Pulsing brakes

[Trials]

I kind of feel like it probably is too but I’ll try the other things first. Cant get over the fact that two damn front rotors are going to set me back over $400 CDN.

Those brakes, in order to work, they have to pry against 40$ worth of deep grove roller bearings.

 

[TK4]

Galfer USA makes replacement rotors, likely EBC and other companies do too.

 

[Trials]

You can measure imperfections and damage to rotors if there is any. You check them for thickness and you check them for flatness
and if they are flat and the same thickness throughout, then a damaged rotor ain't the source of your inconsistent braking problem.

... and it's a hydraulic brake piston, hydraulic pistons and cylinders need to be clean, not lubricated.

 

[ReSTored]

I do but not near the bearings.

I've used a pressure washer once to do a general clean up of the bike the day before I planned to pull the wheels and clean the pads, calipers etc.... I was very careful to keep the spray away from the axle area and the shaft drive. Nonetheless, next day on tear down there was evidence of water intrusion that I was able to deal with before I had issues. I assuming what happened is that the high pressure stream of water was deflected somehow and still had enough force to push past the seals. So before buying new rotors you may want to pull the wheels and check those bearings again.

 

[VFR.CBR]

Pulsing brakes had been common problem for me on my track bike, not so much on my street bike. I was using EBC HH pads on both bikes, still have them on the street bike and they work great. The problem at the track turned out to be pad transfer. The interface between the rotor and pad gets hot enough to transfer minute amounts of melted pad to the rotor. This would develop into a slip-stick pulsing under braking. There was no real pulsing at the lever.

Now at the beginning of each season I hone the rotors with a Brush Flex-Hone mounted in a drill press and use full on race pads (DP) on the track.

My street bike is heavier but never sees the high speed high load braking the track bike does and I think I've only done those rotors once.

 

[Wingboy]

Pulsing brakes had been common problem for me on my track bike, not so much on my street bike. I was using EBC HH pads on both bikes, still have them on the street bike and they work great. The problem at the track turned out to be pad transfer. The interface between the rotor and pad gets hot enough to transfer minute amounts of melted pad to the rotor. This would develop into a slip-stick pulsing under braking. There was no real pulsing at the lever.

Now at the beginning of each season I hone the rotors with a Brush Flex-Hone mounted in a drill press and use full on race pads (DP) on the track.

My street bike is heavier but never sees the high speed high load braking the track bike does and I think I've only done those rotors once.

Flex hone is money very well spent. I need to get a new one.

 

[slowbird]

On my current VFR I changed the pads from whatever pads the previous owner had installed on them to EBC HH pads, which I have used on all my bikes. When I took them for a test ride I immediately noticed an unevenness in the brake feel. But only at low speeds and when coming to a stop. I was confused because the brakes seemed fine before and I didn't touch the rotors so I couldn't possibly have bent them. I took the pads out again and double checked everything but it all looked good. I eventually caved and took it to Donald at Platinum because I had a big bike trip coming up. He checked it out and said the rotors were bent but not by a lot. Most likely like that when I bought them but it only became noticeable when I added the grip-ier pads.

The VFR800 I had before was sold to me certified with an incredibly insane amount of brake pulsating at any speeds. Rotors were warped to **** and the bike didn't even have 20k on it. The only solution was dishing out an arm and a leg for new rotors. Seems these rotors are prone to getting damaged/warped. No amount of cleaning the bobbins helped.

I ended up buying a set of EBC rotors and installed them last year. Smooth braking has returned.

 

[shanekingsley]

On one of my previous bikes, I lived in a sketchy part of town and developed a bad habit of riding off without taking my disc lock off first. Usually I would get about 12” or so and then the bike would stop and drop. Warped the rotors quite nicely among other things. I was pretty broke back then and rode a whole season using only my back brake, because the fronts pulsed so badly.

I never used the disc lock again.