• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

Airhead wheels

prairieguy

New member
Hey guys, I'm picking up parts to do a single sided swingarm on my 83 R100. As I'm fairly new to these bikes, it's lots of learning.
Which (stock) wheels can be used, are there other models in the bmw lineup which have direct swapability?

Sent from my LG-H873 using Tapatalk
 
There are three Airhead single-sided swingarm designs:

1) 3-stud Monolever like the G/S and ST had. They can only accept the 3-hole G/S and ST spoked wheel hub.

2) 4-bolt Monolever like the '85-on bikes had. This is generally the cast drum-brake wheel. The bolt pattern is shared with a lot of later disc-brake wheels.

3) 4-bolt Paralever like the GS, R and Mystic. These normally take spoked drum brake wheels but can also accept cast drum wheels from the Airhead or K Monolever designs.

So, the answer depends on what parts you are using.
 
Thank you very much, this is eactly the sort of information I needed. I have decided to keep my stock swingarm, but I will be switching it to a monoshock setup - using a factory monoshock and some custom fabrication. It should look almost "factory" when it's done.

Sent from my LG-H873 using Tapatalk
 
Trying to get my mind around this......
I've seen this done before. Original dual shock swing arm made to be mono-shock by welding a top shock mount on to the main frame, and beefing up the swing arm itself. In that case you will use a wheel that interchanges with your OEM final drive, which is to say, a wheel with the bearings in the hub. If you want to use a bolt on wheel, use the matching mono-shock swing arm and final drive.
 
Yes, in order to use a single sided swingarm, one must have the correct wheel - which I do not. So, a monoshock on the double swingarm, continuing to use the original wheel to the bike.
In this case, I have a nice set of "snowflake" wheels, so it's a great option.

Sent from my LG-H873 using Tapatalk
 
Hoping you post some photos of this project. I can't quite picture how you are going to use the stock swingarm which is dual shock and make a monoshock out of it. I lack imagination I guess so photos would be great! :scratch
 
Hoping you post some photos of this project. I can't quite picture how you are going to use the stock swingarm which is dual shock and make a monoshock out of it. I lack imagination I guess so photos would be great! :scratch

My guess is some lattice framing atop the existing swingarm feeding into a single shock mounted under the seat/tank. Think 1970s Yamaha MXers...
Best,
DG
 
I have a hub from a 100GS that has been machined to fit the mono swing arm and a 17” rim if you want to put a wire wheel on the bike. I also have a front hub from a 91 GS. Had thought I wanted to either do a “classic style”. mono with wire wheels or put wire wheels with car tires on a sidecar rig I owned. PM me if you want more info.
 
The one that I saw was owned by a rider from Wisconsin. It looked a lot like a mono-shock set up and he simply pulled the left shock. Of course, he also used a longer shock on the right side. His set up left the single shock slightly closer to vertical than a post '85 bike. Again, the upper shock mount was welded to the main frame. OE seat sub frame was removed and replaced by a custom made sub-frame.
 
The one that I saw was owned by a rider from Wisconsin. It looked a lot like a mono-shock set up and he simply pulled the left shock. Of course, he also used a longer shock on the right side. His set up left the single shock slightly closer to vertical than a post '85 bike. Again, the upper shock mount was welded to the main frame. OE seat sub frame was removed and replaced by a custom made sub-frame.

That sounds like a formula for a lot of swingarm flex and odd handling characteristics. Not that a lot of “form over function” designers would factor that into their considerations...

Best,
DG
 
That sounds like a formula for a lot of swingarm flex and odd handling characteristics. Not that a lot of “form over function” designers would factor that into their considerations...

Best,
DG
I only observed some one else' s assembly. I did not have a chance to ride it, nor would I recommend that sort of fitment.
 
I only observed some one else' s assembly. I did not have a chance to ride it, nor would I recommend that sort of fitment.

Oh, I wasn’t by any means commenting in a negative way on you or your observations and hope you didn’t take it that way. I was only observing that a setup such as you described presents a lot of functional problems that would need to be addressed and that such issues often get overlooked or ignored by builders focused on a style or “look”. I seem to remember Fred Rau writing in one of his articles that he’d had a first-hand viewing of some Orange County Choppers; he proclaimed them to be “Orange County Crap” due to functionality and QC issues he saw. And lately we’ve all seen an increasing number of custom builds based upon old Airheads; some are really nice designs and well-executed in both functionality and build quality, and then there are others. Hopefully the OP in this thread will build one of the former and not the latter.

Best,
DG
 
No worries DG, I just did not want to be seen as endorsing that kind of set up, even though I know of a working version of the same. The pictures that Anton linked show a good way to achieve that kind of modification.
 
Thanks for the comments and pictures guys. This is exactly why I posted my plans for my bike. I very much want to have a machine which is a pleasure to ride, and certainly safe too.
Aesthetically, I'm trying to clean and lighten the appearance of the bike. The factory single sided swingarm does this perfectly. These bikes also have a great reputation for comfort, performance and safety. So, taking all the points given into consideration, a swap to a factory "single" setup is really the way to go - I'm certainly not going to be able to out-engineer BMW!

Sent from my LG-H873 using Tapatalk
 
I certainly agree that modern bikes are more powerful, have better brakes, and are very highly engineered and styled.
Fitting a vintage airhead with better/newer technology is something I'd love to do, but probably not on this bike. I'm really just learning how to work on them, so familiarity with how the stock parts interchange is a big deal.


Sent from my LG-H873 using Tapatalk
 
Haven't had much experience with the '85-on single side bikes until recent weeks when we've come upon an '86 R65 for restoration.

The top shock mount is a piece of iron welded to the frame. I'm fairly certain from other experience that the oval tubed frame is not exactly the same as previous dual shock airheads (there is no oil cooler thermostat clearance issue).

In any event, this uses the four-bolt wheel and you'll only find one with a rear drum brake.

Also in any event, I'd predict any shadetree effort to convert an earlier bike to single side will result in ZERO performance improvement.
 
Back
Top