Topic: What caliper is this?

[derelicte]

The speed bleeder I ordered was the wrong size.  I email him and say, "wrong bleeder."  He emails back "wrong caliper."  Sure enough this doesn't look like 750 calipers I see on ebay, but it was mounted up to my bike when I bought it on what looks like the stock bracket.  1974 cb750k

[scottly]

What is the bore diameter?

[Scott S]

 Looks like a 350/360/400/450/500/550 caliper. That same caliper was used on the twis and the fours.

[scottly]

The K7/8 caliper looks similar to the smaller bike calipers, but has a 42.7mm bore instead of 38mm.

[farmertom]

That fits a '77 cb750K or a '76 thru '78 cb750A according to what's in my garage...

[cobra]

or a 76 cb750f. these are good calipers for twin disc conversion, as they can be left or right,

[fmctm1sw]

I vote small four 350F/400F.  I believe the mounting bolt spacing is different for the small fours and the larger bikes that had that same look though.  I think '73 was the last year the 750 had the finned style caliper.  Of course, it may be possible to take the whole caliper arm off a small bike and put it there as well.  As already mentioned, what's the diameter of the piston?

[754]

76 is last year of finned caliper... early F, A and both 77/78K used smooth ones.

[Blackandsilver]

Yeah looks like 550/500 to me. The disk and arm and caliper will all be slightly different than the 750 ones if that's the case. Smaller disk. Lower arm. They all bolt to the same forks though. And I'll second that the 550 caliper set up works better for a twin disk.


Win some lose some, it's all the same to me.

[derelicte]

Thanks for all the responses - measured across the piston if that's okay and looks to be around 43mm.  So a 750F?   

[scottly]

All 750F calipers aren't the same. When shopping for parts, play it safe and call it a 750 K7/K8 caliper. By the way, consider it an upgrade over the earlier caliper, which was 38 mm. It will provide slightly more braking force, for the same pressure on the hand lever.

[Don R]

F0, F1, K7, K8. Maybe others. I believe it fits the same bracket.

[derelicte]

Great.  Anyone know what size speed bleeder?  Seller is nicely offering an exchange.  Lost the original bleeder screw.

[scottly]

I don't know for sure off the top of my head, but it may be 6 mm?

[derelicte]

Turned out to be a 7 x 1.0 thread.  Got the correct one coming in the mail.

Still have the piston seal I ordered thinking I had a k4 caliper - $10 shipped to anybody interested.  Unopened oem.

Thanks again guys.  This will work alright with my presumably stock master cylinder?