Spongy Brakes

SSGT_B said:
Well, this was a bust. The lever is slightly better but a panic brake would leave me crashed if not for rear brakes. Still has some sponge to it. Going to try bleeding them once more before I say screw it and invest in a proper mc. I’m most likely not doing something right. Took a 40 mile ride and went to cyclegear and got me a new jacket and gloves though. That’s a positive.

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love that jacket, bike is looking good! I hate the rebuild didn't solve your issue
 
SSGT_B said:
Well, this was a bust. The lever is slightly better but a panic brake would leave me crashed if not for rear brakes. Still has some sponge to it. Going to try bleeding them once more before I say screw it and invest in a proper mc. I’m most likely not doing something right. Took a 40 mile ride and went to cyclegear and got me a new jacket and gloves though. That’s a positive.

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That has me stumped for sure...my gut says it's the MC......can't be glazed pads or rotors...? New lines, bled system....calipers are ok...what else can it be?????
 
SSGT_B said:
Cant see the pads being glazed, but heck, I can pull them out and knock the surface off. I must be doing something wrong is my guess but dunno what.
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Other than changing out the MC, I honestly can't see what would be giving you a spongy lever.

You've done almost everything possible...
 
Im thinking y'all are right. Ill back bleed the brakes for giggles and shirts. all the fluid is fresh so no worries about contamination. Then maybe find a sale or great coupon on a RCS unit
 
Yellow09 said:
...it's got to be that MC....
Click to expand...
Ok, I'll tell ya something about my Gen 1 M/C . . .
I have braided hoses . . that got rid of 90% of the spongy feel, the lever comes half way into the bar, then goes firm, and I mean firm, not rock solid but a good firm feel with no need to pull hard on it under braking at speed . . . I hate that the lever travel is so much before it goes firm but that is the nature of the design of these old M/C's, the piston travel is further due to the port diameter size that the piston has to travel across to block off then compress the fluid to transfer the pressure to the caliper pistons. also, there is twelve pistons to move as well, so that increases the travel as well. That is a lot of area in the caliper.
 
Kiwi Rider said:
Ok, I'll tell ya something about my Gen 1 M/C . . .
I have braided hoses . . that got rid of 90% of the spongy feel, the lever comes half way into the bar, then goes firm, and I mean firm, not rock solid but a good firm feel with no need to pull hard on it under braking at speed . . . I hate that the lever travel is so much before it goes firm but that is the nature of the design of these old M/C's, the piston travel is further due to the port diameter size that the piston has to travel across to block off then compress the fluid to transfer the pressure to the caliper pistons. also, there is twelve pistons to move as well, so that increases the travel as well. That is a lot of area in the caliper.
Click to expand...

My bike with the R1 Brembo has excellent lever feel and zero brake fade.

My Bandit had stock MC, braided lines and sintered pads it had brake fade after a bit of fast riding and heavy braking. I considered it to have really good brakes but they aren't even in the same category as the brakes on this Hayabusa of mine.

The MC sure makes a big difference, more than I thought.
 
Yellow09 said:
My bike with the R1 Brembo has excellent lever feel and zero brake fade.
The MC sure makes a big difference, more than I thought.
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The M/C is crucial to braking power and brake feel.
Think of the M/C like the front sprocket and the caliper like the rear sprocket, in a ratio application.
The ratio on the final drive is crucial to being in proportion to the amount of torque the engine is delivering, and in turn your hand pressure on the lever is like the torque applied, and the ratio between the M/C piston diameter and the caliper piston area is what makes the braking force powerful or weak . . . in short it's 'the leverage principle'.

Master Cylinder Math - JOES Racing Products

www.joesracing.com www.joesracing.com
 
Pity I'm not state side.. I have the 2014 oem m/c from where I replaced mine, it was in great cond.
You're more than welcome to it, but it would take a couple weeks to get to you at this time of year.
If you still want it, pm me and address and I can get it out maybe tomorrow - 24th.
But not sure when you would get it
 
Kiwi Rider said:
Ok, I'll tell ya something about my Gen 1 M/C . . .
I have braided hoses . . that got rid of 90% of the spongy feel, the lever comes half way into the bar, then goes firm, and I mean firm, not rock solid but a good firm feel with no need to pull hard on it under braking at speed . . . I hate that the lever travel is so much before it goes firm but that is the nature of the design of these old M/C's, the piston travel is further due to the port diameter size that the piston has to travel across to block off then compress the fluid to transfer the pressure to the caliper pistons. also, there is twelve pistons to move as well, so that increases the travel as well. That is a lot of area in the caliper.
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I have always disliked the braking on this bike from when I got it. I only recently started noticing the lever which started this off


Yellow09 said:
My bike with the R1 Brembo has excellent lever feel and zero brake fade.
Click to expand...

Did you have to get extended brake lines to set that up or is the stock length ok?

ottafish said:
Pity I'm not state side.. I have the 2014 oem m/c from where I replaced mine, it was in great cond.
You're more than welcome to it, but it would take a couple weeks to get to you at this time of year.
If you still want it, pm me and address and I can get it out maybe tomorrow - 24th.
But not sure when you would get it
Click to expand...

Thanks bud, no need to go through all that but I do appreciate the gesture. Ill give a few more things a try before I kick this mc out the door for another option. My concern ATM is if I go R1 or RCS19 will I need different brake lines? Might sound like a small item but I just bought these....LOL
 
If you keep the same lines, you may need one of these to make them fit without twisting the line too much..

superbikesupply.com.au

HEL Radial Master Cylinder Adapter Kit (CFA-01)

Stainless steel adapter which allows any brake line kit to fit to a radial master cylinder that has been fitted to the motorcycle as an upgrade. The adapter comes complete with M10 x 1.00mm bolts and washers (1x Single / 1x Double)
superbikesupply.com.au superbikesupply.com.au

1610091
 
SSGT_B said:
I have always disliked the braking on this bike from when I got it. I only recently started noticing the lever which started this off




Did you have to get extended brake lines to set that up or is the stock length ok?



Thanks bud, no need to go through all that but I do appreciate the gesture. Ill give a few more things a try before I kick this mc out the door for another option. My concern ATM is if I go R1 or RCS19 will I need different brake lines? Might sound like a small item but I just bought these....LOL
Click to expand...
Stock length worked on mine with Helibars
 
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