With a fully faired sportsbike called the GP Sport and the pared-back nakedbike called the GP Street, Spirit Motorcycles said the models “bridge the gap between the real world functionality of large scale- production bikes and the outright performance of true racing machines.”

A longer-stroked engine increases the capacity to 749cc and power is said to have been lifted from 94kW at 11,900rpm at the crank on the stock 675R, to a claimed 116kW at 14,200rpm at the wheel on the base Spirits, and 132kW (180hp) at the same revs on the R models.

The chassis in which this engine is housed is common to all four models, and is a specially designed tubular steel trellis frame with the individual tubes brazed together rather than welded, supposedly to give improved feedback to the rider via controlled flex, and for ease of repair after a crash. Fully adjustable K-Tech suspension is fitted front and rear, with twin 320mm front discs and six-piston calipers from PFM, with a 220mm rear disc and two-pot caliper. The steering geometry is fully variable, with both adjustable headstock and triple clamps to vary rake and trail. The twin-sided aluminium swingarm is handmade to MotoGP spec, says Spirit, and has an adjustable pivot point, while the seat subframe and all the bodywork is made from carbon fibre, as are the five-spoke Dymag wheels.

Spirit’s focus on saving weight has resulted in a claimed 140kg weight including oil/water but no fuel in the 15-litre tank for the fully faired GP Sport-R that’s devoid of street equipment. The comparable but unfaired GP Street-R weighs in at a claimed 145kg for. Both the faired GP Sport and Naked GP Street street-legal models have the same claimed wet weight of 150kg fitted with road gear, a notable saving on Triumph’s quoted figure for the street-legal 675R of 167kg.

Prices for these high- tech high end models are inevitably stratospheric, with the GP-Sport and GP-Street priced at £44,999 ($76,500), the GP-Sport R at £64,999 ($111,000) and the GP-Street R at £69,999 ($119,500), all with a seven- year warranty. It’s unclear why the nakedbike should be more costly, but all four variants are available as bespoke motorcycles built to individual spec in any colour you like. Full production will begin early 2017