1975 BMW R90/6 - Rocinante

That’s awesome. Love big brakes on vintage wheels.
I brought the mufflers home yesterday and did some shining today. I couldn't resist bolting the left one on just to get a look at it. They don't shine up too bad and I think with more time spent I can get them a little better. I'm not sure what they'll sound like, the outlet is fairly small, I guess time will tell. They aren't perfect and are heavy, but they're very solid and I think will give the look I'm going for.

I got in the spring compressor I ordered for the rear shocks. I pulled the left shock off a few days ago and it was obvious very quickly that there was no way I was going to get the things cleaned up and presentable w/o taking them apart. I watched some YouTube vids and hoped to do a rebuild and new oil while I had them apart but these don't seem to come apart so a clean-up is all they'll get. There's no sign of the seals leaking things should be fine. The mount bushings aren't fantastic but not terrible, I'll replace them in the future.




After, cleaned and the spring repainted:



And back on:


I was about to grab the torque wrench but remembered that the mounts for the Wixom panniers attach to the top shock mount bolts so progress slowed until the last coat of paint on the mounts was sprayed.

The stainless fastener set is nice. They charge a bunch more for having them polished so I didn't go that direction. I might throw some into the tumbler I use to clean reloading brass but if there doesn't seem to be much difference I probably won't bother. I'll throw some in tomorrow and let them run for a couple days.



Cold and snow here, much like a big part of the country it seems. I feel a bit stupid, after all the years I spent in severe cold country I managed to lightly frostbite the ends of three toes. We've been going south for the winter long enough that my proper cold weather gear is all but gone except for decent coats. There's no excuse, though, I know better. Over and over I got my shoes, socks and feet wet taking the dogs out then I went out to the shop to work, didn't take proper care of myself; I got what I deserved. I now have decent socks and good boots and will take better care. Duh.

I got the right side shock off and apart today. If anything, it's worse than the left one was but, like the left one, it functions well but is covered in fifty years worth of crud.


Hopefully I'll get it cleaned up and back together tomorrow. I got a coat of paint on the spring so it'll be all ready to reassemble once the other parts are ready. I may not be fast but if I keep moving it's GOT to be ready by Spring, right?
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The right shock has been cleaned, reassembled, and reinstalled.


I've started replacing all the nuts and bolts with the SS pieces as I work my way around the thing. The stainless set is pretty nice and there are lots of pieces. The explanation in the write up for the set is since it's a set for both /6 and /7 there may be extra parts that won't used and I can see that. For instance there's a bag of parts each for both rear drum brake and rear disc brake bikes. At times the extra pieces and differing length bolts is confusing, though. After messing around with it I've finally settled on putting like-length bolts in places where they can be seen and put the longer-than-they-ought-to-be bolts in places where they can't be seen and won't cause trouble. On down the road I may go back w/ the Dremel and shorten them. They aren't OEM and for sure don't look OEM but I don't see it as an issue. The Vintage BMW Motorcycle Owner's group classifies old BMWs as Antique (1923-1945), Vintage (1948-1969), and Classic (1970-25 years ago). If I was working on a machine that is Antique or Vintage (or if this was a R90S) I'd be more particular about trying to be more original with things but there were more than 21,000 of the things built so I don't feel bad about making it my own. If sometime in the future an owner wants to do a real restoration, more power to 'em.

The project has advanced to the front end and time to refresh the forks and put in the Progressive Suspension fork springs that came in the box of extra stuff. I have hoped that even though it hasn't been ridden in over thirty years I'd be able to just take the fork tubes off, clean things up and put in new fork oil. The day we brought it home both Levi and I checked the fork action and thought they seemed to be ok. Today I loosened up the first rubber gaiter and found if half full of thick, sticky honey. I'm pretty sure that's old fork oil that's been sitting in there just waiting for me to find it! Fork rebuild time! I have been hoping the forks were one assembly that would require minimal attention; clean-up, fresh oil, and button them back up.
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Started in on the forks and things ground to a halt fairly quickly. Typical Good News/Bad News thing: The Good: I actually own a 36mm socket. Its a leftover from owning a Mini; 36mm socket is required to get the oil filter cover off. (New Mini, not Classic Mini, though I had one of those once as well.) the Bad: The socket has a deep bevel on the inside edge:


And it can't get a good purchase on the nuts on the fork tube nuts:


About my only real option is to get together w/ Levi (@Hurco550) to use his lathe to turn off the end of the socket to get rid of that bevel.

The mess inside the fork gaiter: (and the other side is the same.)


A fork rebuild kit, new set of (correct 11-rib) fork gaiters, and shock bushings have been ordered. Oh boy, more BMW part$!
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In the background I've been trying to find a place to get the clock repaired. Several searches took me to places that do vintage auto gauges and requests for quotes went out. A few places responded, not a single one under $250! I even found instruction on how to take it apart and replace a capacitor or try to realign a couple of coils. Yeah, ok... I searched through threads on the Vintage BMW Motorcycle Owners site and found a place that's got a good reputation, but their quote was $175 to replace the original guts w/ an electronic clock work. I've found an appropriate 12vdc clock the right size for about 1/5th that, so I'll either use that as a direct replacement or maybe if I get real ambitious, switch out the face and hands so it looks original.


I'm not sure if I really want to bend the rim up and then back down again to open it up. One of the guys on the Vintage BMW group had pix of a fixture he made from 2" PVC to close it back together... not really sure I want to go to that length but maybe if I've got time and nothing else to do...

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I haven't gotten w/ @Hurco550 to turn down the socket yet, but I had a DUH! moment and remembered there is a 36mm wrench in the BMW tool kit. (I'll still turn the bevel off the socket I've got one of these days.) I had to spray on the Kroil and let it sit over night, use the heat gun, then give it a few good solid thunks, but I've gotten them loosened up and the left side is partially apart.




The rebuild kit will be in tomorrow so I should be able to get that one rebuilt and back together. The fork seal was really toast so it's no surprise there was fork oil up in the gaiter. Jeez, what a nasty mess; not as smelly and nasty as the carbs, but amazingly sticky and very persistent to cleaning solvents! The replacement 11-rib fork gaiters look short, certainly shorter than the 13-rib that were on it, but supposedly those are the ones that are correct for this year, so I'll fit 'em up and see how it goes.

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Moving along nicely.
Thank you, sir. I try to keep plugging along on it. I've managed to keep the shop temperatures in the mid 50F to mid 40F temperature range depending on the outside temps. The electric heater isn't killing the electric bill too badly, at least so far. Usually a few minutes of running the propane heater when I go out in a light jacket and hat makes things very workable. Usually my feet are about ready to warm up after a couple-three hours. When I bought it @Hurco550 said I could probably count on spending another $1000 in part$. So far I've kept it below that even w/ the big brake investment. I do spend a goodly amount of time in the evenings searching for the best price for part$ and tool$, though.
The fork rebuild kit came in today as expected. It all looks pretty good, it's the EnDuraLast set which seems to be one of the biggest suppliers of BMW replacement part$.


This ia a comparison of the old bottom bumper I took out and the new replacement:


...guess it was almost replacement time.
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I came across another internal bumper that sorta needed replaced:


It's not easy on the mind to take a recip saw w/ hacksaw blade to your expensive-to-replace fork lower, but I want good brakes so I made sure of my measurements and went at it.


I worked away at things w/ a couple files until everything fits up and moves as it should.


And then I couldn't resist a test fit of the caliper.


I thought I took pix of the fork internals as I was putting in the new parts and reassembling, but I guess not; I'll take a couple when I do the other side. Here's the left fork cleaned, rebuilt, big brake ready, and buttoned back up ready to go back on.


There was a set of Progressive fork springs in the box of extras that came with the bike, the originals are perfect and look like new but I'm going to give the Progressives a try. They're about an inch shorter than the originals so that should drop the front by an inch as well. If I don't like that I'll drop in a preload spacer and if I still don't like things I'll put the original springs back in. (It's not hard to do, don't even have to drain the oil.)
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Not much new today. There's lots of cleaning needed before things can begin to go back together. Headlight ears and top triple have to be ready when the reassembly starts.




Right fork tube tomorrow... I hope.
Right fork done today. Everything came apart OK, no problems.

Here are the old and dirty pieces laid out:


That partial bumper in the bottom row of parts; there's only about 1/3rd of it left. The the rest of it was all shredded up to pieces about the size of sawdust and was all over the inside of the fork and suspended in the oil. This same bumper was broken up on the other side as well but was in larger pieces and not completely shredded.

The permanent parts cleaned up along with the replacement components:


Those three rings go into a groove together and need to be compressed while slid into place. Like piston rings, the gaps should be turned 120 degrees apart for a better potential seal. I didn't notice their orientation on the other side but on this side the gaps were all very close together. I don't know if they just ended up that way over time or if the forks were rebuilt incorrectly in the past.

And finally a relatively crappy pix, but it does show that the second leg is buttoned up and ready to mount.


Hopefully I can get the front end buttoned up tomorrow. There's a procedure to getting things set up correctly:

Put the top triple on w/ the nut loosely in place.

Slide the fork tubes into the bottom triple and up to the bottom of the top triple. Turn the nuts through the top triple into the tops of the fork tubes.

Insert the axle into the fork legs and make sure it goes in and rotates w/o binding. Then continue to rotate the axle as you slowly slide the fork legs up and down to make sure there is no binding.

If the axle turns freely and the legs slide as they should, tighten up the pinch bolts on the bottom triple and repeat rotating the axle and sliding the fork legs up and down. If there's no binding, torque the pinch bolts.

Secure the ends of the fork gaiters w/ the clamps and attach the fork brace/fender mount. Check for binding again.

Remove the top triple and install the turn signal stalks and headlight ears with rubber gaskets. Included in this is the task of carefully fishing the wire for the turn signal into the headlight ear housing, around the fork tube, and down through the stalk.

Drop in the fork springs, put the nuts back into the top of the springs and then push down while turning to tighten. Torque the three nuts on the top triple.

Pour the correct amount of fork oil into each tube, screw on and tighten the tube caps.
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Had another productive day. I got the forks buttoned up except for the oil. I'll add that in a bit once I'm sure I've got everything together right. I could have waited on the fender but decided that there's no time like the present, so on it went.


Next comes cleaning and rehabbing the handlebar controls and clean up the crash bar hoop and get it mounted up.
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Back in the day I used to joke w/ my German landlord about the toast: "Viel geld, schönen frauen, und schnell pferden!" (Or is that "Viel frauen, schönen pferden, und schnell geld" or Viel pferden, schönen geld, und schnell frauen?) And I think country singer Tom T. Hall sang about "faster horses, younger women, older whisky, and more money." Anyway, the point is that it's often believed that "more is better." And perhaps that may be true, however I believe there may be one thing that doesn't fit that maxim: GREASE!

I've been working my way around the thing, taking things on as I get to them and today it was time to get into the handlebar controls. I hadn't noticed the condition they were in until I removed the handlebars. While I have come to expect dirt and crud I really didn't expect this:



I don't think I've ever seen grease leaking out of a MC handlebar control but I guess it could be expected when the entire inside of the mechanism has been filled with grease! It's recommended these be kept lubricated but I don't think that's the way to do it. I think there was enough grease inside there to pack an entire wheel bearing.

This is only part of it:


Here's the main body largely cleaned out with just a little final touchup needed. That had been completely packed full of the stuff.


Tomorrow I'll finish that up and go on to the next one.
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