OK, so I've had this bike a few months now. I thought I'd get used to the front brake, but something's up with this thing.

Sometimes it's super grippy, sometimes it feels like I really need to pull hard to get the bike to slow down. Not really predictable, and I can't figure out what's changing. I notice this at slow speeds coming to a stop, where sometimes the bike rolls farther than I expected, and sometimes snaps to a stop, which is disconcerting.

It may be doing it at higher speeds too but I haven't noticed.

It's not spongy and weak (rules out weak lines or air), and it's got a solid feel (rules out leaking.) It's just not consistant.

I haven't ruled out rider error but I can't figure out what I could be doing to cause this. My old bike, a twin disk CB900F, had spongy brakes which I fixed with a set of teflon lines, but I never had this braking issue on it.

Any ideas?

Your giving throttle while trying to break. Thus your throttle is too far towards you and when your hand rolls forward on the throttle to grab the brake, it is still giving a little throttle.

Michael

i had the grabby/not grabby thing happin on my last track day with the GS.  It ended up being some corrosion between the brake lever and the master cylinder piston.  Sometimes it would just glide past and I'd have good brakes.  Other times it would hang up and I'd have crap brakes.  I ended up ruling out everything else before I found the problem.  It was an easy scotchbrite and lube fix.  Probably not your problem, but you never know.

Quote from: mister on November 12, 2009, 10:51:51 PM
Your giving throttle while trying to break. Thus your throttle is too far towards you and when your hand rolls forward on the throttle to grab the brake, it is still giving a little throttle.

I'm not doing that. While this is going on I've pulled the clutch so throttle position isn't in play anymore.

I'm actually replacing the lever next week; I'll check the pivot condition then. Hopefully it's that simple.

Quote from: ineedanap on November 12, 2009, 11:33:16 PM
i had the grabby/not grabby thing happin on my last track day with the GS.  It ended up being some corrosion between the brake lever and the master cylinder piston.  Sometimes it would just glide past and I'd have good brakes.  Other times it would hang up and I'd have crap brakes.  I ended up ruling out everything else before I found the problem.  It was an easy scotchbrite and lube fix.  Probably not your problem, but you never know.

Actually it was close to this. The pivot was corroded up. I'd sprayed it with a lube yesterday to see if this was the issue; this morning after reading this decided to take the time to pull the lever off and look inside.

While the pivot was working, it wasn't silky. I pulled the pivot bolt and found rusty bits inside. I think these were binding under braking pressure, while you didn't notice them with just a quick squeeze. Emory cloth, clean and grease and now it seems fixed.