Yamaha TRX850 Enthusiasts Forum

can anyone help me please i am sure i have read on the forum that i can use my standard front master cylinder with blue spot calipers am i right or wrong HELP PLEASE

No problems at all with using the standard 5/8 MC with blue spots. Only reason to change from 5/8 to 14mm is because they complement each other.

Kevtrx849 wrote:No problems at all with using the standard 5/8 MC with blue spots. Only reason to change from 5/8 to 14mm is because they complement each other.

+1

you may find that the 5/8 mc lacks a bit of feel compared to the 14mm but it is absolutely fine to use

On this front, I'm still using the standard MC, which one do I use if I want to upgrade? Presumably an R6 of some description?

Cheers!

ANY 14 mm (piston diameter) Master cylinder will suit, the later Yamaha radials being the cheapest option, and best result for your bucks.

What would going to a 16mm bore do? More travel or less?

(Sorry for the thread hijack)

From what I understand it would be more powerful, but have less feel?

M.V. wrote:What would going to a 16mm bore do? More travel or less?

(Sorry for the thread hijack)

From what I understand it would be more powerful, but have less feel?

is my understanding as well

thank you very much i will eventually upgrade but for now i can carry on thanks again

I did notice much more feel and better power with blue spots and the 14mm caliper, so IMO it's worth getting a second hand 14mm caliper they are not that expensive.

If you want one pm me.

Used a 3/4" Nissin radial M/C in place of the 5/8" Axial Nissin on my TRX which is a Japanese home market model with Brembo calipers, this completely transformed the brakes - more power and much better feel. Best mod so far along with FCR carbs. M/C came from a GSXR1000. Will be keen to hear how you go with a 5/8" M/C.

Sounds counter intuitive, a bigger master cylinder should have less force at the caliper for the effort put in at the lever

Thats what I thought too, but it works! Maybe the leverage ratio on the piston is the answer?

I had a GSXR 750 radial master cylinder on my TRX, with stock calipers. The one thing I did notice was extreme lever travel if you let the pads get below half worn but it was plenty powerful enough though.
I still have it, fitted with a Pazzo lever and an accompanying clutch post and Pazzo lever too. I could be up for selling them if anyone`s interested?