You will need to check into weather the /2 rim will lace up to the /6 hub. I have tried to lace a /2 rim to a /5 hub and found the lace pattern wouldn't work, at all. What you may end up doing is lacing a /5 or /6 rear rim to your hub. That way you will have both 18 inch wheels. If spoke length is a problem, contact a place like Buchanan's, they will likely have something available for you to use.
Looks like an interesting project, just remember that the steering stem on a /2 is longer than a /5 or /6. If you are able to secure a US model lower yoke, that should cure the problem or use a US stem in a /5 or /6 lower yoke. Either way you go, you will still need to use a US steering damper as the steering stops are built into the lower damper plate, or just make up something yourself. Without any steering stop, you will eventually damage the gas tank.
It may not be "sensible" nor economically feasible, but you should know that any 1938-54 BMW twin front end will easily mate to your R60/2 mainframe, and you can lace a 18" post 1955 BMW wheel rim to an earlier '38-54 hub. Of course, you need to use the earlier brake plate and "steering damper lower plate". (to use pokies term. I don't know what the official word is, but you get the idea). As with all things BMW, an early front end is EXPENSIVE, and somewhat hard-to-find, and your competing for it with the living room display only crowd!
Those bikes in the style posted are referred to in some circles a "hipster bull****" bikes,lol. Taking perfectly good bikes and turning them into retro-style cafe wannabe racer bikes. All you need is header wrap and flat black paint. Some come out pretty nice,but I have seen some turds.
I am just quoting many comments I have read on vintage BMW pages. They all end up looking the same,with small/no fenders/drop bars/cafe seat/retro header wrap/blacked out/fat tires/etc... and some do look GREAT,but some are turds. But here is a nice one. I would ride the hell out of this bike. Isn't it a wonderful thing, that we are all different, and like different things?
The purpose for these fake BMW or "bitsa" are to have a framework on which to hang all the second quality/weirdo/orphan parts that don't fit anywhere else? If you should need a part for a more valuable bike, you can just steal it off the fake!
I am just quoting many comments I have read on vintage BMW pages. They all end up looking the same,with small/no fenders/drop bars/cafe seat/retro header wrap/blacked out/fat tires/etc... and some do look GREAT,but some are turds. But here is a nice one. I would ride the hell out of this bike. Isn't it a wonderful thing, that we are all different, and like different things?
Seriously, how roadworthy would this thing be? Interesting to look at, as a kind of techno-sculpture, but does it have any worth at all as a real motorcycle? (I know, I know, I'm missing the point!)
Jon Miller
'67 R69S
'13 F800GT
Altadena, California
I do think a nice conversion can be built, I also think even a turd can be brought to a likeable point. If a bike is being created from junk or if a bike is being brought back to ride-able condition from the dead, then why not? What I do disagree with is taking two perfectly ride-able bikes and trashing them both to make one monstrosity, that's just wrong.
Like everybody else here, I have seen some nice conversions and I've seen some real turds, BUT if you are going through contortions just to put another BMW back on the road from nothing, I'm all for it.
If embarking on a retro conversion project, every issue of BMW Motorcycle magazine features at least 10 of them. Seems to be the main theme of the magazine (fortunately or unfortunately). Regardless, there is plenty of inspiration. I personally don't care for them, but to each his/her own. As Stephen points out, its an opportunity to make a bike from lots of spare bits.
As for the frame in question, since its not a matter of matching numbers, I would ditch it and find a better replacement. There are plenty of orphaned frames out there for not much money.
I know this thread is kind of old but if you're interested, I have the task of dealing with a couple of damaged frames. Maybe I could cut part off part of one of the frames that you could replace the offending portion of your frame or you could just take one of the damaged frames and have it straightened. From what I can tell, the damage is at the rear portion of the frames, bent shock towers. Shipping will be unpleasant but it may answer your problem. Let me know if you're interested and I can have a better look at the frames, maybe even take some detail photos for you. I have a lot of parts to go through, so if there's anything else you may need, let me know and I'll keep and eye out for them. You may contact me off line at metalfab54@yahoo.com