Transforming a BMW 80G/S airhead oldie into a light and durable DS bike

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DirtyHarry

Race Dog
Joined
Dec 23, 2009
Messages
2,750
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Location
Cape Town
Bike
BMW R80GS
<<< Caution, this thread is classified as an airhead related post. Please don’t move >>>

It has been done before and there are different ways to make a 80G/S more off road capable. My attempt will not challenge any of the so perfect HPN projects from DD. He builds his bikes in another league.
Done the right way, a fully upgraded and restored bike will easily cost as much as new 1000cc bikes cost these days. The bike I am after does not need 100hp and must not be in show room condition. Practicality is the key for me when it comes to dirt bikes. The main focus will be put into a suspension upgrade but I will not bling the hell out of the old lady.
This bike should be reasonable light in weight ( +- 185kg )  with very usable torque figures and should be easy to maintain and repair. I would like to use this bike in places, where my 1150GS can only go with difficulties.
My 80G/S was built in 1980 and the previous owner has started the conversion at the right places already.

The frame has been strengthened at the well known weak spots.
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The swing arm was extended 100mm and a cross bar added for extra strength.
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Single seat is fine for that purpose, for anything else I can use my 1150.
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Next I do establish the rear suspension travel.
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My calculation comes to 225mm at the rear. The front forks I probably will limit to 260mm.
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I will have to fabricate a bracket on the swing arm to accommodate the rear shock.
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A bracket had to be moved and a bit of cutting on the seat was required to get the rear fender further forward.
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This is my cheap and light weight solution to mount the rear indicators without an extra bracket.
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