Brembo clutch master cylinder on Gen 3
- Thread starter Flows
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dcnblues
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The stupidest the bike has made me feel was working on problems with first gear. Doing all kinds of research into the quick shifter and updates and pushrods and bleeding the clutch system etc etc. FINALLY realized the foot lever needs a huge amount of travel down from neutral to first as opposed to regular down shifts. And as I had adjusted the lever down for comfort as I am tall, it was hitting the stock kickstand which caused resistance and created issues getting into first. And there isn't a quick or easy fix. I got a TRX aftermarket lightweight kickstand, I think I put a spacer on the lever Bpivot bolt, and I bent the toe lever outwards to help. And I put a spacer between the kickstand pivot notch and the frame to hold the kickstand a little lower when up. It's manageable now but the two still fight for space. I get that the mounting points for the kickstand are really hard to change on the aluminum frame, but I wish Suzuki made it easier on us tall guys. We don't fit on liter bikes, so I would guess Busa owners tend towards tall. Do make sure that's not your issue...
I just rotated the kick stand mounting plate forward in it's hole slack and re-tightened for that one.
This is a hydraulic leverage issue. I have the RCS CC set to 18 on the leverage and it is still not enough throw to fully dis-engage.
Are there any clutch slave cylinders for Suzuki that have piston size options or potentially a sleeving kit available?
K-factory make a bigger one https://japan.webike.net/products/24760519.html 36mm rather than 33.5mm but I need to go smaller.
When I have the OEM master cylinder installed the issue goes away.
This is a hydraulic leverage issue. I have the RCS CC set to 18 on the leverage and it is still not enough throw to fully dis-engage.
Are there any clutch slave cylinders for Suzuki that have piston size options or potentially a sleeving kit available?
K-factory make a bigger one https://japan.webike.net/products/24760519.html 36mm rather than 33.5mm but I need to go smaller.
When I have the OEM master cylinder installed the issue goes away.
Copy, I know people that are using 16mm masters without issue. I think these new CC RRs may have a shorter throw.
Mine is 55mm at 130mm from the pin.
I would like to try and make the RCS16 CC RRs work either by a mod to increase the throw or a smaller / sleeved slave cylinder.
Any clever ideas?
Mine is 55mm at 130mm from the pin.
I would like to try and make the RCS16 CC RRs work either by a mod to increase the throw or a smaller / sleeved slave cylinder.
Any clever ideas?
Ok I get it. The OEM is a traditional bell crank (27.5mm from pivot to bell end) with much lower mechanical leverage but a 12.mm piston. Also OEM travels 80mm at 130mm from the pin rather than only 55mm for the RCS, one of the limitations of a radial arrangement. Essentially the RCS16 has 4.3% less leverage but ultimately pumps 28.5% less fluid due to the short throw. Maybe radials are a dumb idea for clutches especially as the fluid displacement increases as the leverage decreases on clutch pull. Kind of makes the OEM ideal for fine clutch control as the leverage increases toward the end of the release..
OEM:
OEM:
| Master cylinder bore / piston diameter | Approx. 12.7 mm (0.500 in) | — |
| Release cylinder bore / piston diameter | Approx. 33.6 mm (1.32 in) | — |
Looks like this might work, checking on the base dimensions. Anyone know if a Gen 2 slave fits on the Gen 3 when rotated 90 degrees?
30mm Clutch slave cylinder
For GSXR1100 & GSX1400, to be used with Brembo 12mm Master cylinders
www.extremecreations.com.au
While the combined mechanical and hydraulic leverage for the RCS16 CC RR (31.65:1) is about the same as the Gen3 OEM (32.81:1) the Fluid Displacement for the RCS16 CC RR is 36.7% less than the Gen3 OEM.
The Gen 1 and 2 slave cylinders are interchangeable but the Gen 3 has a different footprint.
Does anyone have the master cylinder bore diameter, stroke and lever bell crank lengths for the OEM Gen 1 and Gen 2?
The Gen 1 and 2 slave cylinders are interchangeable but the Gen 3 has a different footprint.
Does anyone have the master cylinder bore diameter, stroke and lever bell crank lengths for the OEM Gen 1 and Gen 2?
| RCS16 Corsa Corta RR | |
| Bore Diameter / Piston Area | 16mm / 201mm2 |
| Piston Stroke / Fluid Displacement | 8mm / 1608mm3 |
| Mechanical Leverage at 130mm | 16mm pivot to piston setting = 8.125:1 18mm pivot to piston = 7.22:1 |
| Axial OEM | |
| Bore Diameter / Piston Area | Gen1 = ??? / ?, Gen2 = ??? / ?, Gen3 = 12.7mm / 127mm2 |
| Piston Stroke / Fluid Displacement | 20mm / 2540mm3 |
| Bell Crank / Mechanical Leverage at 130mm | Gen1??? = ?, Gen2??? = ?, Gen3 27.5mm bell crank = 4.73:1 |
| Slave Bore Diameter / Piston Area | Gen1=38/1134, Gen2=36/1017, Gen3=33.5/881, K-Factory for Gen3=36/1017, Oberon for Gen2=38/1134, ExtremeCreations for Gen2=30/707 |
| Hydraulic / Combined Leverage | RCS16 CC RR: 38mm slave = 5.64/40.72:1, 36mm slave = 5.06/36.53:1, 33.5mm slave 4.38/31.65:1, 30mm slave = 3.51/25.4:1 OEM Gen3: 38mm slave = 8.93/42.23:1, 36mm slave = 8.01/37.88:1, 33.5mm slave 6.94/32.81:1, 30mm slave = 5.57/26.33:1 OEM Gen2: 38mm slave = ?/?, 36mm slave = ?/?, 33.5mm slave ?/?, 30mm slave = ?/? OEM Gen1: 38mm slave = ?/?, 36mm slave = ?/?, 33.5mm slave ?/?, 30mm slave = ?/? |
Thankyou...now my brain hurts...
OK, OEM Bore Diameter / Piston Area for Gen 1 = 15.85mm / 197.21mm2 Gen 2 = 13.98mm / 154.42mm2
Now we just need:
Now we just need:
- OEM Piston Stroke for Gen1 and Gen 2
- OEM Bell Crank length from pivot to push point for Gen 1 and Gen 2 clutch levers
- A bike with a 30mm slave piston or an aftermarket Ti or Alloy option
- Someone to pull apart a Brembo RCS16 CC RR to see if you can machine the spring holder down and get some more fluid displacement without causing a leak or hydraulic lock. Yes, yes, that may well end up being me...
Riiight.. So the Brembo RCS16 actually has a 15mm piston and the RSC17 has a 16mm. Such a d!ck move from Brembo Marketing.. That explains (just about) everything.
@Dai. 18 is the pivot to push point measurement, you will have to measure piston stroke with some Vernier calipers or measure it at 130mm on the lever from the pivot and we can calculate it from there. Brembo don't publish anything useful on their gear nor respond to requests about it when asked. Up to us to actually measure things. My bet is that the Billet 16 actually has a real 16mm piston..
@Dai. 18 is the pivot to push point measurement, you will have to measure piston stroke with some Vernier calipers or measure it at 130mm on the lever from the pivot and we can calculate it from there. Brembo don't publish anything useful on their gear nor respond to requests about it when asked. Up to us to actually measure things. My bet is that the Billet 16 actually has a real 16mm piston..
My eyes glazed over about 3 lines into that chart . . . I gotta go take a nap.
Sheesh, I just pull my OEM Gen 1 clutch lever and it works.
Brembo replacement appears to be a whole lotta hassle for very little if any gain ar all.
Switches on clutch m/cyls (brembo clutch and brake) are a pain to sort as well.
I'll stick with stock, cause I'm cheap and lazy lmao.
Brembo replacement appears to be a whole lotta hassle for very little if any gain ar all.
Switches on clutch m/cyls (brembo clutch and brake) are a pain to sort as well.
I'll stick with stock, cause I'm cheap and lazy lmao.
Kids these days..
Yeah nightmare so far. Will get to the bottom of it one way or another.
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