Help required by overhauling brake calipers

[raceron]

I'm Ron, living in Belgium and having some problems finding the correct parts for my brake calipers of a 1977 Gs 550. I'm looking for a suitable seal and
and dustseal (parts 2 and 3 ) (hope this is the right translation).





Looking on the internet it's easy to order original parts, so that is what i did. After ordering new parts I received 42 mm seals, but my pistons are only 38 mm. My calipers are from the manufacturor ASCO and looking at the technical drawings on the internet they are the exact ones installed in 1977. Still there is the difference in measurement, can anyone help me by letting me know where to order the right size?
Thanks a lot!

[Big T]

There's lots of places like Bikebandit you can order from, but I don't know how they'd check the size.

What about your local Suzuki dealer? If the parts are available, they can order them in and you can check them.

Are you sure the calipers are original?

One of our 550 guys will have to verify the size of the pistons to confirm the correct size.

[hampshirehog]

Ron, you've got the right calipers there - your pistons should be 38mm. (though with wire wheels on a 77 you should have a single front disc so someone has sensibly upgraded).

Best place I've found is Worlds End Motorcycles - wemoto.com. (Being in the UK they are at least 'local' on the 'world scale' and you won't get clobbered for any import duty). Their parts are pattern but decent quality unlike a lot of rubbish pattern brake parts around.

They do the stainless pistons for your bike as well - an upgrade defininitely worth doing as that's rusty pistons banished for ever. Have a look at:

http://shop.wemoto.com/pictures.dyn?u=1915451qqq5772695

With the £ slumped against the Euro it might be an especially good deal for you at the moment.

And stick some more photos of your bike up - I'm looking for inspiration for some 550 mods and there's bound to be others who'll be interested as well.

[Matchless]

Looking on the internet it's easy to order original parts, so that is what i did. After ordering new parts I received 42 mm seals, but my pistons are only 38 mm. My calipers are from the manufacturor ASCO and looking at the technical drawings on the internet they are the exact ones installed in 1977. Still there is the difference in measurement, can anyone help me by letting me know where to order the right size?
Thanks a lot!

Hi,
Go to you local motorparts store and buy a set of rear caliper seals for a BMW318i, 320i or 325i they are the exact size for the seals and a full set of rubbers will be very cheap, only use the 38mm seals as the dustcovers are not compatible.

[Suzuki_Don]

Original caliper pistons are 42mm

Ron I have a '77 GS550 and I have just pulled the piston out of the ALSCO caliper and the piston measures 42.81mm across the diameter. If you have 38mm ALSCO calipers then I don't know what they are off, but it's definitely not a '77 GS550 with wire wheels. The only 550 to my knowledge that had twin discs (and therefore the right lower fork leg with the lugs to mount the extra caliper) was the Katana. So I don't know what model the forks are off, but I don't think it is a 550. So you need to work out if you can where the forks came from and then you will be on the right track. A better picture of the front end would help us to identify things for you.

[raceron]

Thanks for your replies. I got a tip from a guy who recognised the calipers as the same as mounted on a '76 GT 550.
These calipers are also in 38 mm instead of 42, so I hope when ordering those seals it will fit!

[hampshirehog]

Ron I have a '77 GS550 and I have just pulled the piston out of the ALSCO caliper and the piston measures 42.81mm across the diameter. If you have 38mm ALSCO calipers then I don't know what they are off, but it's definitely not a '77 GS550 with wire wheels. The only 550 to my knowledge that had twin discs (and therefore the right lower fork leg with the lugs to mount the extra caliper) was the Katana. So I don't know what model the forks are off, but I don't think it is a 550. So you need to work out if you can where the forks came from and then you will be on the right track. A better picture of the front end would help us to identify things for you.

Don, all the UK 550s except the early wire wheel ones had the twin disc set up. I've got a big box of old calipers, (mostly verging on scrap but I'm loath to bin them) and they are all 38mm diameter. The later caliper pistons (around 1980 onwards, with the square pads) are still 38mm but about 2mm longer.
I'm guessing that maybe you guys and the Yanks got a different set up to us 'old world' chaps. Maybe the Japs thought your roads were better and didn't need to brake as hard as us on our crowded roads

[Suzuki_Don]

Don, all the UK 550s except the early wire wheel ones had the twin disc set up. I've got a big box of old calipers, (mostly verging on scrap but I'm loath to bin them) and they are all 38mm diameter. The later caliper pistons (around 1980 onwards, with the square pads) are still 38mm but about 2mm longer.
I'm guessing that maybe you guys and the Yanks got a different set up to us 'old world' chaps. Maybe the Japs thought your roads were better and didn't need to brake as hard as us on our crowded roads

Hi Thanks Wally. Yes I was just going off the Suzuki parts books that I have for my '77 550 and the online fiches. Looks like I was barking up the wrong tree completely. It looks like they used different stuff the world over then doesn't it.

On another slightly different issue would the smaller 38mm piston giver better leverage (stronger braking) than the 42mm piston using a single disc for example.

Thanks for the correction, it's always good to be learning some new item of information.

[raceron]

Today I received the brake parts of a GT 550, and it fits superb! Thanks for your replies and tips!