Join Date: Aug 2016
Location: Coronado, CA NASNI
Lowering first gear in a 1200GS is a very tough endeavor, to date I have not heard of anyone accomplishing it but where there's a will there's always a way, it was a fairly common modification made to R100's and older BMW's.
You have to figure out which gears or gear-sets would need to be swapped out (intermediate and/or output shaft gears) and for what size and than you'll need to find those gears which is likely to be the hardest part.
I would start by contacting companies like HPN (HPN-Motorrad: Engine & Gearbox
Another option would be to replace the rear tire with a smaller diameter tire, this of course would only provide a very slight difference.
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