Tracer 900GT Front Disc Bobbins

[Lone Wolf]

Bobbins - It's a floating rotor thing

Edited March 14, 2023 by Lone Wolf

[PhotoAl]

On 3/11/2023 at 10:27 PM, Lone Wolf said:

One of the potential causes is when someone brakes hard and comes to a complete stop, there can be a deposit of brake pad material at that point on the rotor (where someone stopped completely). That can cause a pulsating feel in the lever.

If someone really wanted to nail down the cause, they would do one thing at a time (for example leave the bobbins alone, and just see if doing the disc clean and new pads made the pulsing go away).

Guidance when bedding in new pads is to do several controlled braking cycles but DON'T come to a complete stop, for this reason. Especially important when transferring fresh pad material to a fresh rotor (or cleaned rotor).

Once bedded in, we should be able to come to a complete stop without putting a gob of pad material down, but if they are pulsing that is one of the remedies to consider to fix it.

Good information.  My Tracer surprised me to do this as it is the first bike I've had to do it and generally do not stop that hard with it, particularly stop hard from speed and come to a complete stop.  It was defiantly just one spot on the rotor(s) which "grabbed".  The OEM pads were not that great and replaced them with HH pads when I cleaned the rotors.  LOL yup the first ride on the new pads was interesting, riding a couple of blocks with stop signs before a place I could bed the brakes in.  Bike also gets ridden in all kinds of weather conditions.  Last trip rode thru road construction where they had wet down the gravel which made for a nasty dirty bike but brakes did fine.  Have to wonder i the cause may have been related to the OEM pads and a hot stop.

I've had a couple of super sports and a Yamaha FZ6s which were braked much harder.

Edited March 14, 2023 by PhotoAl

[Turd Ferguson]

Here is a demo how its done. My son's 790 Duke had the problem of "warped rotors" that is very common on those bikes. I spun cleaned the disk rivets like in this video and all is good. When you think you have warped or dragging rotors do this first!