Bad Brake rotors?

[swimmer7946]

So I replace my stock rotors after getting some pulsing and shaking coming down from speed...bike had 20k on it when this happend..I went with some new discs and everything was great except now when I come down from 80-90mph...i get a quick shake between 50-60mph...I cants believe i warped the rotors.....on a side note i didn't replace the pads...I changed them at 15k with new stock ones so I'm at a loss.....how do I check the trueness of the rotors?????

 

[GoldenChild]

replace pads and bed them in if not warped already should solve issue...what rotors did you replace them with?

 

[swimmer7946]

stock rotors..and i ran the pads across some 100 grit before i put them on...

 

[BA BUSA]

So I replace my stock rotors after getting some pulsing and shaking coming down from speed...bike had 20k on it when this happend..I went with some new discs and everything was great except now when I come down from 80-90mph...i get a quick shake between 50-60mph...I cants believe i warped the rotors.....on a side note i didn't replace the pads...I changed them at 15k with new stock ones so I'm at a loss.....how do I check the trueness of the rotors?????

You should always use new pads with new rotors...change the pads, scuff up the rotors and clean them with some Brakleen...then 'bed' them in properly

 

[dadofthree]

Hope it works out for ya, cause those rotors ain't cheap

 

[TruWrecks]

If you still get the vibes with the new pads it could be the rotors or the head bearings. Check both to be sure.

If the rotor is warped enough to matter you will notice it as you spin the wheel on the bike. It will catch in specific spots as it slips through the brake pads.

 

[HRJR]

Check the rotor with a dial indicator. The service limit on the front disc runout is 0.012"

Good luck.