The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: its_only_me on February 18, 2007, 04:26:08 PM
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One of the problems of not having a garage or workshop and therefore having to work out doors is not having a decent workbench to strip and clean parts. this being the case I removed my r/h (as when sat on bike) caliper, but never noticed the two small "top hat" spacers that fell off when I started to clean the caliper, so I am not entirely sure where they go back.
I did then look at the l/h caliper, but that does not have the same two spacers.
So do they go between the fork leg and the caliper on the r/h side?
I will take a digi pic tomorrow so you can see what I am talking about, if the above is not to clear.
I wonder why these spacers are only used one side.
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Why don't you go to REALOEM.com and put the last 7 characters of your bikes serial number in the appropiate place, and then go to the brakes section, it looks like the bushing goes in the forward mounting hole of the caliper. I would guess that they are installed on the outboard side of the caliper under the bolt head.
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Put the wheel back on properly. Slide the caliper onto the disk in the normal position. It will be easy to see where the spacers go, by the spacings between fork leg and caliper.
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I didn't realize there were any spacers. :-? My '82 LS had the calipers removed and disassembled when I got it - guess that's a couple more bits that must be missing as I don't remember anything like that in the box... :( I already had to lathe out a set of caliper pistons so maybe you could measure them and post sketch/dimensions and I could build some if I need them. What does it look like they are made from?
I do note in the HTK it shows something like a shouldered spacer/bushing in the mounting holes where the caliper is bolted to the slider, but the picture looks like the ATE and my LS has Brembo calipers. Maybe this is something peculiar to the ATE calipers?
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My single (left side) ATE caliper had no such bushings.
As I understand it, the ATE's were copies of the Brembos, indicating that they could look alike in a microfiche drawing.
Kevin, can you confirm which calipers you have?
It is also possible that only the right hand caliper needed the bushings...?
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Ok thanks for the replies, now from the top...
1. As I said in the header I have Brembo's
2. I looked at the realoem site before my original post and it is not clear. I also looked in the Clymer and they are not shown there at all.
3. I did align the disk, and it seemed right to put them on the inside between slider and caliper, as this seems to centre the disk rotor, but wanted confirmation on this, as the L/H doesn't have them?
4. I will take them off again and take pictures/measurements
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You have it right. I mean it can't go on any other way if the caliper is sitting on the disk, then if there is a gap between the caliper and the fork leg and you have spacers that match that gap, you are aced. Because otherwise you would be forcing something as soon as you tried to tighten the bolts.
Oops, I just re-read your original post. When you say 'top hat' you are giving a literal description? Will the top of the 'hat' fit in bolt hole that holds the caliper to the fork leg? From the inside? And basically still solve any gap (this would be the 'brim') as I mentioned in the first paragraph?
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This is a pic from the HTK, and remember that the newer ATE calipers on the R65 look very similar to the Brembo items. The spacer/bushing I referred to in my previous post is number 12. I mentioned ATE because the anti-rattle spring (item 9) shown in this pic is not like the Brembo spring/retainer which looks like the spring in repair kit 17-RS.
From this illustration it looks like they go into the mounting holes and the HTK lists 5 different part numbers for different sizes of #12. If you insert a mounting bolt through one of these holes is there a lot of slop?
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Well, after seeing Justin's diagram, I think I am wrong with my comment about putting them on the inside. It looks like they go from the outside, and the calipers will be tight against the fork leg. But I am a little confused if as you said the caliper seemed centred on the disk the other way around.
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But I am a little confused if as you said the caliper seemed centred on the disk the other way around.
As am I?
Number 12 is the item, now I may be stupid (the jury's still out on that one) but if it goes as shown above, then all it is doing is making the bolt shorter, as the caliper would be tight to the fork slider.
Where as if it goes the other side of the caliper, it moves the caliper away slightly from the slider by the width of the spacer, and so gives you a way of centering the rotor in the caliper, would this not be the reason for having them available in different sizes?
The problem is, I really don't know where they were originaly, as they were caked in crud, so when I soaked the caliper in cleaner they came loose, but not realising they were there, when I was cleaning the caliper half they fell out, before I saw them :(
Oh well it can wait untill the weekend now, as it is dark when I get in from work most days, maybe someone who has Brembo calipers on there 65LS will have a look and put us all right. ;)
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Well I went out and took a look at my Brembo caliper on my R65 (not an LS) and it is flush against the fork bracket. (This is the left side, so this may not be appropriate at all.) I did NOT take anything apart and if there is a spacer there then not much of it is showing. I did see a small ridge that could be the spacer between the bolt and the caliper on the outside, not the inside. They also look centered on the rotor. So that would validate the picture from the fiche, even though what you said makes a lot of sense.
Maybe there's more to this than I can see without taking it apart. (https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.smileyhut.com%2Fmisc_expressions%2Fg.gif&hash=51c2b337699a891d03fd7c3c21d990cd4234c065)
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Aïda, the HTK shows five different part numbers for this critter and I am assuming something is different in the sizing, or something. Do you have a grizzled ol' airhead wrench left that might know why there are different ones? Here is a snapshot with the different part numbers:
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When I put on the EBC rotors (and at the same time changed out the wheel bearings) I had to go to a larger shim on the RH caliper. LH side was fine. This got the right caliper "centered" on the rotor and helps keep the pads from dragging on the rotor when "relaxed". Did it all by eyeball.
TTFN,
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Wish I had dual front brakes. :(
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Justin,
I agree with you on the different part number choices. Wish I knew what it meant. Looking at the Max BMW fiche for same, the prices are all over the board for what seems to be just a bushing.. like $3-$7.
I can't get to that side of our R65 easily in its winter storage location, but I was wondering if the right side ATE caliper being an add-on at the time, could it have been designed originally for a different manufacturer (before BMW came along and wanted to source a caliper). And the mounting holes on this right caliper are maybe larger than what was on the left, but BMW still wanted to use same size bolts (M10 x 30) . So they supplied a 'top hat' bushing which 'sized' the hold down to use M10's. Now, I may well be full of it.
Question for 'it's only me' - are the bolt holes on the right caliper without the 'top hat' a larger diameter than the left?
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Chris, that's what I was wondering about hence my question to him about putting a bolt through the mounting hole to see how much slop there was. But, that doesn't explain to me the different sizes. I suppose that the parts diagram could be wrong about the orientation and they are actually supposed to be inserted from behind. That would make sense for the assortment, maybe a different thickness to the "brim" to help center the caliper? Hopefully Melena can find somebody around their shop that might know...
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Ok then, managed to catch a bit of daylight today when I got in from work, so I will try to answer those questions above...
1. the mounting bolts are the same for both left and right side.
2. the mounting holes in the caliper are bigger on the r/h side (but the top hat bush is not the same width as the caliper, so I feel the caliper has been made with a bigger hole on purpose?)
3. I think the diagram shown above is wrong, and the spacer goes in between the slider and caliper. (I will explain this below)
3a. I think the different sizes are due to the thickness of the rim of the spacer used to centralise the caliper to the rotor (I will explain this below)
Right then, if you look at the image below, you will see the spacer (A) mounted on the outside as shown in the diagram above, but you will also see that with the brake shoes in place there is a gap between caliper and slider (B) and with the bolts done up hand tight I am unable to turn the front wheel.
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi5.pbase.com%2Fo6%2F05%2F429105%2F1%2F74627942.DGtSqdiL.R65LS002m.jpg&hash=257e4378cc78731aecdaffa3f0cce77d41839f0b)
If I then move the spacers to the inside between the caliper and slider, again with the bolts hand tight, I can then run the wheel through with no rubbing against the brakes. This is why I feel the spacers go on the inside, and also why they are available in different thicknesses.
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi5.pbase.com%2Fo6%2F05%2F429105%2F1%2F74628036.4y89HRsN.R65LS006m.jpg&hash=1ebc8386b814dab8da5405b16a81e8019082989b)
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May I suggest that you post this on Boxerworks.com, there is a larger group of knowledge there, and I believe that the Brembo calipers were used on a variety of BMW bikes, airheads and early K- series as well.
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Kevin, I think that you have nailed it and it's the only reason I can think of to have 5 different bushings and parts diagrams have been wrong before. :o I went outside and looked at my wife's '84 and without taking it apart I can't see any bushings at all, but her bike is a single disc on the left and you indicated this bushing appears to be used on the right caliper. The brakes on the '82 LS were disassembled when I got it so who knows on that one... :P
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Well it looks as though we can draw a line under this one, as my findings have been confirmed by a poster at Boxerworks.com So thanks for all the help offered.
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Hi Kevin,
That is what I did with mine. I didn't know there was a problem with the diagram. Somehow I just figured it out.
TTFN,
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I've had mine apart several times, but honestly cannot remember the exact orientation - will check in
the morning and report back (mine is the '82 LS)...
-Mike
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OK, I had to go to the store to get batteries for my digital camera, and now my login for my photo site is
messed up....
BUT, indeed, on my 82 LS there are spacers on the right hand side (Brembo calipers) and the wider
part goes between the caliper and the mounting boss on the fork slider. The left hand caliper appears
that it may / may not have a bushing in there, but if it does, it is paper thin and it appear that the back of the
caliper is mounted flush against the mounting boss on the left slider. With these setup in this manner,
the rotor are perfectly centered between the pads. So, I guess that there are differences between
left and right side brembo calipers' mounting hardware to ensure that things are properly aligned.
The probably needed the different thickness bushings to accomodate the LS wheels. snowflakes wheels, and
the different single and dual rotor setups, do you think ?
If you still need to see photos, I'll try to sign up for a new photo website account if I can't get this one working....
(grumble grumble)