How to Stop Bike on Descent if Brakes Fail?
#51
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One data point - I rode down Mt Washington in 1976. Flatted 3/4s of the way down from over-inflation from a very hot rim. (Melted the glue for my sewups. I burned my fingers when I touched the rim. Brakes still worked fine.) Now I had been doing what you are not supposed to do with either rim or disc brakes; ridden them near continuously going down 3000' of 11+% average grade. (Gravel surface and many corners you weren't going to make going fast.)
Yes, I should have been using a glue that set up harder and wouldn't melt. If Mt Washington had been a regular ride instead of once in a lifetime, I would have. But otherwise, those no-name centerpull caliper brakes did just fine despite dispelling a very large amount of energy as witnessed by my rim temperature. (Aluminum with its excellent heat dissipation, not carbon fiber.) Using discs going down that hill without stopping? I'd let someone who weighed more than me with the same brakes and fluids go first and call me from the bottom. (Actually I probably wouldn't. I was young and stupid.)
Ben
#52
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Can't happen; everybody knows the only way to stop a bike that fast is with unicorn-hoof pads gripping magic mithril platters, actuated by pressurized virgin tears. It's why no cyclist has ever survived a downhill with rim brakes.
#53
Cycleway town
There's a third option. Use good cable operated caliper rim brakes. Maintenance is simple. Visual checks are simple,. The only hidden portion of the entire system is portions of the cable. Replacing cables is easy. (Maybe not on some "brifters". I can't speak there, having never ridden them. Brifters always struck me as a bad idea on several fronts.) Both caliper brakes failing completely is a very rare occurrence. I've heard of maybe a few cases in my lifetime whereas I've heard as many in the past 20 years with a vastly smaller number of disc setups.
One data point - I rode down Mt Washington in 1976. Flatted 3/4s of the way down from over-inflation from a very hot rim. (Melted the glue for my sewups. I burned my fingers when I touched the rim. Brakes still worked fine.) Now I had been doing what you are not supposed to do with either rim or disc brakes; ridden them near continuously going down 3000' of 11+% average grade. (Gravel surface and many corners you weren't going to make going fast.)
Yes, I should have been using a glue that set up harder and wouldn't melt. If Mt Washington had been a regular ride instead of once in a lifetime, I would have. But otherwise, those no-name centerpull caliper brakes did just fine despite dispelling a very large amount of energy as witnessed by my rim temperature. (Aluminum with its excellent heat dissipation, not carbon fiber.) Using discs going down that hill without stopping? I'd let someone who weighed more than me with the same brakes and fluids go first and call me from the bottom. (Actually I probably wouldn't. I was young and stupid.)
Ben
One data point - I rode down Mt Washington in 1976. Flatted 3/4s of the way down from over-inflation from a very hot rim. (Melted the glue for my sewups. I burned my fingers when I touched the rim. Brakes still worked fine.) Now I had been doing what you are not supposed to do with either rim or disc brakes; ridden them near continuously going down 3000' of 11+% average grade. (Gravel surface and many corners you weren't going to make going fast.)
Yes, I should have been using a glue that set up harder and wouldn't melt. If Mt Washington had been a regular ride instead of once in a lifetime, I would have. But otherwise, those no-name centerpull caliper brakes did just fine despite dispelling a very large amount of energy as witnessed by my rim temperature. (Aluminum with its excellent heat dissipation, not carbon fiber.) Using discs going down that hill without stopping? I'd let someone who weighed more than me with the same brakes and fluids go first and call me from the bottom. (Actually I probably wouldn't. I was young and stupid.)
Ben
A hill is no match for a motor. The best rim brakes i've had are the ones on my 80cc petrol Ellswick. All over-engineered steel with proper rubber bricks for brake blocks, it's an over-the-handlebars job if i go too firm at any speed and they keep coming back for more. Unless it's wet. In which case, they're useless.
Brakes notably affected by wet weather are not acceptable to me.
My e-bike is much faster than the Ellswick. And much heavier. And i use it on footpaths so it's constant braking/accelerating across town. It's huge floating discs and twin-pot calipers are absolutely in another world compared to the Ellswick's rim brakes or any other. And despite being used every few seconds for miles, they're utterly consistent.
The only thing worse than the feeling of the cable stretching is the knowledge that the cable is crushed at the end... it's a bodge job next to hydros, feels it and works like it.
Last edited by MikeyMK; 02-13-18 at 09:32 PM.
#54
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Organic pads are said to fade more readily than the metal sintered ones. I use them because they are less prone to squealing like a juicy, avid pig, and give better modulation. Ain't never been a problem.
#55
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So, you were rolling so very slowly down a hill that you glazed your pads and smelled spray paint. Got it.
-mr. bill
-mr. bill
Last edited by mr_bill; 02-14-18 at 07:14 AM.
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foot on the back wheel
both feet on the ground (barely works)
slide out the back (bmx style)
but in OP's case, hold on to your buddy and let him brake
#58
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several 2 and a 9 month bike tour , no braking problems .. I'm a Mechanic, Jim. (Scottish accent)
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I weighted 260 pounds at the time that I descended a mountain with about 8 to 18% downhill slopes, switchbacks all the way, good tarmac making me gain up to 40, 50 MPH then braking hard for the next switchback. First time, halfway down, Avid Single Digit 7 calipers with CoolStop pads started burning. Litteraly set the pads on fire. It stinked terribly, braking was bad.
Another go at the mountain, this time bike with Shimano mid range hydraulics. After 3/4 of a way down, heavy brake fade, pads billowing smoke. Scratch one more off the list.
Then I equipped the first bike with mechanical disks Avid BB7, front disc 203, rear 180, sintered mettalic pads. Now, this setup I rode as hard as I could, bashing it itentionaly to the limit, I came down from the mountain with blue smoking rotors, the plastic around the setting knobs for pads were partially melted, BUT, brakes never ever once gave up. They roasted, spit out some smoke during the last part of the descent, rotors became dark blue from the heat, I rode them like a crazy man, picking up speed and braking heavily at the last moment. Me and bike and equipment was probably over 300 pounds.
In the end, they worked beautiful without any fade. I pushed them repeteadetly over the limit, and they performed. The same brakes are still on my bike (10 years later today) working as the day one. Need I say more? No messy liquid, no special tools, no worry about bubbles, they just work and work. They need a good firm push on the levers, but they stop me when needed, bar none. Always 100% reliable. And I still havent replaced that half melted plastic knob haha.
Another go at the mountain, this time bike with Shimano mid range hydraulics. After 3/4 of a way down, heavy brake fade, pads billowing smoke. Scratch one more off the list.
Then I equipped the first bike with mechanical disks Avid BB7, front disc 203, rear 180, sintered mettalic pads. Now, this setup I rode as hard as I could, bashing it itentionaly to the limit, I came down from the mountain with blue smoking rotors, the plastic around the setting knobs for pads were partially melted, BUT, brakes never ever once gave up. They roasted, spit out some smoke during the last part of the descent, rotors became dark blue from the heat, I rode them like a crazy man, picking up speed and braking heavily at the last moment. Me and bike and equipment was probably over 300 pounds.
In the end, they worked beautiful without any fade. I pushed them repeteadetly over the limit, and they performed. The same brakes are still on my bike (10 years later today) working as the day one. Need I say more? No messy liquid, no special tools, no worry about bubbles, they just work and work. They need a good firm push on the levers, but they stop me when needed, bar none. Always 100% reliable. And I still havent replaced that half melted plastic knob haha.