The Background:
I have a '84 R100 BMW Ural set up that was done by Perry Bushong. I bought it on Ebay not realizing it had 16" rims, front rear and sidecar. Then the fun started. The bearings were shot in the rear wheel. Wrrking on that we found out why. Somewhere in it's travels, the swing arm had been "modified." Squeezed in a vice or or power press to make the cutout on the drive side big enough to accommodate the wider tire. Unfortunately, they were none too careful with making sure that everything remained aligned. The swing arm was canted and the holes for the ends of the axles were not in line. Some used the bigger hammer method to drive the axle in. To sut to the chase- I've replaced the swing arm and replaced (and relaced) the ruined hub. But I refuse to bend my new swing arm so the 16" rim doesn't fit. I'm running a spare 18" wheel in the meantime.
The Question:
If I were to readjust the spokes to give me an additional half inch of offset on the non-drive side, I could use the 16" rim. Does anyone have any experience with more radically asymmetrical spoke set ups? Thanks
Photo of an unmodified swing arm here:
Back in the 90s, CC Products (or was it Luftmeister?) used to lace up rear wheels asymmetricaly to fit wider sport tires. I'm sure it was more than a half inch offset. I'll check my old print catalogs and see if there is any more info.
I have run offset front wheels with no bad effects on sidecar rigs in the past. All you would be out if it was problematical would be the labor (and maybe a spoke kit). I'd go for it.
L.
I found my 1988 Luftmeister catalog. They laced up a 3.5" x 18 DID rim so it would take up to a 160mm wide tire. The ad says that the rear drive has to be removed for installation - I guess the tire is so fat it won't fit between the drive and swing arm. No mention of the exact amount of offset but the stock rim width is either 2.5" or 2.75" depending on model. Stock tire size is either 4 inches or 120mm wide. That implies that you could get at least a .75" wider rim.
Thanks for the reply. The offset I would like to get is an additional .5"
If you have a 2.5" rim, you could probably get the .5" you're looking for. If you have a 2.75" rim, you probably won't unless you widen the swing arm.
