Four piston Brembo conversion

[John M]

Here are two shots of my new  (old ) 4 pot brembo caliper. A easy and inexpensive upgrade from the 2 pot brembo's. I purchased a used 4 pot caliper from a 1999 oilhead rt . Right side caliper for my left side fork leg since the oilhead calipers are mounted behind the forkleg.
Works much better than the original 2 pot caliper ( stronger braking and better feel )  Best wishes for the holidays John

[Bob_Roller]

What size master cylinder do you have ?

[John M]

My master cylinder is 14mm

[tvrla]

I wonder what it would take to mount those on the earlier twin shock bikes?

[John M]

As long as the 2 pot caliper Brembo caliper mounts are 108mm o.c.
I think it will mount with a little milling of the mount ears. I don't know what size master cylinder the twin shock bikes have typically, my 14mm master cylinder works very well with the 4 pot caliper and my single disc. The feel is better ,my brake felt a little wooden and when it bit it was not as easy to modulate.

[tvrla]

There are differences because the twin shock R65 takes a unique caliper that's different than any others. I'll have to take a measurement, but doubt it'll work out to 108mm. Somehow I don't expect it'll be that easy!

[Julio A.]

Did you have to remove material from the side that faces the wheel?
I'm glad yours worked out well.

I've been trying to do that conversion for ages on my twin shocks.  
Too much modification; I gave up.

[John M]

Hi Julio, the material was removed from the outside of the mounting lugs of the caliper(away from the wheel) this moved the caliper out from the wheel so it centered properly on the disc.

[tvrla]

Yeah, that's one of the differences between twin shock calipers and monos - the twin shock caliper is sandwiched between the bolt head and slider mount, whereas the mono has threaded mounting holes in the caliper which means the slider mount is sandwiched between the bolt head and caliper.

[Milo_357]

Hi Julio, the material was removed from the outside of the mounting lugs of the caliper(away from the wheel) this moved the caliper out from the wheel so it centered properly on the disc.

John,

Congrats on the successful conversion!   I almost did the same thing, but was adviced to mill away some of the mounting on the fork mounting instead of the caliper itself.

I ended up adding a second 2 piston brembo and carrier to the right side of my front wheel, and now have a setup like a LS bike has (whihc makes sense since almost all the parts came of an LS parts bike. .

[John M]

all the information I have seen makes reference to removing material from the caliper (this means you can always revert back to the original set-up)   Best regards John

[Milo_357]

all the information I have seen makes reference to removing material from the caliper (this means you can always revert back to the original set-up)   Best regards John

Yeah, that makes absolute sense.  Good job!

[Graeme]

Then to ask, is there any difference in braking between the R65 LS (two discs) & the R65?

According to this there isn't:-

BRAKES
The very earliest R65LSs had the same dual ATE calipers as the 1981 R65s.
The dual Brembo front disk brakes are one of the R65LS's best features. .....and I notice little appreciable increase in braking power over the single-disk R65s.

from:-
http://www.nebcom.com/noemi/moto/r65lsfaq.html

I would be very interested in this converstion for my bike if there could be an advantage.

There could also be a possibility (based on need) to extend this to ABS.

[Julio A.]

Nope, other than the brand and number of calipers, they are cross compatible with other dual shock R65's.

[tvrla]

Comparing a single disc to dual is difficult to describe. If the single disc system is working properly it will stop very well. So for mild braking you probably won't notice a difference.

However when you ride and brake hard, tour with a load or passenger on a steep mountain road, you will notice a difference.

Brakes are one of those things I prefer to have the max power and use lightly - but the power is there if/when it's needed.

As for ABS, no way! Too many changes needed; ABS pump (space), computer, and larger alternator just to begin with.