evilwerkz
2013-02-15 03:07:00 UTC
2008 with 7000 mi. Front brakes started to pulse a while back, pulled calipers and sprayed with brake cleaner pads and all, look really clean. No rain rides on bike. Rotors are clean and look new. Any ideas?
KTM666
2013-02-15 03:37:00 UTC
warped disks ?
weeksy
2013-02-15 07:36:00 UTC
Post missing.
No. 47
2013-02-15 07:44:00 UTC
bit of crap on one of the disks is also possible... but warped rotors most likley.
TLS_Russ
2013-02-15 09:47:00 UTC
Warped discs are the usual culprit for me but I've also had what felt like pulsing front brakes from worn out Michelin Pilot Road 2 front tyres which develop a curious serrated profile.
TLS_Russ
2013-02-15 11:30:00 UTC
Try new pads and deglaze the discs, some brake pads deposit material on the disc surface that can cause pulsing......
Also give the disc buttons a good spray with brake cleaner, these can get full of brake dust which stops the disc floating as they should,
Might save you a lot of money
Also give the disc buttons a good spray with brake cleaner, these can get full of brake dust which stops the disc floating as they should,
Might save you a lot of money
TLS_Russ
2013-02-15 19:05:00 UTC
novice rider, i doubt i have ever got the disks very hot. Will try to check for true. And then try new pads if so. $160 for pads, ouch! hope it aint rotors. Will check rotor buttons as well Thanks
TLS_Russ
2013-02-15 21:45:00 UTC
Try re-bedding in your brakes, it's the first thing I do when I feel a brake shimmy/pulse and has worked many times... and it's FREE!
Hotbrakes
2013-02-15 22:26:00 UTC
Post missing.
TLS_Russ
2013-02-16 01:27:00 UTC
Well checked rotors by putting zip Ty on fork and putting tag end up to rotor and spun them, they seem perfect. Spun all buttons and sanded rotors 80 grit wet/dry paper tryed to get cross grain scratches to maybe true the pads. Whent out for 50 mi blast all around Mt Tam in Marin CA unreal twisties!! 70 degreas and sunny. The new S20's are the best tyres I've had yet. no chicken strips super grip. Any way no change in brakes getting worse at slow speeds like pulling up to a red light.Thanks
PBRnr
2017-12-12 09:12:00 UTC
Searched quite a bit and followed various past suggestions to resolve pulsing front brakes, but still with the issue. Took the rotors off, inspected the wheel for casting defects (none apparent), lightly sanded both sides of the rotors, re-torqued rotors back to wheel w star technique, even spun each of the floater 'buttons'
I don't have an accurate way to measure run-out but visually cannot see any obvious warp to the rotors when I spin the front wheel up on the stands...considering the bike has <6k miles on it, i find it hard to believe the rotors could be warped, but is there any other cause for the pulsing outside of what I've already looked into?
I'm reluctant to buy new rotors unless i've gone over every potential cause w these oem ones first
I don't have an accurate way to measure run-out but visually cannot see any obvious warp to the rotors when I spin the front wheel up on the stands...considering the bike has <6k miles on it, i find it hard to believe the rotors could be warped, but is there any other cause for the pulsing outside of what I've already looked into?
I'm reluctant to buy new rotors unless i've gone over every potential cause w these oem ones first
No. 47
2017-12-12 10:02:00 UTC
Are all the caliper pistons freely moving back and forth?
The Gin Reaper
2017-12-12 11:53:00 UTC
PBRnr - you can crudely measure if there is any run out using a sharp pencil. Place tip against the disc and shaft of the pencil braced against suitable surface that wont move like the fork leg or brake calliper. Then rotate the disc slowly and see if the tip moves off the disc or breaks off depending on if the disc moves away or toward the pencil......
its crude but it works - may take a couple of attempts to brace the pencil properly.
its crude but it works - may take a couple of attempts to brace the pencil properly.
PBRnr
2017-12-12 15:08:00 UTC
Good ideas, will check pistons and pencil runout method. Cheers!
Aphex
2017-12-12 15:38:00 UTC
Post missing.
The Gin Reaper
2017-12-12 18:49:00 UTC
Also - have you changed the front wheel recently?
Ignore this - i've just reread your post
Ignore this - i've just reread your post
PBRnr
2017-12-13 06:42:00 UTC
I had the issue and nothing showed any signs of warping or Ill fitting rotors.
I went ahead and filed the castings and refitted the rotors, no more issues.
I think sanding is not going to help, you need to use a file.
I used a small hand smooth file and that did the trick for me.
Sent from my SM-G950F using Tapatalk
I went ahead and filed the castings and refitted the rotors, no more issues.
I think sanding is not going to help, you need to use a file.
I used a small hand smooth file and that did the trick for me.
Sent from my SM-G950F using Tapatalk
Aphex
2017-12-14 07:52:00 UTC
Post missing.
PBRnr
2017-12-14 08:19:00 UTC
A build up of pad material on the high spots of your disc can cause pulsing, also if your worried with the alignment of the callipers to the disc, loosen the calliper bolts, hold your brake (brake lever) hard in, so pistons lock to disc, then tighten the calliper bolts while the brake is locked on, you could put a zip tie on the brake, or get someone to hold it on.
battleshaft
2017-12-14 15:32:00 UTC
Post missing.
PBRnr
2017-12-15 08:15:00 UTC
thx. I forgot to say I lightly sanded the rotors when they were both off the rim. Just today cleaned off the pistons. maybe 1 of 4 were slow but all were mobile initially. Didn't have time to take a test ride after bolting things back together today
Fingers crossed.
Maybe the next step would be to swap out the brake pads tho the oem brembos on there right now have lots of meat left...
Fingers crossed.
Maybe the next step would be to swap out the brake pads tho the oem brembos on there right now have lots of meat left...
PBRnr
2017-12-15 09:08:00 UTC
Post missing.
PBRnr
2017-12-15 17:52:00 UTC
Good to know. I don’t understand why brembo pads seem to be so harsh on rotors...on my ‘83 bmw, they eventually wore grooves into the rotors around the cross drilled holes. Maybe they’d do better on higher grades of steel? At that rate probably higher performing pads out there as well...
Willh
2017-12-15 23:04:00 UTC
Tried to start bike, dead battery. Wanted to swap the lead acid for my shorai from the previous bike anyway, so did that. Took the bike to the shop to get a toolkit as the bike was missing it when I bought it.
Good news, no pulsing brakes! I think the cleaning of the rotors and pistons seems to have worked.
Bad news, bike died about 2 miles from home
Doesn’t appear to be charging the battery as it ran flat and now has not enough juice to run over.
Sigh
Good news, no pulsing brakes! I think the cleaning of the rotors and pistons seems to have worked.
Bad news, bike died about 2 miles from home
Doesn’t appear to be charging the battery as it ran flat and now has not enough juice to run over.
Sigh
PBRnr
2017-12-15 23:06:00 UTC
One kicker is that the oem toolkit doesn’t include a 5mm Allen key to even take off the battery fairing! KTM saw fit to include a bottle opener though as a final F U it seems as I sit here without power and without beverage
DribbleDuke
2017-12-16 01:06:00 UTC
Post missing.
PBRnr
2017-12-16 03:08:00 UTC
I tried but didn’t want to chew up the bolts so decided not to...
No. 47
2017-12-17 15:20:00 UTC
Post missing.
PBRnr
2017-12-17 18:46:00 UTC
No wonder there’s more black and orange around my home than green