Brake help?

cornerslider

New Member
I've never owned a bike with ABS before this one. I figured I would just disable it when doing track days? Honestly, after riding it, I don't even notice the ABS (even on the track), so I don't disable it. I have a completely STOCK brake system. My last couple track days the front brake has been acting up. Sometimes the brake feels completely normal, other times it feels "soft" and the lever goes almost to the bars? I figured I got some air in the lines, so I bled the line- no air bubbles.... I rode it on the street for about 50 miles, all was normal. I went back to track yesterday, and it started all over again? I noticed when the lever felt "soft", that if I released the lever, and squeezed the lever again, it would feel "normal" again. This would USUALLY tell me that I have air in the line, and need to bled the brake (which I just did last week). I've heard the term "brake fade" before, but never experienced it. Does this sound like what I'm experiencing? It seems like it's random, except for the fact that it ONLY happens on the track. The only other variable is that I took the fuse for the headlight out (for the track). While I don't think that would effect the ABS system, I notice when I take the headlight fuse out, the speedo is WAY off, and random? My next step is to disable the ABS on the track to see if that is even a factor? I'm looking for any advise on this one. Does this sound like "brake fade", or something more? If it is "brake fade", what do I do about it? Is it just a pad thing, or more? Any help would be greatly appreciated-
 

D2M

Member
Country flag
Front rotor is getting hot. The OEM rotor is not floating so it may get a slight wobble in it when overheated ( you may not feel it on track at high speed ) and pushes the pads away from the rotor therefore more lever travel is needed to move the pads before they even contact the rotor. When you squeeze the lever a 2nd time the pads are already up against the rotor. This phenomenon is called " pad knockback " is very common in cars when driven on track. Buy a floating rotor all will be good.
 

cornerslider

New Member
Front rotor is getting hot. The OEM rotor is not floating so it may get a slight wobble in it when overheated ( you may not feel it on track at high speed ) and pushes the pads away from the rotor therefore more lever travel is needed to move the pads before they even contact the rotor. When you squeeze the lever a 2nd time the pads are already up against the rotor. This phenomenon is called " pad knockback " is very common in cars when driven on track. Buy a floating rotor all will be good.

That makes sense to me... I'll give that a try- thanks
 

cornerslider

New Member
I just ordered a 320mm floating rotor, and new pads from Hard Racing.... I will post my findings when they become available-
 

simpletty

Member
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I just ordered a 320mm floating rotor, and new pads from Hard Racing.... I will post my findings when they become available-


Best upgrade ever after suspension. That rotor and sauntered pads makes it stop like it has an anchor. I got rid of the abs as well and the brake feel is way better
 

D2M

Member
Country flag
I did a RC8 fork swap, this required a new rotor, brake lines ext. I am selling all the leftovers.
 

Ryanthegreat1

New Member
I am experiencing the exact same thing on the track with the stock rotor. Curious to see if the floating rotor resolves the issue. Kills your confidence when the brakes are not the same corner to corner.
 

cornerslider

New Member
Mine is supposed to be here on Thursday (as well as my upgraded pads). I'll be putting it on before my track day on Saturday. I'll post my findings to this thread by Monday at the latest-
 

Diploman

New Member
The 320 rotor along with sintered HH pads represents a major brake upgrade on the 390. Good move.

If you continue to have variable lever travel, this may come from two different sources:
1.--Air in the system. Sometimes there can be residual bubbles that are difficult to eliminate with conventional bleeding. One effective technique to deal with these is the "Overnite Squeeze". Simply tie the brake lever to the throttle under pressure overnite and let the sustained brake fluid pressure squeeze out tiny, hidden air bubbles. Surprisingly effective - I do this about once a month just as a prophylactic.
2.--Water in the brake fluid. Brake fluid is very hydrophylic - ie, it attracts water, which can enter the system from accidental leaks or humidity in warm air. Even a can of brake fluid left open for a couple of hours on a hot day can introduce water if subsequently used to fill a brake system. Under the intense heat of braking, a small drop of water in the system will produce steam - a compressible gas - and will result in brake fade/ longer lever travel. The remedy is simply to pump out old fluid by replacing it with fresh,new, just-opened fluid.
 
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cornerslider

New Member
The 320 rotor along with sintered HH pads represents a major brake upgrade on the 390. Good move.

If you continue to have variable lever travel, this may come from two different sources:
1.--Air in the system. Sometimes there can be residual bubbles that are difficult to eliminate with conventional bleeding. One effective technique to deal with these is the "Overnite Squeeze". Simply tie the brake lever to the throttle under pressure overnite and let the sustained brake fluid pressure squeeze out tiny, hidden air bubbles. Surprisingly effective - I do this about once a month just as a prophylactic.
2.--Water in the brake fluid. Brake fluid is very hydrophylic - ie, it attracts water, which can enter the system from accidental leaks or humidity in warm air. Even a can of brake fluid left open for a couple of hours on a hot day can introduce water if subsequently used to fill a brake system. Under the intense heat of braking, a small drop of water in the system will produce steam - a compressible gas - and will result in brake fade/ longer lever travel. The remedy is simply to pump out old fluid by replacing it with fresh,new, just-opened fluid.

Thanks for the help. I already tried the "squeeze-over-night" method... Got nothing from it. If the rotor/sintered pads don't fix the problem, I'm going to have the flush the whole system with new fluid (I hope not)-
 

=maz=

Member
Country flag
Thanks for the help. I already tried the "squeeze-over-night" method... Got nothing from it. If the rotor/sintered pads don't fix the problem, I'm going to have the flush the whole system with new fluid (I hope not)-

I'm not sure if you've tried a Vacuum Bleeder but that made the difference for me. My wife had been complaining about her brake-lever feel for ages and no matter how many times I tried bleeding it or leaving the lever pulled back it just made no difference...purchased a Vacuum Bleeder, spent a bit of time on the job, finished off with the usual bleeding technique and her brakes are now awesome. We are both still using the standard MC, disk, pads and lever, I have removed the ABS system from my bike but have not done so to hers yet and there is little difference between the two bikes braking feel.
I would like to go to the floating 300mm disk for next season(we are not allowed to use the 320mm disk in our production class.
 
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cornerslider

New Member
I'm at my local track right now, and pleased to announce my findings with the Galfer 320mm floating rotor & sintered pads..... I took a few sessions to get the pads to seat in, but now- IT ROCKS!!!!! I got the whole set-up from Hardracing. I highly recommend anyone experiencing what I experienced (I started this thread) give this a try. My brakes are awesome now [emoji41][emoji1360]


Sent from my iPad using Tapatalk
 

HardRacing

Supporting Vendor
Country flag
I'm at my local track right now, and pleased to announce my findings with the Galfer 320mm floating rotor & sintered pads..... I took a few sessions to get the pads to seat in, but now- IT ROCKS!!!!! I got the whole set-up from Hardracing. I highly recommend anyone experiencing what I experienced (I started this thread) give this a try. My brakes are awesome now [emoji41][emoji1360]


Sent from my iPad using Tapatalk
.

That's great to hear.

Thank you for posting the feedback. ;-)

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