TRIPLE SHOT, SIR?

The triple pots, you see, with equal 120 degree spacing on the crank, deliver an engine note that can't be found on any single, twin, or four-cylinder motor, and I also quite liked the idea of building a cafe racer with shaft drive, rather than a chain (no oil flicking up over the rear wheel). The XS has, as standard, a 110mm rear tyre, though, and I wanted at least a 140tyre to enhance the look, so that was a problem to solve. I started with a '77 bike that I bought on eBay for £700 from up in Yorkshire. It wasn't roadworthy, and had a number of oil leaks, but more concerning was a serious knocking noise from the engine. Another problem to deal with ... As I wanted the bike to have a racing stance, I changed the front wheel (a 19-incher) to an 18" from an RD400, which also had twin rotors, and used R6 discs, and Brembo calipers from a Monster, and I shortened the original forks by 2" to lower the overall centre of gravity, and to keep the bike parallel to the road. I shaped the exhaust so that the three headers ran tight against the engine's underbelly between the chassis tubes to give better ground clearance, then brought them into one just before a 90 degree bend up between the engine and the swingarm with just enough room to do so. I then fed it into a canister-style baffle located in the centre of the frame where the old (enormous) battery used to be, installing circular deflector plates inside to increase back pressure and, to finish off, I then split the exhaust back into three tail pipes. Having used the battery space, mounting the battery was a challenge as there was no room under the tank, and very little space under the seat if I wanted to maintain the stripped-down, naked look. So I purchased a 12-cell-Ballistic-lithium battery, and mounted it under the tail piece, just above the exhaust tail pipes, using

a heat deflector to prevent heat damage. One of the problems with lithium batteries, you might not know, is that often old motorcycle regulator/rectifiers'll allow them to over-charge. To overcome this, I replaced the old reg/rec with a more efficient Mosfet-type which can be found on Yamaha Rls. For the seat unit itself, I created a mould using builders' insulation foam to model the shape, trimming it with an electric kitchen knife, and smoothing it off with sandpaper, and then completed the base of the seat using fibreglass and resin. The shape I had in mind was reminiscent of an early Jaguar or Porsche from the rear, but also wanted to give the bike a modern twist by bringing the tail pipes out above the rear wheel like the MotoGP Ducati, for example. To finish it off, the seat pads were trimmed in diamond-shaped quilted leather, with purple stitching to match the colour scheme. I replaced the rear twin shocks with modern YSSadjustable ones, and notched the swingarm to take the larger rear tyre by cutting a section out of it (the swingarm), and machining a groove out of the drive shaft to allow the tyre to fit. Problem - solved. I used an Acewell all-in-one speedo/rev counter unit, with various warning lights/ engine temperature/ambient air temperature sensors, and upgraded the ignition system from points to electronic. A loom was made from scratch to help keep wires to a minimum - I installed a MotoGadget M-unit Blue which acts as a central junction box, incorporating all relays and fuses in one unit, and it's linked to my iPhone via an app, allowing me to make adjustments and monitor the running performance of the bike. For the headlight, I chose an old '60s-style bullet-shaped Lucas housing, and fitted a stone-guard to give it a retro look. I also wanted the bike to be keyless so fitted one of the MotoGadget proximity ignition switches (M-lock), placing it behind one of the Yamaha tuning fork emblems on the top yoke, and had a bit of fun with the mechanics at the first MOT - I set them a challenge that anyone who could find out how to start the bike could have it. The bike, you'll be glad to know, is still in my hands! Finally, the last job to do was a full stripdown and rebuild of the engine, replacing many parts including the main Hyvo chain (which was what was causing the knocking). The carbs were re-jetted, to balance the highflow air-filters and bespoke exhaust, and that completed the work. The XS cafe handles really well (although the dual-sports tyres are cosmetic, rather than practical for racing), and the suspension, and seat, are more suited to track rather than UK roads but, overall, I can't help smiling along every mile I travel on this nostalgic Yamaha - it reminds me of my youth, and draws attention at all my favourite Peak District watering holes.