Topic: Road racing calipers and pad compounds.

[gschuld]

I’d like to get some info on calipers and pads being used for road racing

Factory calipers
AP Racing(Lockheed)
Grimeca
Brembo 05/08/p108

The cp211 pads are gone, replaced with the CP1 (carbon based)
Yossef favors the Brembo SC pads

So who is using what?

George

[Tintop]

You can likely take Gimeca off your list.  Rebuild kits are very hard to find, and no they do not use the Brembo kit!  Been there.

[754]

Dang, I bought up about a 6 pack of Grimecas.. some have good pads.

[scottly]

Opposed piston calipers don't play well with the narrow fork spacing on our bikes, due to interference with the spokes, and have no hydraulic advantage over single sided calipers with the same piston surface area. The best bang-for-the-buck caliper I've found is the 32mm two piston version used on the mid 80's V65. With F2/3 fork legs and thinned 550 rotors, it's a bolt-on upgrade with the right factory parts. In my case, I adapted a single Ducati 320mm rotor and have better braking than with two stock K7 calipers, using EBC pads with an FF rating, IIRC. Granted, my interest is a panic stop situation, not a more hard core continuous braking torture test like found in road racing.

[gschuld]

Scotty,

Yes your points are well taken.  I wouldn’t want others reading this thread to think otherwise.

I am well aware though of the figment issues of opposed calipers on our bikes, especially at our OEM 182mm fork spacing.  It can be and has been done, but it’s a PITA to make work and a super tight fit. Some race with wider fork spacing as well.  That said, I do like your solution.👍

Racing rules limits racers in CB750 qualifying classes (in the US anyway) to either vintage two piston opposed calipers(Brembo f05/f08/P108, Grimeca, AP Racing(Lockheed) 2696 etc) or single piston one sided calipers(generally for us vintage factory calipers from cb750s, gl1000/1100s, etc). Of these choices the AP Racing 2696 calipers have probably the strongest following performance wise.

12” max non floating rotors are a must too(US anyway)

Finding pads in favorable racing compounds in the above caliper choices can be from limited to non existent.  It’s not unusual to alter modern bike pads to work in some of these calipers.

For example, there is not a single proper race compound pad set available for our cr750s with factory calipers.  There are street compounds pads that have shown to be minimally acceptable on the track, but that’s it.  I am not even aware of any custom small batch race pads available regardless of price.

I would be pleased to be wrong...

Good info on Grimeca calipers rebuild parts issue.

George

[Tintop]

Just a quick follow-up on the Gimeca 35mm rebuild situation.  They look like they can use the Brembo f05 kit but the piston seal is wrong (too thin), & the dust seal is just an OK fit.  You can buy replacement pistons.  Midwest Calipers outside Toronto made up some kits for me a couple of years ago.

[gschuld]

Just a quick follow-up on the Gimeca 35mm rebuild situation.  They look like they can use the Brembo f05 kit but the piston seal is wrong (too thin), & the dust seal is just an OK fit.  You can buy replacement pistons.  Midwest Calipers outside Toronto made up some kits for me a couple of years ago.

Good to know, thanks

George

[simon#42]

you dont need to have a batch of pads made , over here you dont anyway . you can have your original backing plates rebonded with any friction material you like .

[turboguzzi]

im kind of sorted on pads but interested for other projects... who does it and what racing compounds are available?

[gschuld]

im kind of sorted on pads but interested for other projects... who does it and what racing compounds are available?

Yes, what Yossef said.

Dick Hunt Racing in the UK?

George

[Tintop]

THere's a company near Toronto that re-lines brake shoes for racing.  Don't see why they couldn't do disk pads.

[scottly]

Now that you guys mention it, my neighbor has a product which uses a friction material similar to brake pads, bonded with some sort of adhesive, which he does in-house. I'll ask him where he gets it, and if his supplier has different compounds.
George, are there still compounds available that are suitable for cast iron?
 

[754]

Those rotors should be lighter.
 I SHOULD KNOW BETTER but I ended up buying yet another Grimeca big caliper yesterday. Cuz it was cheap 60 bux.. had good thick pads, good lettering., they interchange on mount pattern with AP, some PM , as far as I know. They were used lots on dragbikes and flattrackers.

[simon#42]

there are two people i have used for bike pads and shoes i, i will dig there phone numbers out . one was in wales and one was in yorkshire   

[Tintop]

This is the company outside Toronto (Woodbridge, ON) that does brake shoes & pad relining - http://phoenixfriction.ca/

[simon#42]

brake reline services
unit 2 west point ind estate
penarth road cardiff
cf11 8jq

these are a good firm .    have also used brake reline.co.uk but not sure if they are still trading

[Rocketman]

Vintage Brake may be able to help you out. 

https://www.vintagebrake.com/