correct pads for my calipers?

[superawesome]

Hi,

since swiss legislation does not allow saltymonk's twinpot upgrade, I bought some used calipers to at least upgrade from those tiny round brake pads to pads with more surface area (1978 GS1000E).

I bought these calipers, but the seller was not sure from which model (many GS' used those between 81 and 86 I think), but they should bolt right on (i.e. not from an L model).



Looking at the different fiches it seems I need those pads


...but some GS models also have those...

...but then I guess those fit into the calipers with the rectang...ly shaped casing. But it is quite impossible to check all the fiches..

Can anybody confirm the MCB501 ones fit my calipers?

[Grimly]

They look sufficiently different to ther versions I'm using (which take the 509) to suggest they'll be the 501 version.
Fit a decent modern span-adjustable master cylinder, too.
I recommend the Deauville 5/8" from 2001-onwards.

[superawesome]

Thanks Dave. Is it strongly recommended to replace the master cylinder? Mine seems to be fine, and since I have a vintage plate everything should look more or less stock.

Anyway, process is delayed since the pistons were pitted at the rim (which I made worse by trying to pry them out). Bottom line is they are pretty much useless now.
2020-10-19 17.46.22.jpg
I ordered some new ones with seals and everything at brake-masters.com. Those calipers I got have the early 36x38mm pistons (as opposed to the 38x38mm of the newer versions), but the sales guy said, they have them.
Delivery is stuck in Swiss customs at the moment, but I hope to get them this week.

[Grimly]

You can keep the original m/c if you want, there's nothing particularly wrong with it.
It's just that the later m/cs tend to have better ergonomics, and I've developed a preference for the Deauville one, which doesn't look out of place on a 40 year old bike. Same bore size, so if you find the stopping power satisfactory, there's no downside.

On a related note, on my XS650, I overhauled the standard calipers (surprisingly little wear for the mileage they've done) and went from a factory size 11/16th inch (17.5mm) m/c down to a 14mm m/c from a Kwack.
The result was a superb set of brakes, but there was too much lost motion at the lever, caused by the slight rocking in the calipers.
I went to the trusty Deauville m/c (5/8th inch - nearly 16mm) and the result is perfect - still got two-finger braking with no lost motion.

[Nessism]

Those calipers take the 501 pads. Be sure to check the sliding pins and grease them with heavy moly caliper grease.

The master cylinder should have a 5/8" piston. If it's not leaking it's most likely okay. I'd change the brake lines while you are cleaning everything up. Braided stainless is good.

[Steve]

I did not see any "pitting" in that photo.

Yeah, I saw some damage around the edge of the rim, but that will not have any impact on operation.
Just file the ragged edges smooth and put them back in.

.

[roeme]

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Anyway, process is delayed since the pistons were pitted at the rim (which I made worse by trying to pry them out). Bottom line is they are pretty much useless now.
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(...)

I agree with Steve, that's cosmetic damage.

[superawesome]

I agree with Steve, that's cosmetic damage.

Cool, thanks guys.