Front Brake Caliper Change 1979 to early-80's

[Guest]

Suzuki changed the front brake calipers on most (all?) the GS series starting in 1980. The rotors changed along with the calipers. Anyone have any experience/know if this resulted in improved braking at the front? They must have done this for a reason... Thanks!

[hampshirehog]

Yep, much better front brakes. Which bike are you thinking of doing this to?

[tkent02]

The calipers are much better, the discs are drilled and a little bit thinner and lighter. You get a lot more braking for a lot less finger pressure, and no more squealing. Everything just bolts on to put the later stuff on the earlier bikes.

But if you want better brakes consider the Saltymonk upgrade, it really works well.

[hannibal]

Do the 80s bikes still use single piston calipers on a lighter, thinner (and larger?) rotor?

[Skowinski]

Thanks guys, it's a 79 GS1000 and I'm going to the 80 rotors and calipers. Figured out there were a bolt-on swap, and getting good prices for the parts in really good condition. The looks of the discs themselves are an improvement over the big dinner plates on the 79, and I figured the brakes would be better, so that's good to know.

Thought about the saltymonk upgrade, but this is an easier upgrade at the moment, and it might be enough to satisfy me.

[Skowinski]

Actually - one further question - did Suzuki make changes to the bore/volume in the master cylinder going into the 80's brakes?

[Nessism]

A few information tidbits...

Dual disc bikes get a 5/8" bore master cylinder, and single disc bikes uses 14mm. This did not change over the years with GS bikes.

The early dual disc rotors are the same size as the later rotors. The single disc bikes disc is larger than the duals.

There are a couple different types of caliper Suzuki used starting in 1980, as referenced in the different pads they took.

[tkent02]

Also you CAN use the single caliper master cylinder with two calipers, and it gives better braking. It's a simple mechanical advantage thing, smaller cylinder moves less fluid but at a higher pressure. Since it doesn't move as much fluid, if your brake lines are old and stretched or if there's is air in the system it won't work, but if you are using braided steel brake lines and bleed them well, you get more braking for a given finger pressure with the smaller master cylinders.

[Grimly]

While there is definitely an improvement with the '80-on brakes, you still have to keep an eye on their Achilles Heel, which is wear in the sliding pins and the sockets the pins slide in. The slight amount of wear just get worse and eventually renders the caliper carriers scrap, as there's not much material left to put a sleeve in (although someone might try it). However, there are still plenty of low-mileage calipers and carriers left out there, to have at it. When fully rebuilt, these '80-on brakes aren't like Superbike brakes, but with a decent set of Carbone Lorraine or modern semi-sintered pads in them are perfectly capaple of stopping a battle ship like the GS850 on a dime. If you're not doing heavy miles, the wear takes a LOOOOONg time to show up, so it's nothing worth worrying about. Just find low-mileage parts and rebuild, and you're good to go for another 20 or thirty years.
On balance though; if I'd known of Salty Monk's Kwack conversion before I'd started buying in parts, I think I'd have gone down that route.

[Skowinski]

Thanks for all the comments and information! Looks like I have a good set of 80 calipers and discs. Going to rebuild and put in some good modern pads, already have braided stainless brake lines, and am looking forward to some better brakes on this heavy beast!

[limeex2]

Also you CAN use the single caliper master cylinder with two calipers, and it gives better braking. It's a simple mechanical advantage thing, smaller cylinder moves less fluid but at a higher pressure. Since it doesn't move as much fluid, if your brake lines are old and stretched or if there's is air in the system it won't work, but if you are using braided steel brake lines and bleed them well, you get more braking for a given finger pressure with the smaller master cylinders.

EX500 has 1/2 bore. Not sure of year. Sorry.