Rear disc conversion for 71 cb450?

[Garage_guy_chris]

Well like the title says im thinking of upgrading the drum brakes in the rear to a disc setup i have the ability to fab up a caliper bracket and do the hydraulic rear set, but....

Im not sure where to source spoked disc wheel from that will fit my CB and look original, im assuming i can pirate a newer higher CC CB? just need some advice on the donor candidate

 

[Gage Werke Composites]

Well like the title says im thinking of upgrading the drum brakes in the rear to a disc setup i have the ability to fab up a caliper bracket and do the hydraulic rear set, but....

Im not sure where to source spoked disc wheel from that will fit my CB and look original, im assuming i can pirate a newer higher CC CB? just need some advice on the donor candidate

My 76 CB750 SS has a rear disc set-up. Don't see why you couldn't mod something like that to work. If you need any measurements just let me know.

 

[Gage Werke Composites]

What my bike looks like:

 

[Swagger]

Easiest way would be to grab yourself a rear wheel from an XR/L650, KLR650 etc.
As you said, the rest will be cake

 

[Rocan]

or a rear wheel off a cb750f model should work.

i dont really see a point though... ebc pads and a good hub are plenty of stopping power....
you really dont want a super grabby rear wheel.

 

[Swagger]

or a rear wheel off a cb750f model should work.

i dont really see a point though... ebc pads and a good hub are plenty of stopping power....
you really dont want a super grabby rear wheel.

Yeah drums are awesome...that's why the really fast bikes like the R1 and CBRs use'm......oh....wait..........

 

[Rocan]

Yeah drums are awesome...that's why the really fast bikes like the R1 and CBRs use'm......oh....wait..........

i never said drums are awesome... if i thought that, i wouldnt have a disk front end on my cb350.

you get the maximum amount of stopping power from a wheel right before it locks. when it locks, you have very little braking power.

having a drum brake that can easily lock a wheel is plenty of braking power. hell, the real racers leave some air in their brake lines in order to have more control over the rear wheel.

a disk doesnt has better cooling ability as well as grabbiness. unless if you do some serious track days (not racing, must have drums for racing in most classes) then going to a disk is a waste.

 

[Swagger]

air in the line? Hmm....where to start........


nope, not gonna.

 

[crazypj]

First I've heard of deliberately leaving air in lines as well?
Rocan, its impossible to get consistency if there is air in the system, plus, it just sucks to have spongy brakes with excess travel at pedal or lever.
master cylinder sizes are easier to change to get correct 'feel'
saying that, nothing wrong with a rear drum, even though disc is generally lighter and has better cooling.
I used to get 80~90,000 miles from rear brake shoes, about 4,500 from front brake pads (dual disc CB550) its only there to steady bike, has to be on ground to work ;D
R1, GSXR, et.al. has a pretty small rear disc and 'cheap' caliper compared to front.

PJ

 

[Rocan]

First I've heard of deliberately leaving air in lines as well?
Rocan, its impossible to get consistency if there is air in the system, plus, it just sucks to have spongy brakes with excess travel at pedal or lever.
master cylinder sizes are easier to change to get correct 'feel'
saying that, nothing wrong with a rear drum, even though disc is generally lighter and has better cooling.
I used to get 80~90,000 miles from rear brake shoes, about 4,500 from front brake pads (dual disc CB550) its only there to steady bike, has to be on ground to work ;D
R1, GSXR, et.al. has a pretty small rear disc and 'cheap' caliper compared to front.

PJ

the amount of air wasnt significant... just enough to have a wee bit of spongyness instead of instant lockage.

 

[Fishhead]

the amount of air wasnt significant... just enough to have a wee bit of spongyness instead of instant lockage.

That's why you need a correctly sized master cylinder that actually works like it should. If you have "instant lockage" then something needs to be corrected (Smaller master cylinder).
Air in your brake lines? Never heard of that one ...