lynx-
Do you change the master cylinder as well as the caliper?
From a bit more reading... it depends. This is a good thread from someone doing it on a Thunderbird.
https://www.triumphrat.net/threads/nissin-3-pot-calipers-on-a-tbs.237187/The caliper pistons for the VFR800 were substantially larger than on the CBF1000. The CBF1000 has three 23mm pistons on each side for a total piston area of 2493 sq mm. This compares to two 27mm pistons each side on the stock TBS calipers, for a total piston area of 2290 sq mm. This is about a 9% increase in piston area, not substantial as far as the master cylinder is concerned. The VFR800, however, has three 25mm pistons on the left side, and on the right side it has two 25mm pistons and one 23mm piston. This gives a total piston area of 2870 sq mm, a full 25% more than the stock TBS calipers.
The upshot of all of this is that the stock TBS master cylinder, with it's 1/2" bore, would be completely inadequate to drive the VFR calipers. Generally they say for bikes with dual front brakes, a "piston area/master cylinder area" ratio of 15:1 to 19:1 is ideal, with 15:1 being on the firm side with less lever travel, and 19:1 being on the soft side with more lever travel. For bikes with single front brakes it's a little different, but I can't remember what a good ratio is. The stock TBS has a piston/master ratio of 18:1. With CBF1000 calipers the ratio would be 19.6:1, a little on the soft side, but not too bad. If you could get your hands on some CBF1000 calipers you could probably keep your stock master cylinder. However, with the VFR calipers and a stock master cylinder you'd have a ratio of 22.7:1. I never even tried running the stock master cylinder with the 3 pot calipers, but I would imagine if I had I would just about bottom the brake lever out before I could get maximum braking.
Also interesting as it looks like you can mod the 3 pot linked callipers to be single sided.
(pic from a different thread)
You are reading a single comment by @lynx and its replies.
Click here to read the full conversation.
hugo7
Thanks. That's really helpful.
Basically this is what I was looking into previously - and has prompted another investigation:
https://youtu.be/z14QeH7CMFk
A few people have done it on Triumphrat. The guy in the YT video is English though, which is good as there are things like the fork cartridge mod using one of the old yamaha(?) models that seems easier and cheaper to do State-side.
The caliper I posted looked the same as the YT, bar the extra nuts.
Also worth pointing out that I think the reason people like that caliper swap, is that it's better, without being so much better that you then have to think about extra bracing, etc. and keeps it proportional to the bike.