F08 Brembo calipers

[rick79r65]

I’d like to upgrade my twin ATE calipers to Brembo units. I’ve read that the Brembo F08 used on Moto Guzzi are a straight swap. However I’m nervous to order without knowing for certain.
Can anyone tell me if these will fit on my 1981 R65 ?

[georgesgiralt]

Hello,
Maybe Tony will chime in, but mechanically, they are replaceable. But the pistons are not the exact same diameter. BMW used a unique piston size for the ATE and kept it when switching to Brembo.  This make for the premium price Brembo calipers are at the BMW dealer....
That piston difference will change braking. I can't remember in which way, though.

[dogshome]

36 vs 38mm. I doubt this will will make any difference.

What will is the size of the master cylinder, what size pistons your ATEs have now and whether the fork sliders have the same mountings. Pipe fittings may need alteration. Have a look at RealOEM for part numbers and for your bike and say a 1983 R65 with twin Brembos (like mine). The ratio of master cylinder to calipers isn't critical, some working ranges are quoted on various sites.

Note that the twin Brembos are not fantastic. No two finger stoppies are possible! They are very reliable and need little maintenence - probably none between pads unless that is 20 years :-)

[Kelvin]

Moving from 36 to 38mm pistons could push the master cylinder ratio from responsive to wooden. This link, previously put up by wilcom, is very useful in this regard:  http://www.vintagebrake.com/mastercylinder.htm. You may want to change the master cylinder diameter to match the change in caliper piston size.

[Tony Smith]

Increasing the piston size WILL NOT makes your brakes "wooden" in fact far from it.

On the other hand, increasing master cylinder size will also increase the hand effort required which may lead to a "would den" feeling.

For a long time I ran 38mm Brembo F09 calipers with a 12mm master cylinder. I confirm that single finger, back wheel off the deck, stoppies were easy.

It now has a13mmcmaster cylinder as 1/2" cups were more readily available (and cost $0.15 each). Al's other people riding the bike found the brakes scary l.