Topic: 1981 Cb650C Master Cylinder

[Jbarth13]

Hi all,

The non-stock master cylinder on my 650C just isn't cutting it- the front has less stopping power than the rear with the lever to the bar.  I believe the problem to be the master cylinder.  Before I go buy an OE cylinder, do people replace these things with master cylinders off of other, more modern bikes for increased stopping power?  When commenting please recall that the 81 front brake system differs from previous years, and has dual discs.

Thanks very much!

[tomk1960]

Hi all,

The non-stock master cylinder on my 650C just isn't cutting it- the front has less stopping power than the rear with the lever to the bar.  I believe the problem to be the master cylinder.  Before I go buy an OE cylinder, do people replace these things with master cylinders off of other, more modern bikes for increased stopping power?  When commenting please recall that the 81 front brake system differs from previous years, and has dual discs.

Thanks very much!

Hey Neighbor,

Has your master cylinder ever been rebuilt?  How about the calipers?    I've overhauled many of these and it may just be time to disassemble, clean, and reassemble with new kits.  If you live nearby, I'll be happy to take a look at it with you and help get those brakes in good working order.

Tom
(Worcester, MA)

[RJ CB450]

Correct in the dual calipers needing a larger piston provided current one doesnt have air in lines.  Note.  The CB650sc has an even larger piston but looks identical.  It is bored out more for the dual piston calipers.  For the single piston calipers, would probably be too firm.