performance they wouldn't choose it for the Tour.