The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: slickster on July 27, 2011, 01:28:09 PM
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how do I get started installing double disc brakes on the front of my 84 r65?
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You'll need a 15 mm diameter master cylinder, probably three brake lines, depending on what is currently installed in the bike, a line splitter, couple of brackets for the right brake line a caliper and a rotor .
Not too many right side calipers for sale, that may be the part that causes you a bit of a problem to get .
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Along with the right side calipers, the mounting hardware must include some of the proper 'tophat' shaped spacers so the calipers are properly centered on the rotor..
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Hey, I just found one of those elusive dual calipers on Ebay! You might be interested. It's complete with mounting hardware.
;D
http://cgi.ebay.com/ebaymotors/1981-BMW-R65-ATE-Double-Disk-Brake-Calipers-Hoses-_W0QQcmdZViewItemQQ_trkparmsZalgoQ3dLVIQ26ituQ3dUCIQ26otnQ3d4Q26poQ3dLVIQ26psQ3d63Q26clkidQ3d1732020506985220250QQ_trksidZp5197Q2em7QQitemZ280715411038#ht_500wt_975
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Should anyone wish to bid on these ATE calipers, remember the recent posts regarding the NLA pistons. Any pits or damage could offset a bargain price after finding a machine shop to make up some S/S replacements... and paying for them.
Doesn't the '84 R65 have Brembo calipers? The older ATEs may match up with the later model fork legs.
As noted earlier, locating a useable right side disc and associated hardware will be the real challenge.
Monte
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I don't think the ATE and Brembo calipers interchange. And the ATEs were only used up through 81 I believe.
As for the master cylinder, your smaller bore single disc master will work just fine with duals. Actually, it will work much much better.
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Oh, sorry. I didn't notice that your R65 was a '84 model. If it is then it does use a different caliper exclusively made by Brembo. If my sources are right, those calipers are the same ones used by the R80GS/ST and Earlier model R100 GS.
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The R80ST and R65 calipers have different part numbers in the fiche. It doesn't look like they interchange with anything else.
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Consider trying to improve the single stopper you have - it will be cheaper and you will still have the advantage of less unsprung weight.
I am the mad Limey who converted his from dual to single.........
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I don't think the ATE and Brembo calipers interchange.
I have a set of ATE calipers in the attic, so tried them on the LS. What do you know? They mount right up!
So I guess the sliders are all the same and the ATEs and Brembos do interchange.
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Consider trying to improve the single stopper you have - it will be cheaper and you will still have the advantage of less unsprung weight.
I am the mad Limey who converted his from dual to single.........
Not mad in my book.
A purely technical argument and these are very marginal effects maybe a few percent but from a performance point of view the wheel is the worst possible place to add weight on a bike because of a triple negative effect.
You add to the overall weight of the bike - it will accelerate and brake slower. (by brake slower I mean you lose a little of what you gained by adding the 2nd disk)
You add to the unsprung weight - this cannot improve ride and road holding.
You add to the rotational inertia - the wheel is harder to speed up and slow down so you accelerate and brake slower. (this is an additive effect to the overall weight increase but again by brake slower I mean you lose a little of what you gained by adding the 2nd disk)
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Consider trying to improve the single stopper you have - it will be cheaper and you will still have the advantage of less unsprung weight.
I am the mad Limey who converted his from dual to single.........
Long time no see Steve.....
My 79 has ATE twins my brothers 81 has Brembo twins they do not inter change
Lou
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Along with the right side calipers, the mounting hardware must include some of the proper 'tophat' shaped spacers so the calipers are properly centered on the rotor..
"tophat" shaped spacers? Are those thing things that the mounting screws go through?
Also, I've been thinking of doing this for a while, I go up and down some. Pretty steep mountains at times. Are you guys saying I am wasting my time going to a dual front brake? :(
Dell
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No, we are not saying it is a waste of time. However, we are saying you could improve the single brake first and it might be enough for your needs.
If you are careful it will not be money wasted as you will still require that side of the brake any way, even if you eventually go for a dual disk set-up.
Just give it some thought.
Dual brakes will give you better braking - but there are other things it will give you as well - more unsprung weight and an emptier pockets.
I have to add, I went from dual to single and yes I lost outright power but gained 'feel'.
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I double disc'd my Brembo equipped 1983 R65. The ultimate stopping power didn't increase too much - front wheel is easily lockable with twin or single discs - but I find I am able to brake more closely to lockup consistently with twin discs. I haven't noticed adverse unsprung weight issues with additional disc and caliper.
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Well, it won't cost me anything to add the extra brake, except brake fluid. I have all the parts from my parts bike. I'm going to do it next month and let you all know what happens.
Dell
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Well, if you have all the parts, then cost is not an issue. And probably for day to day riding on the slab you will probably not be too concerned with unsprung weight either.
But make sure the parts you fit are in good order...