The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Crossrodes on September 12, 2007, 06:27:57 PM
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I just did an inspection and maintenance on the brakes of the new to me R65. The caliper pistons are in marginal shape. Does anyone have a good source of pistons in North America or, better still, is there a replacement caliper that I could use instead of the ATE?
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I believe that the pistons are not available from BMW anymore, so your next choice would be a used caliper off of a newer R65 that uses ATE calipers, or moderator JusitinB, made up a set of stainless for his LS. I think another moderator here Rob Valdez 79 R65, got pistons from Motobins in the U K, and price including shipping was quite reasonable.
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I just did an inspection and maintenance on the brakes of the new to me R65. The caliper pistons are in marginal shape. Does anyone have a good source of pistons in North America or, better still, is there a replacement caliper that I could use instead of the ATE?
Mike, BMW began switching to Brembo in '81, and I think the changeover on your '79 wouldn't be a big deal: the ATEs were basically Brembo copies anyway. Or, as Bob said, Justin may have another set of pistons laying around
But, I'm betting Rob already has info on this and could definitely steer you in the right direction, being the Master on the '79s.
I would hope there would be no master cylinder issues.
Good luck [smiley=thumbsup.gif]
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Mike, BMW began switching to Brembo in '81, and I think the changeover on your '79 wouldn't be a big deal: the ATEs were basically Brembo copies anyway. Or, as Bob said, Justin may have another set of pistons laying around
Sorry Steve, anything but the fact, the two are chalk and cheese in design as well as performance. The ATE's are swinging single piston calipers of German design, the Brembo are twin piston fixed of Italian design (those Italians know how to make stoppers!!).
To change to Brembo would require two fork legs as well as a M/C change, expensive. Like was said before, Motobins have the complete ATE kit with piston, just make sure you know the correct size, they came in 38mm and 40mm.
Bill.................;-)
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Well see, that just goes to show ya how little I know about ATEs, and how sometimes it's a bad idea to listen to strangers! ;)
Thanks for correcting me, especially before any real damage was done!
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I know about the two sizes. To check mine I measured the piston diameter...it was just over 35 mm??? What do you measure to determine size?
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Mike, BMW began switching to Brembo in '81, and I think the changeover on your '79 wouldn't be a big deal: the ATEs were basically Brembo copies anyway. Or, as Bob said, Justin may have another set of pistons laying around
Sorry Steve, anything but the fact, the two are chalk and cheese in design as well as performance. The ATE's are swinging single piston calipers of German design, the Brembo are twin piston fixed of Italian design (those Italians know how to make stoppers!!).
To change to Brembo would require two fork legs as well as a M/C change, expensive. Like was said before, Motobins have the complete ATE kit with piston, just make sure you know the correct size, they came in 38mm and 40mm.
Bill.................;-)
Bill, the ATEs on my '81 R65 are twin piston fixed calipers, and work well. Of course, my '81 has two of them. ;D From a distance these ATEs are difficult to tell from Brembos. They are nothing like the ATEs you described, the swinging single piston calipers.
Dunno what BMW used in '79, of course, but not all ATEs are the same.
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All,
I am using post 81 brembo calipers with a 1979 master cyclinder specified to be used for the ATE calipers you are having trouble with.
The master cylinder is of a different bore that that supplied eith the Brembo's, so the braking experience is different. If anything the brakes work too well, with little progression. However they are strong and work okay. Eventually I will swap the master cyclinder to match the calipers, when I find a serviceable one cheap.
I did this because, at the time, it was cheaper to buy second hand brembos that it was to buy an overhaul kit/s for the ATE's.
No modifications were necessary. I also changed the lines at the time for stainless steel BFGoodrich items, but I suspect this was the step too far - i.e. with regard to progressive operation.
Steve H
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Steve were the '81 Brembos designed for a BMW and if so which model? Did you change rotors also? I know from experience that stainless brake lines will change the feel of your brakes, so that may be the reason for the change in braking experience.
Mike
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I have Brembos on both my R80 and R65. Great brakes and a big improvement over the ATEs. I can stop without dragging my feet. Seriously though, you might try RePsycle for your parts. Mark has the biggest inventory of airhead parts I have ever heard of. Anytime I need anything it is in stock, usually both used and new. Been dealing with him for about 15 years.....Dew.
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Mike, BMW began switching to Brembo in '81, and I think the changeover on your '79 wouldn't be a big deal: the ATEs were basically Brembo copies anyway. Or, as Bob said, Justin may have another set of pistons laying around
Sorry Steve, anything but the fact, the two are chalk and cheese in design as well as performance. The ATE's are swinging single piston calipers of German design, the Brembo are twin piston fixed of Italian design (those Italians know how to make stoppers!!).
To change to Brembo would require two fork legs as well as a M/C change, expensive. Like was said before, Motobins have the complete ATE kit with piston, just make sure you know the correct size, they came in 38mm and 40mm.
Bill.................;-)
Bill - I think your thinking of the pre 1979 ATE that is on the everything but the R65. The ATE on the R65 are dual piston just like the Brembo. Also, I thought the part number for the forks was the same so I think a Brembo Caliper will bolt on a leg that just held the ATE. My 1980 parts book list only one fork leg but both calipers. Surely the '79 is the same?
BTW - I have the dual ATE's with the floating EBC rotors and I am using the Brembo pads in the ATE caliper. You have to cut 'em a bit to get them to fit but it works. More compond choices with the BREMBO. (I have Galifer Kevlar.) I'll post a pic when I change them out here in a bit.
TTFN,
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SemperG, did you have to cut out at the top of the pad backing steel to allow the anti-rattle spring to fit properly ? I installed the EBC graphite pads , and had to remove about 3/16 ths inches off of the steel back plate to get it work .
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We you go to realoem.com it show only one fork leg for all early R65.
Don
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SemperG, did you have to cut out at the top of the pad backing steel to allow the anti-rattle spring to fit properly ? I installed the EBC graphite pads , and had to remove about 3/16 ths inches off of the steel back plate to get it work .
Hi Bob,
Yesh! I cut notch the width of the anti-rattle spring down to a depth even with the middle of the two instalation pin holes. The pad hangs a hair low on my EBC rotors which causes a bit of a vibration until i take a touch off the bottom of the pad. On the solid BMW rotors this *should* not be a problem (?)
TTFN,
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Semper G....the ATE's on my '79 R65 are a single piston caliper plus there are twin front rotors with a rear drum. This bike was originally purchased and used in Germany and later shipped to Canada. Is it possible that the Euro Spec model had different brakes than the US spec model?
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The Brembos fitted to my 1979 bike in place of the ATE dual piston Calipers, are just the Brembos fitted to the later R65s. This has nothing whatsoever to do with the horrible swinging caliper single piston jobs. The fork legs are the same for pre and post 1981 R65s as far as brake fitment is concerned.
However the master cyclinder is different, which accounts for the change in feel.
No R65 was fitted with those ATE single piston swinging calipers as standard. If anyone has an R65 fitted with those brakes it is because the front end has been replaced for some reason with an earlier set of forks.
One of the reasons I chose the R65 for my Cafe Racer project was so I could avoid having to look at those horrible swinging piston calipers and fork legs. I would have preferred an earlier front end with a drum brake. I also wanted a decent set of yokes(triple trees?) for the forks - R65 again.
The ATE's fitted to 1979 R65s are similar to the brembos in so far that they are a twin piston caliper - one piston either side of the caliper. There are no moving parts except the pistons and no ridiculous setting up routines
Cheers
Steve H
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Steve please describe how I can tell if I have swinging calipers. The ATE calipers look like any other design to me. :-/
Modified to say that I lied. These calipers are a dual piston caliper which I believe were standard on early production bikes. I must have had a brain fart. ::)
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Motobins still has the pistons, around $96 USD.
http://tinyurl.com/22cq7d
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.motobins.com%2Flibrary%2F23075.jpg&hash=d1142906b50c34797c326a41f04bd5d2f0be2fa6)
You might drop Justin a line to see if he could be competitive with that. Shipping from England was not even $6.50 USD 18 months ago.
Yes, you have twin piston calipers. No, they do not float.
I will never understand how the ATE is a copy of the Brembo when the ATE came first.
And here are some pictures from when I rebuilt mine:
http://www.pbase.com/tomfarr/r65_brakes
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Rob, who is Justin and where will I contact him?
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Justin is our host, the reigning Administrator/King here at R65.org, as well as a helluva painter, machinist and all-around Beemerologist Deluxe: nice guy too! [smiley=thumbsup.gif]
Reach him via PM or email from the Members list, or anywhere else "Justin B" appears.
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After turning out a pair of these for a Brembo I can vouch that they are pretty labor intensive so I don't think I could be very competitive. Plus, I don't have any ATE pistons to copy so I'll have to pass...
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Semper G....the ATE's on my '79 R65 are a single piston caliper plus there are twin front rotors with a rear drum. This bike was originally purchased and used in Germany and later shipped to Canada. Is it possible that the Euro Spec model had different brakes than the US spec model?
Could you post a picture please? Inquiring minds would like to see. I wonder if somebody put a 1978 or earlier front end on your bike? :-?
Thanks,
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Semper G I corrected that quote with this:
"Steve please describe how I can tell if I have swinging calipers. The ATE calipers look like any other design to me.
Modified to say that I lied. These calipers are a dual piston caliper which I believe were standard on early production bikes. I must have had a brain fart."
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BTW, I found rebuilding my brake system one of the most rewarding and enjoyable tasks yet.
When I pulled out the first piston, I knew my efforts were NOT in vain!