I was picking up some heads from the bike wreckers yesterday and found some brake calipers off a big kawasaki bike. They were 4 piston and are about 6" long by 3" wide.
I am wondering if anyone has done or knows of a conversion using bike calipers. These looked about the same size as the KAD 4 piston calipers. They bolt together with 4 bolts and have a spacer in the middle to suit the disc thickness

_________________
Research is the difference between speculation and investment. Anyone who copys some one else will always be second
www.minisprintgt.com

I don't think they'd be practicle in a mini, certainly not on the front.
They're designed to stop something much lighter than a car, so whether or not they are 'heavy duty' enough is what I'm wondering?

TRY IT go on YEAH if it works tell us how hard it was to finish.

David i`ve been thinking about doing it for years & years but all the bike FRONT calipers seem to have that silly braketry angle with the lugs offset all funny & if you face yours up to a mini hub you`ll see what i mean

the rears are a better lug combination/angle but are usually p!$$y small so would probably only suit fitment to the rear of a mini, which wouldn`t be a bad thing tho

go for it & let us know how you go,,, get it all working good & then sell me a pair of your brackets

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

The material used in the mounting lugs will be the limiting factor here.

The lugs mounting my R1's calipers to the forks are 6mm thick to pull up a 150kg motorcycle to the point where the tyre breaks traction and slides.

The lugs mounting a standard set of calipers to a Cooper S disc brake hub is 13mm (in steel instead of ally) to pull up a 700 kg car with a tyre twice as wide.

These certainly don't look strong enough for the application.

_________________
SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

The S calipers and swivel hubs are actually grey cast iron not steel- rigid yes, but it's not as strong as you might think.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I've thought about it too, but baulked when I looked at the mountings... they're designed to stop a 150kg bike, with a 100kg person on it... but from 300kph, not from 150kph.... maybe?

_________________
did I tell you that I won a trophy?

Also think about the clamping force on the caliper itself. You would need a lot more pressure on the pistons to stop a Mini. (I wonder what the line pressure on the bike would be?)

I think that the caliper may split before the mounts break.

I havent seen a vented rotor on a bike, unless you were goin to stay solid the caliper wouldn't have enough space for the rotor.

you can make a thicker spacer to suit the disc - same as for the metro and the aftermarket (minisport etc.) calipers

_________________
did I tell you that I won a trophy?

That is what Holden did with the XU1 calipers (and the Bathurst Monaros before that) They just got a bit of plate and cut it to shape and drilled some holes, easy peasy!

These calipers have 2 x 12mm holes cast into oneside of the body about 10 -12 mm thick. The hole set-up is same as mini and most dual piston caliper. The front forks had a triangular casting on the forks to bolt caliper onto. The bike disc was app. 6-7mm thick and about 220mm dia but I have some 8 1/4" ventilated discs off a diahatsu that I was going to machine down to 8". Then make a new wider spacer plate with same position for "O" rings for cross over sealing. There are 4 x 8mm cap screws thru body to bolt together
The pistons are 1 1/2" [have not measured accurately] and the pads look almost the same as the suzuki ones that I use. They are same as Honda civic. The fluid line into the caliper is one one side and is 10mm X 1 mm pitch. All the fluid porting is internal.
They look quite a solid caliper and Micheal says that they are made from a magnesium alloy. One reason the bike boys do not use them is that they are too heavy and bulky for race bikes and they have lighter 6 piston ones. He was going to find some Honda ones that come off the big touring bikes that he says are similar.
It's just another crazy idea, I cannot help it but it might be a cheap way of making some 8" vent 4 piston brakes.

_________________
Research is the difference between speculation and investment. Anyone who copys some one else will always be second
www.minisprintgt.com

Out of interest, was it a modern kwacka, or one of the old heavyweights?

_________________
SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Someone told me years ago they used four piston aftermarket callipers designed for a Harley on their Mini. But it may have been rubbish.

_________________
Brett Nicholson
Greendale (near Ballan) VIC.
1971 Morris Mini Moke
1966 Austin Mini
1965 Morris Mini Traveller
1973 LR Series 3 88
2007 LR Freelander 2

I think that it is about a early 90 model kwacka 1000? there was no eng just the frame

_________________
Research is the difference between speculation and investment. Anyone who copys some one else will always be second
www.minisprintgt.com