Rear brake master cyl for front brakes.

[sharky]

Is it possible to operate a pair of front calipers (R1) using a rear master cylinder ?
My doc has diagnosed tendonitos in my right hand:( (No not RSI [:I]).
This would explain why on long rides I can find it real painful to use the front brake lever.
So I'm thinking right foot to operate front brakes and a thumb lever on left bar for rear brake.
Obviously I can put a lot of force into the foot lever...but would it be enough ?
What size are rear cyl's anyway ???

[Pommy Chopper]

Most rear cylinders are 13mm or 14mm.
It's all worked out on bore x stroke, it's unlikely you'll be able to operate your front brakes with your rear cylinder as the amount of fluid shifted by the cylinder won't produce enough pressure to operate the pistons of your front calipers.
I have put front cylinders on a rear brake lever to operate front brakes when i did disabled conversions in the UK.

So it's possible, just takes a bit of work.

[chopaweeza]

There are 2 ways I've seen it done that were less painful on the wallet. The first was to use 2 rear master cylnders side by side with a custom linkage to the pedal with one working one caliper each. The other way Was the bloke used a Z1R Kwaka front master cylinder. These are a remote type that are operated from a cable. So he converted the Z1R master cylinder to take a cable from the rear brake lever instead. Both were on disabled/Injured riders bikes.

[sickboy]

Gday Sharky,I have a 1987 Moto Guzzi 1000 that has linked brakes ,that is one front disc and the rear disc is operated by the foot brake pedal ,70% of the braking force applied goes to one of the front discs and the other 30 to the rear disc and the other disc is operated by the front master cylinder, I have found that I rarely use the front brake except in "emegencies".Now I know 70's technology might not work to well with modern machines but like Pommy said anythings possible.

[loosebruce]

Might be worth investigating linked brake systems such as DCBS on Hondas or whatever it's called on BMWs.
BMs also employ servo assist and ABS on some models.

[Issues]

how bout hydrolic overide brake master from a trailer, PBR or similar. These are 5/8 or 3/4 bore from memory. These should be easily adapted n converted to remote res if needed

[pt]

maybe you could look at something the stunters use? i think there was a special M/C available that could have two lever inputs (i don't really know how to describe it as you can see).

maybe try stuntzinc?

[sharky]

Thanks for the ideas fellas.
The linked system from a h###a might have useful bits like a larger piston.
I'll certainly look into the stunt stuff as well.
Hopefully I won't need it but it is something I may be forced to look at.
I have picked up a wrist support that fits under my glove and moved the bars so my arm/wrist/hand is straight.
Fingers crossed :)