Dust MC Twin-Stroker
By Ross Sharp - 01 Oct 14
Dust Motorcycles is the outlet for Steve Bentley and his addiction to BMW customisation. So far this year he has brought us the Gunshot, the one with the Husky tank and the Dales Tracker; both with leanings towards muddier roads. This time a more Tarmac biased build has been commissioned. The photographs show cobble stones so I can only presume proper roads have not made it that far North just yet, surely just a matter of time and a fairer spread of government funding.
Steve was under pressure from the outset as the customer commissioning this build is a decorated military marksman, not only would such a client be used to precision and attention to detail but not someone to take too kindly to unsatisfactory craftsmanship. Lucky then that things started off well in the form of a 1983 R100RT donor, with a piffling 32k miles on the clock and service record as well stamped as the new owner's rifle range score card. The brief was relatively simple; comfy leather seat, a small tank and proper top speed.
Steve started with the engine, aiming to improve efficiency and ensure the small amount of fuel on board was not squandered. An unleaded conversion to twin spark cylinder heads was the simple answer. Both Motorworks and Motobins offer the service on either new or exchange basis. A 20% improvement in mixture burn rate can be expected which makes a real world difference on a bike of such heft, sporting such a tiny tank. New Airhead rocker covers left bare look smart against freshly painted heads and barrels. The Bing carbs were rebuilt and new cables added. The gearbox was leak free and in good order so treated to fresh oil and left alone.
The frame had the obligatory strip before receiving a good coat of gloss black, along with wheels to match. Heindenau's ever popular K60s were fitted, which should offer plenty of purchase on those slippery Northern cobbled streets, should a Hovis delivery boy swerve into the BMW's path.
To ensure new owner Paul is given correct updates on his progress and arrives on time an Acewell speedo was fitted, just above a matt black 7" headlamp. Bars are US-spec Triumph, modified to accept the original BMW controls.
Steve's Yamaha RD fuel tank collection was raided once again, and this is the blue one. Should Paul's missus require whisking to the ball and her gown is a different colour, no problem, just change the tank. Yes, thats right, Paul has three different tanks and selection seats to suit the occasion.
The front mudguard is a shortened stainless item mounted to the stock bracket on original and unmolested forks; well apart from the removal of paint and the horrid orange reflector. Koni shocks keep the rear in check and smooth out those cobbles. Brakes too are standard, refreshed with new seals and fluid.
A fifth generation shoemaker was enlisted to fashion covers for the selection of seats, using the finest leather available to him. Above is the black one, I presume there are various brown tones available to match foot attire. The slim RD side covers have been attached and removed several times until Steve decided that they balance out the bulk of the BMW's profile.
Simple reverse megaphones improve acoustics and are visually just the right length. Simple LED indicators and a low mounted mirror keep the MOT man happy. Apparently though a law or two might have been flouted as the indicated 107mph top speed was not quite up to Paul's expectations. A Ducati build might be on the cards.
All in all some simple mods and a tank swap have turned an ungainly eighties snow plough into a taught looking bike, with plenty of shove and enough customisation to turn heads. Nice work Steve, and don't forget to send us pictures of the Ducati.
Keep an eye on his progress over on Facebook or see more from Dust Motorcycles here on The Bike Shed.