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Rear break question


Keithaba

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Only had my 99 BB for a few days, but have ridden about 200 miles. I noticed that when engaging just the rear break, I swear I could pound the pedal, and the rear tire won't lock up.

It has new rear pads on it, so on my slab ride home, I gently breaked frequently at speed to get the pads to set a bit more.

Now 200 miles later, I think I could stand on the rear brake and it won't lock up the rear tire.

However, if I apply front and rear break at the same time, it seems spot on.

Is this just noraml due to the linked break system? Or is it possible there is some air in my rear break lines?

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Is this just noraml due to the linked break system? Or is it possible there is some air in my rear break lines?

I have over 60K on mine and have yet to lock up the rear try as i may, Yes I would say what you are experiencing is normal for the XX that is still linked, I could lock up the rear on my cbr1000f no problems then again it was not linked.

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I don't know if it is normal. I have locked the rear tire several times on my ST and it is linked also, but yet to do it on the XX.

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You're probably fine, but no one can tell from a distance if you have or don't have air in the system.

The back brake exerts force on only the center piston of the rear caliper. The front brakes exert force on the outer two pistons of the rear caliper. If you have applied the front brakes, and apply the rear brake as well, the back should lock up.

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You're probably fine, but no one can tell from a distance if you have or don't have air in the system.

The back brake exerts force on only the center piston of the rear caliper. The front brakes exert force on the outer two pistons of the rear caliper. If you have applied the front brakes, and apply the rear brake as well, the back should lock up.

That makes sense. When I apply front and rear break, there is less play, and it feels fine. Didn't think there was air in there, but it's just different.

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Rock Me Up....

Slight correction !!

"its the device used to balance with the throttle to keep the front end up at the right angle."

Should read "correct angle."

Somebody might try to turn right..

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Sorry, I never use the thing.......with one exception. When I'm stopped on a slope and want to take my hand off of the front brake lever while sitting still.

Edited to add............I think I might be an official member of the Geritol set :icon_surprised:

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You're probably fine, but no one can tell from a distance if you have or don't have air in the system.

The back brake exerts force on only the center piston of the rear caliper. The front brakes exert force on the outer two pistons of the rear caliper. If you have applied the front brakes, and apply the rear brake as well, the back should lock up.

I was told or read(can't remember what way) that, applying the rear brake, uses the centre pistons on each front brake and the two outer piston's on the rear brake. Applying the front brake, applies the two outside pistons of each front brake, and the centre piston on the rear.

Anyone know for sure what one is right?

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From the braking system diagram in the manual: The rear pedal activates the centre rear and front left pistons directly, and via a pressure "delay" valve, the front right centre piston. Once the front left is used (either by lever or pedal), it will rotate due to drag from the disc and actuate the outer rear pistons on the rear, via a proportional control valve using the secondary master on the left fork leg.

So effectively, when you brake hard with the pedal you use both front centre pistons and all 3 pistons on the rear. Brake gently, you only get the rear centre. In between, you get a mix of both.

Note: When bleeding the brakes, the front master only feed fluid to the front outer pistons. The front centre and all rear pistons are fed from the rear reservoir. This makes bleed order critical.

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From the braking system diagram in the manual: The rear pedal activates the centre rear and front left pistons directly, and via a pressure "delay" valve, the front right centre piston. Once the front left is used (either by lever or pedal), it will rotate due to drag from the disc and actuate the outer rear pistons on the rear, via a proportional control valve using the secondary master on the left fork leg.

So effectively, when you brake hard with the pedal you use both front centre pistons and all 3 pistons on the rear. Brake gently, you only get the rear centre. In between, you get a mix of both.

Note: When bleeding the brakes, the front master only feed fluid to the front outer pistons. The front centre and all rear pistons are fed from the rear reservoir. This makes bleed order critical.

You can get the rear to lock by just using the rear pedal but you "REALLY" need to stamp on it hard, I have only done it once last year when I was using the rear only 95% of the time due to Tendonitis in my right hand and went to haul myself up from ~120kmh for a corner :icon_surprised:

I also believe that is why some people find the rear pedal a bit "wooden" when using it lightly as only the one piston is operating but once you put more pressure on it she feels much better :icon_confused:

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if you really want the back tire to skid, just get her up to speed, clutch, shift to first and drop clutch....

screeeech!!!!!!!!!!!

(soooo much engine drag)

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It is different. Some folks don't like it. Most do. Takes a bit to get used to it. It works well....even the people who don't like it will admit to that much.

I don't mind it, just felt squishy at first. Particularly in comparison to most other bikes I've had (Fz1, 919, FJR...).

No complaints about overall braking power, just that I'm not on the track, so I do use the rear brake, and sometimes trail brake because I am a big fan of late apex or delayed apex on the street.

Did I mention, this bike is freeking fast! :icon_evilgrin:

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I have delinked my brakes as part of the RC51 front end swap I completed. I drilled the center caliper piston to the internal supply line feeding the outside pistons on the stock rear brake caliper. I used the stock rear mastercylinder with one brake line feeding the front piston on the rear brake. I plugged the center piston feed line (previously from the front brakes), and left the bleeder on the rear piston of the back caliper. I can definately lock up the rear brake now. I am using EBC HH pads on the OEM disk, no need for anything fancier than that.

On the front I am using ferrodo pads on full floating brake tech discs with stock RC51 calipers. After bedding them in I can attest to the fact that they stop faster than with the older OEM setup. Very happy with the RC51 front end swap and improvement in braking.

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