As per the rules, the frame must remain as standard, as have the engine cases and crank. Pretty much everything else can, and has, been swapped for aftermarket and JHS Racing homemade goodness. This is a bike that’s been several years in the making.
The JHS Racing SV650 looks as good naked as it does fully clothed...
ALESSIO BARRANTI AND STEFFANO GADDA
JHS has developed a Triumph 675 intake that fits snugly to the SV’s headstock. Forced air volume is at least doubled over the standard. The true magic lies beneath the tank and if we printed what was under there, we’d be sleeping with the fishes.
The eagle-eyed amongst you will spot this SV wears a complete 675R front-end. A little stem modification, and the Triumph yokes, forks and wheel slips on nicely. The Öhlins internals have been revalved and shim stacks adjusted. The length of the fork stroke has been lengthened to aid balance.
The ECU has to remain standard, but the loom is open to all sorts of, er, openness. JHS has used its experience of racing Minitwins and developed a loom using CAN-line technology. A Translogic quickshifter sharpens the shifts, while a super-light and heavy duty battery ensures the fuel injection system can fire the juices. As the year progressed, a lot of the unnecessary goodies were removed because of complications, like datalogging.
The front fairing and bellypan are, you guessed it, slightly modified Triumph 675 plastics. The seat unit is a ZX-10R, commonly mistaken for a Fireblade’s.
The big difference between the TT bike and the short circuit bike is the gearbox. The ‘factory’ bike has a close-ratio ’box that allows for not only higher terminal speed, but better acceleration. The standard gearbox has country miles between certain gears, which makes gearing for certain tracks a friggin’ nightmare. Sigma (as in Neil Spalding off of the Eurosport telly box) designed and manufactured an SV-specific slipper clutch to cope with the 30 per cent extra power. Engine braking is so fierce, clutch wear was ruining a race weekend...
In its fifth generation, the JHS lump has severely gone under the knife. As previously mentioned, all that remains from the standard lump is the crankcases and the crank itself. Everything else is made in-house (pistons, con-rods etc), and with hours of head work and valve detailing, James has now found the limits of the internals.
The standard swingarm has been modified to house a 675 rear wheel, and is supported by an Öhlins shock that’s been built specifically for this bike. An underslung brake caliper speeds up rear wheel changes, not to mention makes the process much easier. Various linkages have been tested but the standard linkage rate seems to work best. And a new swingarm will be fitted for 2013.