I have read all 7 pages of this post and nowhere did I see if CBR900RR calipers and M/C work..can someone tell me.

 

92-97 CBR900RR uses the same calipers as the VTR. 98-99 uses the same calipers as the F4i... just a dufferent color AFAIK.

 

Thanks Daniel, they looked very similar but for color but the black makes the 900 calipers appear more stout. What about the M/C do you happen to know the bore?

 

no, sorry.

 

my expirience is
i got my VTR with GSXR750 USD front and 6 pots, but the VTR OEM MC
the bike was not stopping well and there was no feel at the lever at all
the MC was too small for these 6 pots
so i bought Nissin Radial MC, not sure what bike it was from, but i did a huge difference - more fill, more stopping power
so for my this combo is a great mod


and about the MC sizes i got some researches, because i needed MC for my Supermoto

radial and axial MC sizes are e bit diffrent
for 4 pot calipers use 14mm axial or 17-18mm radial MC
for 6 pot calipers - 16mm axial(the original gsxr is 16mm) and 18-19mm radial

i got a brambo axial MC that came with gsxr 6 pots, sold the 6 pots(the VTR already had ones) but still got the MC
if someone is interested send me a PM
i have advised it for 60BGN(about 40$) here in Bulgaria, however the shiping may be a bit expensive

 

Just sharing my f4i front brake conversion mod. After my f4i front end swap, i decided to swap over to f4 brake calipers and MC.

Initially i had f4i calps, OEM honda pads and the OEM Shawk MC (14mm). While the stopping power was amazing, it was way too touchy. It lacked feel, far too much of an initial bite, lever travel was too lengthy and overall, was not progressive enough for my taste and needs.

I eventually swapped over to the F4i MC (15.87mm). Dramatic difference. While the stopping power was there, it is a little bit deeper in the well. The slightly increased effort and shortened lever pull made braking a far more progressive task. It's as if I now have a much more responsive and direct finger-feel to caliper-pinch.

 

So I am thinking of swapping my stock front to a rc51 or 900rr but can't decide yet. From what I read, all the brakes listed should be interchangeable between the rc51,cbr600,900,929,954,f4i? That should mean I could put any of these calipers that are listed to fit, on any fork conversion that I choose? What about discs? Would they all fit the different calipers?

 

The discs have to match the forks, as that is determined by wheel width / fork - caliper mount spacing. (or if you use bigger discs then you need brackets that space the calipers further out)

As for the rest of it, 900rr is very different from RC51 or 929/954RR forks. 900rr are not USD forks.. so be careful there, and I don't know what brakes they use.

But RC51/929/954/f4i will all bolt to RC51/929/954/F4i forks.. They do have different performance qualities between them, but they will all work. (F4i/RC51 are "better" than 929/954)

 

Question, if I use a MC from a VFR750 (1/2 or 12.7mm bore) with my VTR calipers, I should better braking? Is my logic right, by using a smaller bore MC I'll get better leverage?

 

No, not better braking, more lever travel. You wont get an improvement that way.

 

I also have a Brembo 19mm MC, if I use that I would have less lever travel, and then more powerful (and sensitive) brakes?

 

You could try the brembo but diff combos reap strange results. The easiest way would be to get cbr600 calipers and master. Really cheap and huge upgrade.

The brembo will move more fluid but I have seen guys do that and get wooden brakes.

 

Yep. Lot of factors involved including mc design and pad compound, but it's also about leverage ratios. Straying too far from the oem ratios of mc bore to caliper piston sizes is a recipe for unsatisfactory braking performance.

 

Sticky!! Tons of useful info and after 17,8xx views this thread deserves it.

 

here is the table that was posted in the UK Forum I realised that it was never posted here and only a link to the thread.
also the text from a review carried out on brake mods in a UK bike magazine:

Intersting article in the Feb PB mag on caliper and MC upgrades on their project GSXR1000K1 which as standard is fitted with 6 piston calipers and 15.6mm MC.

They tried 4 set ups, stopping from 100mph, measured in metres.
a) stock with old stock pads - 104m to stop
b) stock with new EBC HH pads - 93.7m
c) 4 piston Tokico calipers off SV1000 [they say 10% less pad area but 6% more piston area than stock] with EBC HH pads and stock MC - 86.8m
d) as c) but with a big bore [18.75mm] MC of a GSXR 750 K4 - 97.5m

What the data logging shows is that the hydraulic leverage ratio in set up c) was most powerful, and the big bore MC made the leverage ratio worse so had reduced stopping power.

But the test rider feed back was the opposite:
with set up c) tester said "initially these felt like we had gone back to set up a) then I realised I had much better feel; they seemed smoother and more controlled. There was more lever travel but the brakes felt more progressive after the travel was taken up. All in all I didnt think "wow these are great", it felt like I had less brakes"
With set up d) tester said "it feels like there was a lot more braking power with less effort"

Surprise was that the performace was the opposite!!! the big bore MC gave a much firmer lever, so it felt good, but stopped worse as it generated less pressure in the calipers .... 12% worse stopping distance. the set up d) bike was still doing 30mph when the set up c) bike was stopped.....

Shows that the laws of hydraulic ratios is correct, but what the hand feels can be misleading to the brain.

So I have updated the XL sheet to show the GSXR ratios as well so you can compare the relative ratios in the data above to the various firestorm options.

I used the F4i calipers on the GSXR example as they gave 7% more piston are than the data I had for the GSXR 6 pots, and you can see that set up c) improved hydraulic ratio by about 7% over stock, and then adding big bore MC reduced it by close to 30%.

Below the GSXR stuff are just a look see at what you get with various options including the stock VTR parts.
first option looks to have great leverage, but I think the lever would come back to the bar before the biting point!
2nd option would be like the GSXR example set up d) very solid lever feel, but crap braking performance!
3rd option would be similar to 2nd option, but not as crap.

So lots of conflicting data, do you want brakes that feel powerful or ones that stop well?
suggest that you need to take care moving to a lower hydraulic ratio...........a big MC by its self may not be as good as it feels.
But new pads are a clear benefit

 

Thanks AMC, that is one of the most concise grouping of this type of info I have seen. Well explained too. Seems this is a big stumbling block for many bikers as I have argued this with many riders.

Brick wall lever travel does not compare to power or performance. No one seems to get this. Sorta reminds me of the guys putting stunt gearing and believing that means a faster bike.

 

So let me understand this. If just looking at Honda combos the only piston/calipers that out perform stock would be an all 600fi setup in terms of lever ratio 33 vs 35 and braking power, so I just wasted $50 on RC51 calipers!??