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1938 R66

Posted: Sun Jun 19, 2022 10:42 pm
by Mark E. Turner
Hi - I'm a new member who was lucky enough to acquire a 1938 R66 from a friend. I'll be getting the bike in pieces and will be building it but I'm not knowledgeable in early BMWs. I'm hoping I can ask the group for help in answering my questions. I'll be posting photos as I go so if anyone notices something I am doing wrong, or if there is something wrong with a part, please let me know. More pics to come.

Re: 1938 R66

Posted: Tue Jun 21, 2022 7:28 pm
by R68
Good for you! A very desirable BMW...take your time and do the good restoration it deserves?

Re: 1938 R66

Posted: Sun Jun 26, 2022 10:13 am
by sherman980
Mark,
Can't see from the pics you posted but do you have sheet metal (tank, fenders, etc.), and, if so, what kind of condition is it in? If it's decent, I'd be tempted to put the bike back back together restored mechanically but with the the original finishes on all the parts. If nothing else, you can ride it a bit and sort out the "bugs", then take it down for a cosmetic restoration. I have both complete restorations and original bikes in my collection, and, honestly, I enjoy riding the originals more. Just one guy's thoughts.....

I've attached a couple of pics of my 1936 R5. It's pretty much become my daily "rider".
DSC04154a.jpg
DSC04128a.jpg

Re: 1938 R66

Posted: Tue Jun 28, 2022 10:15 pm
by Mark E. Turner
Thanks for the comments.

Here are some more pics. Ran into my 1st problem. Check out the triple tree lower - is there another model that has the same lower triple tree? Thanks.

Re: 1938 R66

Posted: Wed Jun 29, 2022 2:59 pm
by caker
Hi,

Your lower fork triple is an original EARLY prewar type which was replaced with a re-designed version used all the way from late prewar through 1955 on the plunger bikes. I'm guessing it was redesigned to improve strength or eliminate failures in the early design...

Yours looks to have failed and then has obvious signs of repairs made.

Here's an example of an unmodified early original one like yours was:

forklower.jpg

-Chris

Re: 1938 R66

Posted: Thu Jun 30, 2022 2:50 pm
by R68
I think you may be able to substitute a triple tree from an R50/2 or 1951-52 R51/3, both of which use the desirable metal fork gaiters as your's...

Re: 1938 R66

Posted: Tue Jul 05, 2022 12:30 pm
by Mark E. Turner
Thanks Chris and R68 - your comments are very helpful and i'll be on the hunt for those.

Re: 1938 R66

Posted: Tue Jul 05, 2022 12:36 pm
by Mark E. Turner
Hi everybody. This project is remarkably complete. I'm not missing very many parts and I have 60s and 70s BMWs but not anything early. Hard to find anything on the internet so if anyone has any sources that would be great. The period manual doesn't even show a R66 engine. More pics to come. Thanks. Mark

Re: 1938 R66

Posted: Tue Jul 05, 2022 2:31 pm
by caker
Mark,

For prewar plunger bikes, your best bets are:

Mark Huggett out of Switzerland. He is the source for MANY parts for all BMW bikes, and is affiliated with BMW Classic:
- https://www.bmwbike.com/

Second to that, Bench Mark Works which is now Max BMW, offers many of Hugget's parts here in the US
- http://www.benchmarkworks.com/ (you can still order from this website, it goes to Max BMW now)

Oldtimer Garage:
- https://oldtimergarage.eu/gb/45-r51-r61-r66-r71

RRC-Tuning has R61/R66/R71 rear main bearing carrier, which has inevitably spun and needs replacement:
- https://rrc-tuning.com/?cat=c159_BMW-R5 ... 6-r71.html

There's a fair amount of overlap with postwar plunger bikes, so things like fork parts and so on will work. I really like Vintage Beemer Parts on his website and on ebay:
- https://vintagebeemerparts.com/
- https://www.ebay.com/str/klassiccyclestuff

There are others, but it may depend on what you're looking for...

Cheers,
-Chris

Re: 1938 R66

Posted: Tue Aug 30, 2022 8:22 am
by niall4473
The Chiang Jiang CJ750 which went out of production about 20 years ago in China used a bottom fork yoke indistinguishable from the 1938/9 R51/61/66/71. I used to have a set of these forks and with the very rough shrouds taken off, apart from the steering lock being absent, they were identical, and not as badly made as is often made out.
Not too difficult to find and much cheaper than original pre-war BMW.