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Discussion Starter #1
HI all,

Have Juicy 5s and I replaced discs as old ones were bent, but now it doesn't break as before. Brakes are lot weaker, brake force is about 40-50% less then before.

Do you have any suggestions?

Thanx heaps in advance
 

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igz said:
Have Juicy 5s and I replaced discs as old ones were bent, but now it doesn't break as before. Brakes are lot weaker, brake force is about 40-50% less then before.
Did you clean the rotors? Have you given them a few hard stops?

Any time you install new rotors or new pads, it takes a few stops to get everything working.
 

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Discussion Starter #3
I haven't cleaned them because they were new and looked very clean. Was I supposed to clean them with alcohol or something?
BTW, brakes are only few mnths old. So would few hard stops do the job? And also, is it normal for discs to bend caused by overheating them?

Cheers
 

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i had some hayes 9 breaks i did the same changed the rotors to 203 an had to bled them. like speedud said you do have to break them in to get them seated right.
 

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There's a difference between bent and warped. It's not unheard of for rotors to come out of true (warping) due to overheating or rapid heating/cooling cycles, or poor quality, or mishandling. Then there's bent, as when you step on it or bang it down on a boulder or tree stump. Warped rotors you can usually true up using rotor truing sticks or something as simple as an adjustable wrench.

Sometimes, during the manufacturing or packaging process, the rotor will get in contact with impurities that act to reduce friction. On new brakes you'll often smell "burning oil" (Mmmmm... ) as the rotor heats up on longer descents. After a few miles or a handful of hard stops, this will burn off and the brake system will come up to full power.

You can jump ahead by washing your new rotors with dish soap or alcohol. I never do -- just a ride 'er two'll do!
 

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Sanding the pads may help too- after a while, grooves form on both the pads and the rotor which help increase brake strength. Since you don't have any on the rotors, you're losing this part of the equation, and that's what's killing your strength.
 

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As a last resort, heat up the disks.
When my disks get slippy and I can't work out why, bake them at gas mark 3 for 20mins.

This always brings them back to better than new.
 
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