Brakes got weak in the garage

[spokewrench]

I've had two e-bikes whose mechanical brakes would stop me in 20 feet from 20 mph, like a modern car. In fact, they'd do it with the front brake alone. I couldn't have stopped so short without risers for the handlebars (to keep me from being thrown over them) and layback posts (to move my weight back).

For 8 months I've had an e-bike with hydraulic brakes. My mechanical brakes would stop me just as short, but the hydraulic brakes are maintenance free.

I've ridden my bike with mechanical brakes only 112 miles since I got the new one 8 months ago. Yesterday, I found that the coefficient of friction between pads and rotors had gone way down. Bedding helped: get up to 20 mph, heat one brake by using it to slow rapidly but not stop, and repeat. They're better but need more bedding.

I suppose oxidation reduced the coefficient of friction as the bike sat in the garage. With hydraulic brakes, I could have compensated by squeezing harder.

 

[fooferdoggie]

get some alcohol and clean the rotor and caliper with it. I like to use a spray bottle. see if that helps.

 

[spokewrench]

get some alcohol and clean the rotor and caliper with it. I like to use a spray bottle. see if that helps.

Is that isopropyl? What strength? 70% used to be the usual, but I bought some 50%, and they sell 91% and 99%. I have used contact cleaner on a paper towel when I suspected grease contamination was causing an uneven response around the disk, and it worked. This is both disks, and the braking wasn't uneven.

I think it a lot of near-stops from 20 mph to fully bed a disk (smear it with melted pad material).

 

[fooferdoggie]

Is that isopropyl? What strength? 70% used to be the usual, but I bought some 50%, and they sell 91% and 99%. I have used contact cleaner on a paper towel when I suspected grease contamination was causing an uneven response around the disk, and it worked. This is both disks, and the braking wasn't uneven.

I think it a lot of near-stops from 20 mph to fully bed a disk (smear it with melted pad material).

I use 70% or above either one works whatever you have. see if it works. if it is grease in the pads then you would have to change the pads. I have a bike that was parked for about a year the brakes were worthless till cleaned.

 

[sc00ter]

I use Brakleen from Wally World, the red can, to clean rotors and related parts. Spray it on a paper towel as its very hard to spray slow and not have it splash all over. Oh, and the red can is NON-flammable, the green can IS flammable. That makes no sense to me but I'm pointing it out because the green can will beat-up paint if it gets on a painted surface. The red can is much more forgiving on painted surfaces.

 

[fooferdoggie]

I use Brakleen from Wally World, the red can, to clean rotors and related parts. Spray it on a paper towel as its very hard to spray slow and not have it splash all over. Oh, and the red can is NON-flammable, the green can IS flammable. That makes no sense to me but I'm pointing it out because the green can will beat-up paint if it gets on a painted surface. The red can is much more forgiving on painted surfaces.

the problem with those is they strip everything off the rotors and you have to re bed them. Plus they can strip the oil from the rubber boots around the pistons and cause issues.

 

[sc00ter]

If I spray Brakleen directly onto a caliper I follow it with a hot water rinse.

 

[fooferdoggie]

If I spray Brakleen directly onto a caliper I follow it with a hot water rinse.

its best no too its not needed and it can mess up the seals

 

[spokewrench]

I use 70% or above either one works whatever you have. see if it works. if it is grease in the pads then you would have to change the pads. I have a bike that was parked for about a year the brakes were worthless till cleaned.

I did a little more bedding and tested: 20 mph in 21 feet. I tried it again, and it took 26 feet from 19 mph. Huh??? I rode home to try your recommendation. In the process, I noticed that both levers would go to the bars. They weren't like that yesterday. If they wore that much from slowing down from 20 a dozen times, the pads must have been decrepit.

In the hot weather, I've kept the battery indoors. I've kept the garage open so it wouldn't be an oven in the day and it would cool at night. In the morning the relative humidity in the garage would be nearly 100%. I wonder if the pads can absorb moisture from humid air. If they can, they would stay damp because I haven't been riding it, which would dry the pads. I wonder if humidity caused deterioration.

I cleaned with alcohol and adjusted, and they work like new. I ordered new pads.

 

[spokewrench]

Here it is!

Suitable storage temperature and humidity for disc brake pads.- Zhejiang Changda Automobile Part Making Co.,Ltd.

Disc brake pads are an important part of the automobile braking system, and their performance is directly related to driving safety and driving experience. Prop...

www.zjcdbrakelining.com

I guess I need a heat pump and dehumidifier for my garage to maintain 10 to 25C and 40 to 60% humidity. They get soft stored over 60% humidity. If I'd taken it for a spin every few days, maybe they would have stayed drier.