New Member Question and Intro 1975 R90/6

Thanks Kurt. I saw the same thing as you, that Ikon shows different part numbers. Possibly different size posts, distance between the eyes or load capacity.

Too bad, the used shocks were very reasonably priced.

I may go ahead and ask the seller why he thinks they will fit earlier airheads, I'll keep you posted on his response if I get one.

Regards,
Larry

The LWB models had shocks that were around 335mm eye-to-eye or 13.2 inches. The R65 shocks are about 0.5 inches shorter. Using a shorter shock is going to do some nasties to the handling of the bike.

20774 said:

The LWB models had shocks that were around 335mm eye-to-eye or 13.2 inches. The R65 shocks are about 0.5 inches shorter. Using a shorter shock is going to do some nasties to the handling of the bike.

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Unless you also lower the front which is usually quite easy to do.

That's a very good reason not to purchase/install the R65 shocks and exactly the information I was hoping to get.

While lowering the front would be possible, I'd like to experience the bike as it would have been straight from the BMW factory, exactly like I'm doing with my MGA.

Thanks so much, I love this forum!

Larry

20774 said:

The LWB models had shocks that were around 335mm eye-to-eye or 13.2 inches. The R65 shocks are about 0.5 inches shorter. Using a shorter shock is going to do some nasties to the handling of the bike.

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Progress!

Puttered with the bike tonight, I think I found the problem with starting. Actually, two problems - the starter relay seems to have decided it was tired of life and checked out plus the ignition (points) seems to have somehow gotten stuck open. I pulled the mechanical advance off and played with the points and when I put it back on I suddenly had spark again. Possibly due to the advance rotating on the shaft so I'm going to try my trick of filing a flat on the opposite side of the camshaft to lock it down.

I started it by jumpering across the solenoid with a remote starter switch. Fired right up - insert big grin here! Put on a helmet, rolled it off the kickstand and drove under its own power for likely the first time in over 20 years. She has at least 25 year old tires, no front brake and no instrument lights, but darned if she didn't take me all the way around the block!

On the schedule - new tires, new spokes, fix the dash and brake lights, get the neutral switch working (before the starter relay died I had to hold the clutch lever in to start it), rebuild or replace the master cylinder and brake calipers/pads and install the new starter relay.

It was a good day!

Larry

Nice! Keep checking off the list!!

Continuing in the vein of checking off the list, I just received a replacement for my center stand (sincere thanks to Chip Seltzer) and plan to put install it ASAP so I don't have to keep a 2x4 under the missing part of the left leg.

Could one of you fine folks who have a /6 do me a big favor and give me some dimensions on the side peg that's used to push the stand down to the ground? The stand I received has been modified to beef up the easily broken arm but I'd like to put it back to stock appearance.



I need the thickness of the rod, overall length and length to the bend in the arm so I can fab up a replacement. The one that's on there actually looks like some thought went into it but I'm going for a restoration and would like it to look original. Plus, I'm not really digging the threads left over where the arm attaches to the leg.

Thanks in advance to anyone who can help out.

Larry

I use 1/4 rod. Grind off all the excess slag from before. Drill a 1/4 hole through both sides of the stand in the location closest to original. I can't remember how long the rod has to be but around 7 1/2 in. should do for a start.
Weld both sides to make rod flush on inside and try to duplicate factory on outside. Mount stand and put in up position. Heat rod at the point where it is under and just to the outside of the muffler. Start bending but don't go too far. You want a gradual arc so let it cool and heat another inch out from that. Keep going until you have the end almost vertical. If it liiks too long then cut to fit. I use a disc to round off the edge.
I also use a 10mm box wrench over the rod to do the bending. Clean it all up and squirt some gloss black on it and you're done.
It helps to have a bike near by to judge the curve but in the end, unless someone is judging you and comparing your's to their's I doubt if anyone will notice.

BoxerBruce! You're my hero!

Great information and exactly what I need. I think I may have some 1/4" rod on hand so extra bonus.

Larry

Two steps forward!

Had a nice surprise when I got home tonight, had a box from eBay containing a new turn signal to replace a broken one and a package from Motorrad Elektrik with a replacement starter relay. Installing the turn signal was a piece of cake but the relay was a little more confusing. The aftermarket relay from Motorrad has three fewer spade connectors so it took me a few minutes to figure out which wires to put where. I had to leave one black wire off, but once I put wire back on the starter the bike started with one push of the starter button. Woohoo!

I was able to put the starter cover, front engine cover and tank back on so it looks like a bike again.

On to the front brake, the brake light (neither front or rear work) and the dash lights. I'm heavily leaning toward the Katdash mod, but would like to see the current panel at least get power.

Thanks to everyone for the help so far.

Quick update, I spent some time fussing with the electrics on Saturday. I won't be able to test the front brake light until I get the master cylinder rebuilt but I did find that the rear brake switch was very crudded up and not moving. I drilled out one of the rivets and was able to rotate the bottom cover to the side. I cleaned up the inside with some electrical cleaner and got it working by bending the contacts up a bit.

The tail light started working by jiggling the wires in the taillight assembly, obviously bad contacts.

I pulled the dash apart and found most of the bulbs were dead. Replaced all the bad ones but still don't have many lights working (only the generator light comes on when I turn the key to 'On'). so I have more work ahead of me cleaning the bulb contacts.

The horn came to me in a box. Still need to install it and figure out why I don't have any power to the wires when I press the button.

Another bite of the elephant . . .

Had some fun last night stripping the paint on the air cleaner emblems. The left wasn't in too bad of shape but a PO had decided to do his own paint job on the right side. Not to my taste so I soaked them both with aircraft stripper and repainted with some gloss black Rustoleum.

I got the paint off the letters by using a dab of paint thinner on a piece of old sheet and gently rubbing the paint off. Turned out pretty good if I do say so myself.



The PO's paint job.



Pretty sure that paint was his take on a Grateful Dead bike as evidenced by this:

What's wrong with the Dead!! Were you able to lift the sticker to reveal the rest of the roundel?

Nice work on the engine badges.

Absolutely nothing wrong with the Dead! But the badge was painted - let's say - less than professionally.

I peeled up the Dead sticker on the left side roundel and yes, the blue and white are under there. Pretty trashed though as some fairly strong glue was used which means I either leave the deadhead on or buy new roundels.

I only put one coat of paint on the engine cover badges as the chrome is pretty bad and I'll need to strip it again for re-chroming when I get around to the full restoration of the bike. Got a lot of chrome that needs help, I'll have to decide on what to replate and what to replace.

20774 said:

What's wrong with the Dead!! Were you able to lift the sticker to reveal the rest of the roundel?

Nice work on the engine badges.

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Master Cylinder Question

I have another question regarding the front brake master cylinder. I need a rebuild kit and Boxer2valve.com lists four kits. The two for the 1974-1975 R90/6 are listed as 14mm or 16mm and states the size should be stamped on the existing master cylinder. I've looked it over extensively and can't find any stamping. There is a raised letter 5 on the body and the number 145 on the arm that pushes the piston in, but I don't see a 14 or 16 anywhere.

Since the 14mm one is $35 more than the 16mm, I'm sure that's the one I'll need, but . . .

Any suggestions on which kit is the correct one? There's a sale going on right now that I'd hate to miss.

Thanks in advance,
Larry

Larry -

Brook had a good write up when he rebuilt the master cylinder on his '77 R100RS. He showed the cylinder and the stamping on it to indicate the size. The picture was here:

https://www.flickr.com/photos/brook-reams/32719523874/in/album-72157675789624605/

His full page on this was here:

https://brook.reams.me/bmw-motorcycle-rebuilds/1977-bmw-r100rs-rebuild-project-index/

RealOEM says 14mm is the size...probably for single disk brake. Maybe 16mm is for dual disks?

Thanks Kurt, I'll have to take a wire brush to it and see if I can spot numbers in that area.

I checked a couple of other vendors and they only offer the 14mm so that's what I'm going with.

Once I get the front brake working all I need is new tires and the bike will be nearly ready for the road!

Larry