Topic: Front caliper+rotor on rear???

[puppytrax]

I've read here a couple threads on mounting dual disks on the front of CB550/750's, but has anyone transplanted a front caliper and rotor to the rear wheel?? You would in effect have the exact same caliper + rotor on both wheels, but with duals on the front...

I'm curious as to how to mount the caliper bracket...and make the pedal work...

(I seem to have leftover calipers and lower legs...why not give it a try, says I!)   

[Bodain]

Well I'm doing that very thing. Kinda sorta, but not on a Honda. I'm doing it on a 1974 Yamaha RD 350.
I imagine the same principle would apply to a Honda. The 74 RD has spoke wheels and with a drum on the rear.
I purchased a front and rear cast mags from a 77 RD 400 on Ebay. The 77RD 400 has rear disk brake. So now all is need to do is find and purchase rear master cylinder, caliper, brake arm. A bit of hacking, welding and grinding and it will be fine.

[Honda CBer]

the problem will be a possible difference in caliper and piston bore...

i.e. the rear caliper has a smaller bore thus requiring a smaller amount of fluid to actuate, and an appropriately sized master cylinder... when you mount the larger caliper to this m/c, more lever travel is required to actuate the brakes... as a result, brake performance will suffer... also, pushing the lever too far could ruin your m/c, requiring rebuild... you need specs, brother...

math anyone?

[puppytrax]

the problem will be a possible difference in caliper and piston bore...when you mount the larger caliper to this m/c...

"What we have heah...is a failure to communicate..."

What I am thinking of doing is mounting an entire single disk CB500/550 OEM front brake system on the rear swingarm...rotor, caliper, master cylinder, lines...and then two OEM systems on the front, off one master cylinder...there would be no mixing of rear parts; I would mount the caliper much the same as on the front fork (using the same aluminum bracket), and modify the front brake lever/master cylinder so that the pedal would activate it...using all original parts from a single donor (which is sitting in my celler)...

Yes, the [rear] M/C would need cutting & machining; I would probably use a stock front wheel with a special adapter for a sprocket on the rear; and I would need to fab a linkage from the brake pedal to the remounted M/C...

But I'm wondering why no one else has tried this already...I'm sure someone has...and either found out why it won't work, or has made it work...

[StevieMac]

But I'm wondering why no one else has tried this already

Because it seems like a hell of a lot more work than just adapting a wheel that already has a disk AND a cush drive/sprocket attached 

[Noel]

Isn't it bad enough to have a crappy brake on the front of the bike? Why would you want to add a crappy brake to the back too?

[puppytrax]

Because it seems like a...lot more work...

I don't mind work...and I already have these parts...plus a lathe, mill, welder, etc...   

[puppytrax]

Isn't it bad enough to have a crappy brake on the front of the bike? Why would you want to add a crappy brake to the back too?

... ...Now that is funny!!!   

[ProTeal55]

I would be curious to see this come about - if you can get it to work...

[puppytrax]

I would be curious to see this come about - if you can get it to work...

I just noticed from your pics in another thread that you have dual disks on front...I seem to recall reading an impossibly long thread where you described great problems installing them...

Do you really want to go through all that again??   

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The cush hub comment was interesting...I've always thought of the cush drive as a convenience rather than a must-have...but looking at one of my spare rear wheels, it would not be all that hard to make an aluminum plate for the rotor to bolt to (replacing the shoes + OEM brake backing plate), and retain the OEM hub & sprocket...might be able to make it a bolt-on...

As for adapting an existing wheel + rotor, all I've seen are solid wheels...did Honda ever make a disk rear hub with spokes??   

[StevieMac]

You NEED a cush drive.  You'll beat the crap out of your tranny without one.

[ProTeal55]

I just noticed from your pics in another thread that you have dual disks on front...I seem to recall reading an impossibly long thread where you described great problems installing them...

I had lots of little issues getting everything working properly, this is true...

Do you really want to go through all that again??

No , Not if someone paied me.
I never said I wanted a rear disc, I said I would like to see SOMEONE ELSE get it to work.
I am done with big projects on this bike...