Modern alternatives to CB550 brake

[skimeister]

The front brake on my '75CB550 is as useful as braking with marshmallows. All components are fine by themselves (new pads, steel lines, rotor OK, no leaks), but the brake just doesn't "bite".
Aside from grinding the rotor, I am thinking about replacing the master cylinder with something from a more modern bike. Any suggestions on what will be a straight forward replacement?


Thanks!

 

[VonYinzer]

What size is the bore? If you look on EBay or at a salvage yard you should be able to get a modern master and matching caliper that could be fitted to your bike by way of a simple bracket on the fork lower.

 

[Swapmeet Louie]

You would get more "bite" out of a multi piston caliper than you would a new master. I realize it's easier to bolt something on to the bars than it is to adapt a caliper to your fork leg. But, if you want results. Thats where I would start. Though, I'm far from a modern component guru... Guru? haha

Lou

 

[scott s]

http://www.davidsilverspares.co.uk/CB500K0-FOUR-1971/part_123892/

I have this on my CB500 with steel lines and new pads. Works great and the price is unbeatable. Looks stock, too, if that matters to you.

 

[VonYinzer]

I really dont think you'll notice much of a difference with that MC compared to the Honda bit. Theyre basically the same.

 

[skimeister]

Thanks Scott, keeping the original look would be nice so that MC is a great option.

VonYinzer, when you say "simple bracket" is it actually simple or will it turn into a project?

 

[VonYinzer]

Its always a project... Haha.

It can be done pretty simply though, yes.

 

[skimeister]

Its always a project... Haha.

It can be done pretty simply though, yes.

Hah, true.
So any specific caliper / MC combo that would work best?
Thanks.

 

[Joksa]

http://forums.sohc4.net/index.php?topic=22383.10

I would try a master cylinder which is as small as possible without running out of travel. I am using a 14mm with dual disc setup and that is almost too small but the feel is quite good. For single disc 12mm seems to be quite safe choice, but I have no experience.

http://www.dotheton.com/forum/index.php?topic=8713.0
http://www.vintagebrake.com/mastercylinder.htm

 

[scm]

The front brake on my '75CB550 is as useful as braking with marshmallows. All components are fine by themselves (new pads, steel lines, rotor OK, no leaks), but the brake just doesn't "bite".

This is caused by (organic) pads with low friction coefficient and too big master cylinder.

Best regards
Sven

 

[skimeister]

This is caused by (organic) pads with low friction coefficient and too big master cylinder.

Best regards
Sven

Sven, If pads are suspect, I would definitely explore the new pads option before upgrading the MC and calipers. What pads would you recommend (ceramic / metal) ?Thanks.

 

[scm]

Well I don't know bout the Hondas, but the Yamaha SR500 frontbrake
gained a lot from the Goldfren sinter pads. Dunno whether they are
available for your bike, if not you might find a bigger one from another
bike and mill/file it to the suitable shape.
If you have steel braided hooses and your brake lever has a hard pressure
point and high force is needed you should also swap to a smaller master cylinder.

Best regards
Sven

 

[Roach]

question 1. has your master cylinder been rebuilt yet?

question 2. are you sure all the air is out of your lines?

you need to remember these are bikes will never have super bike braking ability. don't expect to be able to do stoppies

there are only 2 options to go to a more modern brake system

1. you do a fork swap with say cbr600 fork and then use a harley hub new rim that way you keep the look of the spoked rim get duel disks master calipers everything from the front end of a cbr and swap it over.....this fork isn't your only option....

2. do a duel disk set up on your stock fork

there really is no other options otherwise the guys over on sohc4 myself included would have done it along time ago.
you can thank Honda for that and there amazing braking technology from the 70's

 

[teazer]

Lots of great input. Remember that disks should be flat and bead blasted to remove all trace of teh old pad material which emdbeds itself in the disk surface.

Pad material makes a huge difference to initial bite. Some bite hard and others have a more gradual bite - and that's with pads of the same coefficient of friction. Some pads have higher friction than others.

You can change the master cylinder size slightly to get more bite or more feel - just don't go too far.

Old style disks and pads were low Coefficient of friction.

Modern multi piston calipers tend to flex a lot less than old calipers and more of the effort goes into making the bike stop.

Smaller diameter pucks move the effective diameter outwards and increase brake torque.

So many ways to change what you have.