Another one of those rebuild stories R50/5

[barrettnjones]

Here you can see the new oil cover with the hex head bolts hiding behind the flywheel.

[barrettnjones]

Christmas came early this year. Got my frame back from the painter. Here's a before and after on the swing arm.

[barrettnjones]

Here's a before and after on the frame. Ray Atwood in Bolton, VT does amazing work.

[barrettnjones]

Here's a link to a photo journal of this whole process so far:

https://www.icloud.com/journal/#p=01....jb/index.json

Anyone know what the 2 is after the date on the engine casing??

[lmo1131]

Just a guess based on having worked in a foundry, and having spec'd some cast parts over the years as a designer.

The mold that made these parts is made out of sand. Once the metal is cast the sand mold is broken to remove the part(basically one mold per part is needed)

The sand mold is made by ramming the sand down onto a duplicating pattern. The pattern is removed leaving a cavity behind where the pattern was. The mold is now ready for the molten metal to be cast into it.

Since sand is abrasive it eventually starts to cause wear on the pattern, and the pattern (usually aluminum (previously wood)) can be damaged in handling. The "2" may be an "identifer" to help maintain casting quality if a recurrent flaw starts to show up in castings. In this case it would be pattern number 2 that has some damage that is causing the sand molds to transfer flaws onto the parts. There would have been many "pattern sets" to produce the high number of molds/parts BMW needed on a daily basis.

If there were no "identifier" it would be time consuming to have to check all of the duplicating patterns to find the damaged one.

The date is more than likely the date the pattern was made, not the date the part was cast.

There is a separate mold for the opposite side.




Or not.

[barrettnjones]

What's this allen screw under the oil pressure thingy??
There's also an allen wretch screw around the back at the bottom facing the tranny.
????

[20774]

That plug closes off a manufacturing galley. It never needs to come out or it should never leak. If it does, then you'll need to remove it and secure it. Snowbum mentions red loctite.

[barrettnjones]

Just got a parts order from Hucky came in the mail. Luckily I have the place to myself this weekend so I can spread out and get organized.

[barrettnjones]

How bout some new bearings in the swing arm? Ed Korn's tool was every bit as helpful on installation as is was during disassembly.

[barrettnjones]

Headset together with fresh wiring for the front turn indicators.

[barrettnjones]

Shocks in place

[barrettnjones]

I just had to see it with the tank back on. Moving towards the ass end next in order to get a rolling chassis and back in with the engine.

[barrettnjones]

Swing arm all aligned, sub frame on and rear suspension in place. These Redwing shocks came with the bike when I purchased it back in July. They were brand new when installed last summer so I'm going to continue to use them. I like the way they look and I like how firm they are.

[20774]

Redwing shocks?? Never heard of them...shoes, yes. Looks like they have dual rates springs?? What's the big "bulge" at the bottom all about...just to be different?

[barrettnjones]

Redwing shocks?? Never heard of them...shoes, yes. Looks like they have dual rates springs?? What's the big "bulge" at the bottom all about...just to be different?

I don't know much about them honestly. I can share what I've been told though. The guy I bought the bike from said these are shocks from the early 70's which I thought seems pretty authentic considering what they're on. He also threw in another, softer pair that are also unused. I think I'll keep the firmer one on for now.
The bulges on the base of the shocks are there to help make me go extra fast around bends in the road!