Front Motorcycle Brakes for Rear Axle.

[Ryley]

Hello all, this is my first post on a forum like this. I'm doing an engine swap on a Black Widow gokart. I have a complete 2006 johnny pag raptor motorcycle. I will probably be asking lots of question on this forum but my first one is about increasing the braking power since I'm increasing engine power.

My plan is to use the front caliper off the motorcycle and mount it to the rear axle of the gokart. There are 2 major problems with this plan.
1: The diameter of the motorcycle rotor is almost twice the diameter of the gokart so the ground clearance will be 2inches. There are 2 possible solutions. One is to make another shaft for the brakes and the other is to use the gokarts OEM rotor and try to make up for the decrease in stopping power in the master cylinder.
2: I want to know what master cylinder to use with the motorcycles front dual pot single caliper. I need to use this caliper with a foot pedal so I will need help to find/size a new master cylinder since the motorcycle caliper is paired with a hand brake. The motorcycle doesnt have any information on the bore sizes.

some parts that might come in handy in the future

 

[itsid]

you shouldn't need a rotor that lage..
rotor diameter helps with cooling,
as long as you don't want the same speed as the motorcycle,
you should be good..
else swap to an internally cooled rotor with a matching caliper spacer.
Or frankly.. get a kart brake instead (racing kart, not fun kart)

You don't need a large bore master cylinder at all to make the calipers work,
the one on the bike will do just fine if you want to reuse it.
The rear one is simpler to adopt and what I'd suggest really
but the front one will work of course;
the lever can be pulled by a brake cable just as well.
cut it down, crossdrill the remaining handle stump and you'd be fine,
(well you may want to cut off the handle bar mount ... that's why the rear one is simpler to make use off on a kart)

motorcycle MC bores are usually tiny (6'ish to 9'ish mm)
almost any kart master brake cylinder will be larger anyways,
so nothing to worry about there tbh.

'sid

 

[Ryley]

Thanks for the information itsid. Knowing that makes things a lot easier for me. I will try to mount the front hand brake lever so it looks ok but if i can't i will buy this master cylinderThe reason I'm using the front caliper is because the rear brakes are drum brakes that are built into the rim so they are not usable in my case. Anyways I will post pictures of the brakes and pedals once make them

 

[itsid]

but the rear brake is still hydraulic, so it's master cylinder might be the easier option.

'sid