R80ST vs. R80 Monoshock Suspension
 

Just saw this ad on ebay. Just wondering.

The owner converted an '86 R80 to a R80ST look-a-like.

http://cgi.ebay.com/ebaymotors/1986-...item2ec4bd0dce



Are the frame and suspension setup the same between R80 monoshock and R80ST? Are parts interchangeable between these 2 bikes? Can you put an R80 monoshock rear wheel on a R80ST?

Thank you for the reply,

TT

I think an R80RT of that era would have been monolever from new so it has not been converted, the spoked rear wheel will not fit as it has three bolts and the monolever one has four. Apart from the insruments there is not much ST about this bike, it still has twin silencers and the right hand silencer mount is not there on the ST frame which is which another difference.
This does not mean it is not a capable machine, a friend of mine has done the same to his monolver RT and loves the bike but if you want an ST you will have to buy one as this is nothing like it.
From what I can recall the only parts that are the same are the engine and gearbox, just about everything else is different.

Subframe is different
Three bolt vs four or four vs five rear wheels.
Shock mount point at the frame is different too. At least the r80 uses the big battery and the st uses the smaller one.

I've got one of each in the stable.

Squish mentioned the upper shock mount being different, but the lower one is also different. The shock mounts to the swingarm on the ST (same swingarm as G/S) whereas it mounts to the the final drive on the later mono models.

Also, the ST frame is based on the R65 monolever frame with a few little changes. (that's why R65 gas tanks will fit the ST and G/Ss)

Funny I though the Mono R65 was the same frame as the Mono R80 and the ST was the same frame as the G/S...

The ST IS the same frame as the G/S. The mono R65 didn't exist when the G/S and ST came out.

Oops, I stand corrected on the R65 mono part. I had mis-remembered the description in Zimmerman's BMW Motorcycle Buyers Guide where he describes the origins of the G/S then the creation of the ST as a street version with forks and frame similar to the R 65 with the use of the mono rear end on the ST.