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Author Topic: F08 Brembo calipers  (Read 200 times)

Offline rick79r65

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F08 Brembo calipers
« on: May 14, 2023, 08:03:07 AM »
Iíd like to upgrade my twin ATE calipers to Brembo units. Iíve read that the Brembo F08 used on Moto Guzzi are a straight swap. However Iím nervous to order without knowing for certain.
Can anyone tell me if these will fit on my 1981 R65 ?
« Last Edit: May 14, 2023, 10:07:24 AM by rick79r65 »

Offline georgesgiralt

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Re: F08 Brembo calipers
« Reply #1 on: May 15, 2023, 01:21:31 AM »
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.

Offline dogshome

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Re: F08 Brembo calipers
« Reply #2 on: May 15, 2023, 04:22:59 PM »
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 :-)
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Offline Kelvin

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Re: F08 Brembo calipers
« Reply #3 on: May 15, 2023, 05:16:33 PM »
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: You may want to change the master cylinder diameter to match the change in caliper piston size.
1983 R65LS 1985 to 1988
1983 R65LS 1996 to present.
1984 R65LS 2019 to present.

Offline Tony Smith

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Re: F08 Brembo calipers
« Reply #4 on: June 26, 2023, 11:45:04 PM »
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.
1978 R100RS| 1981 R100RS (JPS) | 1984 R65 | 1992 KLE500 | 2002 R1150GSA |