Originally Posted by TT750
hey was thinking about putting a brembo master on this winter. just was curious if i should go for a newer r1 master from a r1 with 6 pots or is it same the same as the old 4 potters from the early mid 2000 r1/r6. The r6 carries the same pn but the r1 pn changes some when they go to 6 pots
09 r1 14B-W2587-00-00
05 r1 5VY-W2587-10-00
05 on r6 5SL-W2587-00-00
anyone ever look into this?
Does that mean I've found anything? well...
First of all, let me apologize for bumping an old thread. I hate bumping old threads; actually I don't, I hate getting yelled at for it.
I asked this very same question on an R1 forum a while back. I got no reply.
I personally believe Yamaha changes part numbers on similar items just so they can charge different prices, but that is neither here nor there...
Anyway, when I asked before, I noticed the different part numbers, so I checked the part numbers for the pistons inside the masters. They were also different. I just now checked and all of the model numbers have been superseded by... the exact same part number (2S3-W0041-00-00).
This means that the 05+ R6, 05-08 R1, and 09+ R1 all have the same piston diameter (16mm I believe, but I could be wrong. I can check mine tonight if it is important to you).
So now I look to the brake levers. Well all three models use a different part number. That's annoying. I then went to CRG's and Pazzo's website and they both say that the 05+ R6 and 05-08 R1 take the same aftermarket lever (which makes sense) and that the 09+ R1 uses a different lever.
So what that means is that for the 4 piston calipers, Yamaha uses similar front master cylinders, and the newer R1, with the 6 piston calipers, gets something else. For example (I am making these numbers up) let's say that the 4 pot masters are 16x20 then the newer R1 master could be 16x24 or something like that. My assumption is that they changed the lever ratio to pump more fluid into the (assumed) bigger 6 piston calipers. (Note: I put assumed because it is POSSIBLE
to have 6 pistons with less area than 4)
Originally Posted by SPL170db
The R6 and older R1 calipers have relatively smaller pistons in them (30mm and 27mm pistons in each). Not sure what the piston sizes are in the new 6-pot R1's. But bear in mind that piston surface area when choosing what size master cylinder to go with.
That, to a great deal, will affect the power and feel you have at the lever.
This is exactly right. I don't know what the OP has, but the SRAD 600 calipers are 30mm and 27mm.
The SRAD 750's are 27mm 27mm and 24mm. I think that the slingshot 750's 6 pistons are all 27mm.
And not that it is related, but I think that all of the GSX-R Radial Tokico calipers are 34mm and 30mm, and I believe the new Brembo radials on the newer GSX-R's are all 32mm. Also, interestingly enough, both of these calipers have a greater surface area than the 6 piston SRAD calipers.