IMA Thumb Brakes

[Nelso]

I want one really bad, but I $899 for the race version is going to put it out of reach for me. What's the difference between the base and racing kit models?

[Marshy]

What's the difference between the base and racing kit models?

The main question is whether you want to keep the foot brake or not. If you do want to keep it, you need some sort of junction valve to allow the two master cylinders (at the thumb and at the foot) to operate the brake independently, and for the line to pressure properly without the fluid just flowing backwards through the other circuit.

The Base kit doesn't come with a master cylinder at all. The idea is you mount your OEM one on the thumb brake, and do away with the foot brake altogether.

The Racing kit comes with one IMA master cylinder, which has a built in junction valve. This IMA m/c is mounted at the foot pedal, to give the foot brake the junction valve it needs to operate both thumb and foot. The OEM m/c (without a junction valve, obviously) gets moved to the thumb lever mount to be operated by the thumb lever.

You're pretty handy, Nelso. Junction valves aren't that tricky. I don't think it'd be too hard to buy one and fit it to the OEM rear m/c. I'm not going to; I'm buying the full kit. But if you're on a really tight budget, I'm sure it's doable. Or get rid of the foot brake altogether and buy the Base kit, and you're ready to go!