Rear brake.....

I completed a swingarm swap out on my 1994 KZP1000 a while back. One of my concerns with the swap out was the rear brake. The swing arm came from a 03 04 ZX636, along with the ZX rear wheel and brake assembly. The rear brake caliper from the ZX636 is considerably smaller than the stock 1994 KZP1000 caliper, as is the rear brake disk. My original rear brake worked well.

I've noticed ever since I completed the swap out, my rear brake does little or nothing to slow or stop the bike. I have tested the rear brake by simply applying the rear brake only... to slow or stop the bike but, I might as well not have a rear brake at all. One other question I have is, do quality brake pads out perform low cost pads? I bought cheap pads online, wondering if I need to try high end pads?

Any ideas would be appreciated.

If by 'quality' you mean sintered metal, then, yes, they out perform. They also chew through rotors pretty quick. It's a trade off.

Why were you unable to use the old caliper and rotor? Because you used a new wheel?

Yah, I used the ZX rear wheel........

Copbike1000 wrote: Yah, I used the ZX rear wheel........

Did you use the ZX master cylinder or the KZP master cylinder? They may have a different bore/stroke.

I had a zx6r, look at the 2 huge front rotors, thats your brake. The rear just keeps the bike straight for the most part.

Consider this. You put the rear brake from a ZX636 on a KZ1000-P. The ZX636 weighs 377 pounds. The KZ1000P weighs 705 pounds minus whatever you removed. The brake on the ZX636 was engineered for a bike that weighs 377 pounds. Have you trimmed more than 300 pounds off the KZ1000-P? If not, this could be a factor. Ed

Was the 636 designed for sintered metal pads? If so, that may really make a difference. As already mentioned, the KZ master cylinder may not move enough fluid, but I kinda doubt it.

Because sport bikes are quite nose heavy, their rear brakes tend to be pretty small. Even with optimal parts, you may have to adjust your braking technique.

I used the KZP master........

Good point. I did remove all of the "COP" stuff off of the bike. Don't know what the total amount of weight removed would be.
I removed miles of unneeded wiring, removed KZP fenders, handle bars, dual exhaust, center stand, bulky seat and pillion pad, cut off frame loops that supported foot boards. I am running ZX 636 wheel which is much lighter than the stock KZP rear wheel. Swapped swingarm from very heavy KZP swingarm to ZX636 swingarm. All said and done, I think I removed a substantial amount of weight on my KZP. Other than the brake issue, the bike runs better than anything I could have hoped for.

I think I will go with sintered pads and see what that does. Worst case, I would attempt to reinstall KZP caliper. Thank you ALL for your ideas and advice.

I think I used my zx6r rear brake when I first got the bike, found it didnt do squat.....used it on an incline at a stop ans when I had to do an emergency brake. 99.9% of the rest of the time it was all front brake. They are a different animal. IIRC, the front has twin 4 piston calipers and the rear is a single piston. That should tell you something.

My vote is not the size of the Zx6 caliper but the size of the KzP M/C (14mm) compared to what the Zx6 M/C (1/2" or 12.7mm) is.

Later, Doug