Front master brake cylinder

[Edmaddox]

Good morning I have been going thru my brakes and am wondering if anyone has tried randakks 5/8 bore custom front brake master?

[Edmaddox]

Shame on me I forgot this is on a 1980 gl1100i

[Whiskerfish]

Yea works very well. Paired it up with some freshly rebuilt calipers and new SS lines and it is a huge improvement over stock.

[Edmaddox]

Thanks wiskerfish already got the stainless lines an rebuilt calipers , orders a cheap front master and it leaks.

[Whiskerfish]

Been running one for I don't 6 years or so now. I have flushed the fluid once or twice just as a scheduled maintenance otherwise not touched it and it has worked flawlessly.

[Edmaddox]

Ok so here is a ? Randakk says it’s all about the ratio of master bore size to caliper bore size.(I guess in some things size does matter). Anyway whe I measured oem bore size it looks real close to 5/8 “, wich I believe is what his fancy one is. So what am I missing?

[DUGG]

If your's is 5/8 you'll want to go with the 14mm/9/16 to improve stopping power.

[SnoBrdr]

If your's is 5/8 you'll want to go with the 14mm/9/16 to improve stopping power.

Or you can go to dual disc front calipers.

[Old Fogey]

If your's is 5/8 you'll want to go with the 14mm/9/16 to improve stopping power.

Or you can go to dual disc front calipers.

14mm good for the single piston calipers, but to get some decent braking keep your current master and find a pair of dual piston calipers from an 82 GL1100, which is what I think SnoBrdr meant. Straight swap.

[SnoBrdr]

If your's is 5/8 you'll want to go with the 14mm/9/16 to improve stopping power.

Or you can go to dual disc front calipers.

14mm good for the single piston calipers, but to get some decent braking keep your current master and find a pair of dual piston calipers from an 82 GL1100, which is what I think SnoBrdr meant. Straight swap.

Mine are from a different year but that is what I mean.

Thanks for clarifying it.

[BlueThunder]

On my '77 GL1000, I replaced the stock 11/16" MC with a 5/8". Then replaced the stock hoses with stainless steel braided brake hose. Replaced the T under the headlight with a double banjo at the MC. Made a world of difference. Now if you really want these bikes to stop on a dime, use EBC/V (semi-metallic aka semi-sintered) brake pads. You won't be sorry and amazed at how well these bikes can stop. Oh, BTW, I kept the stock single piston calipers.

[DUGG]

That brings up what kind of stopping power do you get if you have a 14mm master, ss hoses and add dual piston calipers?

[robin1731]

That brings up what kind of stopping power do you get if you have a 14mm master, ss hoses and add dual piston calipers?

It's all relative. Asking that will never give you a true answer. You would have to ride bikes with all the different setups to get a true indication of how each one works. one guy could say his setup is great and someone else could ride it and say it is just so-so.

.

[DUGG]

With nothing more than a butt skid pad it is all of coarse subjective. But It seems pretty well documented here on the forum that SS hoses improve braking, a smaller bore m/c improves braking and dual piston calipers do also. Seems like all three combined would be the superior set up. But maybe the 14mm m/c and dual piston calipers don't work together.

[BlueThunder]

If you go too small then the lever must travel further to move the pistons. 5/8" is a tad larger than 15mm. 14mm IMHO gives a bit more lever movement than I like.

Throw on a set of EBC rotors and you'll have fantastic brakes. Nothing short of a modern brake system will get you any better.