[Chevota]

I have been trying to search for an original Triumph master cylinder for the 72 forks I bought a while ago, but have come up short. It's a single disc setup. I was thinkin if I could figure out the bore diameter I could make something (maybe HD) work. Anybody happen to know what the bore diameter is on it, or know of what I could get away with?

 

[Tony the torch]

you can buy a 7/8" Magura M/C on Ebay that works great with the Triumph caliper and it is a much smaller and better looking set up

 

[Lee H]

just off the top of my head... I think the same company designed both the early triumph disc brakes, and the honda disc brakes of the 70s. I am reasonable sure a honda CB 550 or 750 front master cylinder will get you on the road until you can locate an original unit

I am not trying to endorse replacing triumph parts with japanese. I am merely stating that if the option is sitting at home or temporarily using a honda part... I would be riding

 

[Chevota]

Thanks Tony and Lee... Ill look into them both.

 

[billbrown]

i used a replacement set up for a Honda CB750K on my old boni with the same front end. It came from Z1 which is a vintage jap bike parts house, but it looked really good and i think it was only fifty-ish bucks.

 

[mblab]

FWIW. A stock honda 750 mc will work, but the bore size (18mm) is wrong for a Triumph caliper. You'll have no feel and barely any movement in the lever. Much better would be something in the 12-13mm range. Still plenty of leverage and much better feel.
Been there done that.
Mike