Please help, on my 2012 front brakes it seems fine on high speed but on lower speed I can feel the front brake lever pumping in my hand when coming to a stop.

I replaced the front brakes but still the same. Also checked for air and all seems fine. Bike has Carbon front wheel and aftermarket wafe disks.

Any suggestions. Much appreciated

Discs not seated true on the wheel
Mounting surface on the wheel not true to rotation
Disc not true or warped

At higher speeds you might not feel it as more than just a shudder. Its not until you slow down when you start to feel actual push back or pulsing of the brake lever.

If you push the bike forward or lift so you can spin front wheel an gradually apply front brake you might feel it drag a little but then roll free and then drag again indicating warped disc.

* Last updated by: david5525 on 4/7/2019 @ 11:13 AM *

I've used this place before. EXCELLENT !

https://truedisk.net/

Aftmkt disc is the problem. As Dave mentioned, take a coat hanger and make an L shape tool so the one length is duct-taped to the fork, the next length of the L reaches far enough to almost touch the outer diameter disc. Spin the front wheel and watch the gap increase or hit the L tool tip being dragged upon. That or take a long screwdriver shaft, hold it against the fork, then run a business card gap at the driver's tip to outer edge of the disc and note the in and out movement begin to get close to the tip and then move away from the tip when spun.

The danger/downside to the warp disc is the pads will be pushed back into the caliper and you'll have to pump the brake back up just to stop.