The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Mucci on May 08, 2020, 01:28:43 AM
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I’m in the midst of upgrading the braking on my ‘83 R65 and thought I would share my experiences as I go.
First up is replacing the warped rotor. As anyone who’s called the dealer likely found out the OEM replacements only exist in the country in single digits and they’re something to the tune of $300+. Speigler used to offer a service where they replace just the disc on your existing OEM rotor hub. According to them they no longer can get the discs and have discontinued this service.
You can however get the disc from Braking. I got one on eBay for $99 shipped. Here’s how to install it:
PN: BW01FI
Here’s what you get.
(https://i.imgur.com/AeFCOp8.jpg)
Laid over stock rotor.
(https://i.imgur.com/ZJ7mamt.jpg)
Use a punch to mark the center of the rivets.
(https://i.imgur.com/vcHv4o3.jpg)
Cover the hub hole to avoid shavings getting in there. I used a rubber stopper.
Use a drill bit about the same size as the rivet to take most of the meat off. Stop before you get into the rotor to avoid going too far and eating into the hub. (Left)
Use a grinder to take off the rest. (Right)
(https://i.imgur.com/xkBUzft.jpg)
Use a punch to knock out the rivet (right).
(https://i.imgur.com/bGZeFUV.jpg)
Pull the rotor off and clean the rotor hub of all shaving and debris.
(https://I.imgur.com/sZxMbwR.jpg)
Clean the new rotor with brake clean.
The kit comes with two length bolts. Use the longer ones. Install the hardware in this order: Bolt, countersink spacer, wavy washer, rotor, washer, nut.
FYI the bolt and nut are pretty low grade and I had one pair bind on me that I then had to chase with a tap and die. I would have swapped them out for stainless if I had them in stock. Snug them up by hand with a ratchet to avoid them cross threading.
The Braking directions say to use OEM torque specs but of course our bikes don’t list this. I went with 10 ftlbs because that’s what my KTM rotor calls for.
Here it is all buttoned up:
(https://i.imgur.com/ubkvvkD.jpg)
Next I’ll be tackling making a 4-piston Brembo caliper from the R/K1100 work on the bike.
I got some EBC organic pads (FA246) for $20 shipped and the caliper for $30 shipped, both on eBay. Just waiting for the parts to come in.
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I wish I would have known about this when I replaced mine :'(
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Motobins is out of stock on both
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Hummmm...
The BMW Classic Shop list them as available today at a whooping 306 € a pièce ...
So if you want to go the OEM route, you can... ;D
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Is the replacement rotor stainless steel ?
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Is the replacement rotor stainless steel ?
Yes, Stainless.
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I made some very interesting discoveries this weekend in my quest for upgrading the stock caliper.
Others have used the 4-piston Brembo caliper on bigger airheads saying that the mounting holes are identical; caveat being that the caliper bosses need a little machining to work.
So I thought I'd pick one up and see if the same is true for the R65. In summary, I was able to make it work without machining the mounts, and for only $50 (caliper and new pads).
Here's the process:
https://advrider.com/f/threads/the-50-4-piston-brembo-brake-upgrade.1444863/
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Great write-up !!!
This is the one area of the R65 that really needs improvement .
Something I'm going to look into once the temps here go down in October .
Be looking forward to your experience with this modification .
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Great write-up !!!
This is the one area of the R65 that really needs improvement .
Something I'm going to look into once the temps here go down in October .
Be looking forward to your experience with this modification .
I've only had 2 hours on it so far but it's so much better. The 15mm master is spot on in my opinion.
It's not modern sport bike level of single finger stopping power but I'd finally put the bike in the "good brakes" category. I could always add a 2nd to the other side but that gets more complicated. Plus it's damn good as is.
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This is great info on the rotor replacement. I'd already had the spiegler mod, and was wondering what to do next time the rotor wore out. I can probably have it machined next time I do the brakes, but this looks like a very simple replacement.
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This is great info on the rotor replacement. I'd already had the spiegler mod, and was wondering what to do next time the rotor wore out. I can probably have it machined next time I do the brakes, but this looks like a very simple replacement.
I wouldn’t waste your money machining it. I tried that and even though it was still at the min. thickness limit it warped within a day.
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In my youth, I studied mechanical engineering.
Rectifying a thin piece of steel is a difficult job. You have to take a very thin pass on one side, preventing the piece to heat (plenty of lubrication), let it cool then turn it on the other side and do the same on the other side. Repeat the whole sequence until you reach either the proper dimension or have removed the problem. And it is not warranted to work well ....
I wonder if, given the price of workmanship these days, anyone take the burden to do it properly. Hence, the part ends warped or worse.... This is why nobody sharpen the blades on wood working planing machine but replace them. The cost for new blades is less than an our shop labor....
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I can tell you BMW does no such thing. I brought it into them and they said they told me “you don’t resurface motorcycle rotors. You replace them.”
You know, for $350 ea. and that’s not including labor ;D
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I wouldn’t waste your money machining it. I tried that and even though it was still at the min. thickness limit it warped within a day.
The stock rotor or the spiegler replacement?
At $100 for a new rotor, I agree it's probably easier to just replace it.
In a few thousand miles I'm going to do the brakes on my '17 Tacoma, I've already decided I'm not going to mess with the rotor, and I'll just replace it when I do the pads a second time.
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You can machine disc on a car/truck. They’re vented and way beefier. Shops do it all the time.
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Mucci, do you have the dimensions for the braking rotor you got? While I've got my caliper off I'm going to replace the rotor too, and I'm either going to replace just the rotor with a braking one, or get an EBC.
The EBC I'm looking at is https://ebcbrakesdirect.com/motorcycle/bmw/r80-r-80-rt-single-rotor/1984-1990/31695
Edit: Did some looking, looks like the rotor for my mono shock is this one. The twin shock rotor is 260mm, mine is 285mm, which checks out with my paperwork from Spiegler.
http://www.braking.com/catalogue/dettaglio_prodotto.php?codice_articolo=BW02FI
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Mucci, do you have the dimensions for the braking rotor you got? While I've got my caliper off I'm going to replace the rotor too, and I'm either going to replace just the rotor with a braking one, or get an EBC.
The EBC I'm looking at is https://ebcbrakesdirect.com/motorcycle/bmw/r80-r-80-rt-single-rotor/1984-1990/31695
Edit: Did some looking, looks like the rotor for my mono shock is this one. The twin shock rotor is 260mm, mine is 285mm, which checks out with my paperwork from Spiegler.
http://www.braking.com/catalogue/dettaglio_prodotto.php?codice_articolo=BW02FI
Do you still need dimensions from the 260mm rotor? Good to know they make a 285mm too!
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I outline another plan (that I haven't implemented), that of moving from the stock 38mm caliper with single disk to a 48mm, here: https://www.bmwr65.org/YaBB2.612/cgi-bin/yabb2/YaBB.pl?num=1511573205/8#8
When I thought it through a while ago it was cheaper than the dual disk conversion.
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Great write-up, but you went to a lot more trouble than was necessary to remove the rivets from the old disc. Given that you are not goign to reuse the old disc I just deployed the angle grinder and removed the heads of the rivets (ad some of the disc), a pin punch removed them whilst still warm.
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Hi Mucci, I like the rotors and the write up. The only thing I would change is the bracing via the mudguard/fender.
Mine was quite sensitive to road imperfections until I fitted a dual loop steel brace. i was pretty sceptical that it would do anything, but it did.
So where you have spacers to fit the standard pressed brace, I can only imagine it give a little more flex.
I find the dual standard discs quite good, now rebuilt. My friend has a Harley Sportster with single disc (+100 lb of iron engine) and describes it as puny. I can imagine a single disc on the R65 is something in between.
He never goes much above 65MPH, so for him to complain about the brakes means it really isn't great!