modern brake calipers

[jcsnu21]

Going to be swapping out the old crap brake setup for a modern disc and brembo 4- or 6-piston caliper. Has anyone done something like this and have it documented? What pitfalls or issues did you find?

jc

[Re-run]

What bike is this on? I know these old systems are not super but sometimes a simple rebuild with braided hoses can make a big improvement.

[jcsnu21]

1973 cb750. from a heat dissipation standpoint I'm not keen on the old setup. perhaps just swapping out to a slotted/drilled rotor would help, but overall its an inefficient design by today's standards

[Re-run]

Of course it is inefficient, it was designed back in 68. but it is not as back as you think. Yes it IS a single disk and so is limited. There are a couple things you can do.
A steel braided line will help a lot. You can get one from galfer, helusa, or even a local hydralics shop. No matter what you do, get one of these.

Rebuild the caliper. They work pretty well but using DOT 3 fluid attracts water which then causes corrosion and binding.
Swap the front end. You have a couple options here. The early goldwing gl setups were a very common mod.
They still used spokes and had a dual caliper setup. Just transfer the whole front end, forks and all. I am not sure if you need the triple tree though.

the other option is the F2/3 front end. It is possible to use the spoked wheel still but I think you have to use the F axle but I am not sure.

Your final option would be to get a second disk and caliper for a K bike and mount it on the right leg. For this you will need the cb500/550 speedometer plate to swap out the 750 one. The bolts for the current rotor will need to be longer. You will need all the same hardware to mount the caliper plus some washers to use as spacers.

I have not done this but can describe, fairly well, the procedure.

I have not heard of someone fitting a brembo but a dual set up, even using this old stuff, works very well.
Are you going to do stoppies? No but then the weight of the bikes would not allow that with the forks.

So read this and decide what you might want to do. Check ebay just to get an idea of parts cost and we can go from there.

[jcsnu21]

I'm pretty dead-set on modern calipers, from a power, safety, and looks perspectives. I would also prefer to not use a new front end.  I would think that a single 4-piston caliper from Brembo or Nissin would be more than sufficient compared to the current setup, and I guess the only issue would be finding a used set where someone was willing to part with one side. I was thinking that if I could find a narrow enough caliper, maybe even off an MX bike, that I could CNC a new bracket without the float and mount it.

No stunts for me, just building a cool cafe. Dual front disc would be good looking but I'm assuming you're talking about using the original brake caliper setup?

[Re-run]

Yes the dual uses the period parts. See if you use the F2/3 forks and lowers, you can use the calipers from a 1982 ish model that ARE dual piston.

Either way though, if you do anything dual or newer caliper, you will need to replace the master and mod the brake switch. I suppose you might be able to keep the pressure switch if your bike has it.
but the old masters do not move enough fluid. An old gold wing or F2/3 master does though.

I have not seen either nissan or brembo make calipers for these bikes. I am sure it can be fitted but you will most certainly have to make a custom mount. You MAY be able to use the stock brake mount arm but you will most certainly have to mod it some and you will probably want to reinforce it.

I wish I could give you more info. Maybe if someone else happens on this post, they might shed more light.
If you know people with honda 750 bikes, maybe direct them here. We are a very small forum and so not much available info yet. If we can get more people, we can get better answers for questions such as this.

[Pickandpray]

i mounted a dual piston caliper from a vf500 mini-interceptor on my 80 cb750 and a new master cylinder from ebay for some yamaha.

The caliper allows me to use modern HH pads and the master cylinder is 1/2" (12.7mm) which is smaller than the factory 14mm master.  

The combination of dual piston calipers with braided lines and *smaller* master cylinder makes for a nice modulation and decent braking and I haven't even bedded the pads yet.

[buttcan]

Have you considered a Goldwing front end ? I believe it is the the 76-77's that are an even swap and have spoked wheels with dual calipers. Just a thought.

[J Smitty83]

Does anyone know if (or has done) the GL 1000 front end conversion works on a 74 CB 750? And if so, what is all involved with that?

[Re-run]

I think the easiest thing to do is just get the whole front end including the tree and swap it that way. That would be the easiest.