The CR700W combines honed traditional design wisdom with a new powertrain genius. There is nothing showroom-superficial about it, nor is it a mere weekend track day toy. It is Brian Crighton’s hand-built ultimate that realises all new heights of track bike engineering achievement.
The CR700W combines honed traditional design wisdom with a new powertrain genius. There is nothing showroom-superficial about it, nor is it a mere weekend track day toy. It is Brian Crighton’s hand-built ultimate that realises all new heights of track bike engineering achievement.
The CR700W houses one of the most powerful – relative to cubic capacity – normally aspirated engines ever created. It is a precision-balanced, vibration-free unit, low-slung and with a spine-tingling exhaust note. This unique Rotron Power unit helps facilitate the bike’s outstanding handling due to its exceptionally low centre of mass and ultra-light weight, all combining to give a truly unique and unparalleled rider experience.

220hp at 10,500rpm from the CR700W’s fuel injected twin rotor 690cc engine, means 319hp per litre. By comparison, the most powerful normally aspirated Formula 1 engine – the Ferrari’s F2004 – generates 309hp per litre at a frantic 18,500rpm, and the very latest MotoGP bikes deliver around 300hp per litre.

But such power is nothing without control. That’s where 105ft/lbs of peak torque at 9,500rpm comes in: the CR700W’s rotary engine delivers the most tractable and useable power of any motorcycle engine in the world today, bar none.
The 5 defining features of Crighton
The engine’s structural components are cast in high strength LM24 aluminium alloy and are machined in-house. All engine wear surfaces are molybdenum and nicasil-plated to ensure light-weight, low friction and high wear resistance. The main eccentric driveshaft is manufactured from a cryogenically stabilised EN36 steel alloy. The combustion sealing elements include ultra-low friction, two-piece silicone nitride ceramic apex seals. The ultra-low density and extreme hardness of this exotic material provides the engine’s sealing elements with close to zero wear characteristics. Engineering developments such as these, coupled with Brian’s latest developments in super-wide rotor geometry, provide the highest volume-to-surface ratio of any rotary engine ever made. This is to the core of the CR700W’s industry leading performance metrics.
The Gearbox
The gearbox was always the weak part of the rotary racing motorcycle’s legacy. The tremendous power put through the gearbox under racing conditions made the units very hard to make robust. Until now. The CR700W bespoke transmission system incorporates a quick removal cassette, dog-ring, super-finished, gear cluster with increased width for extra durability. This is coupled with a slipper clutch, all designed and made by race winning gear manufacturer, Nova Transmissions Ltd. The primary drive also includes an idler gear which reverses the engine rotation to help hold the front wheel on the track under acceleration and cornering.
The Chassis
The classic Spondon-derived chassis has a single shock rear swing-arm fabricated from 7000 series aluminium alloy, triple section custom extrusions. The head-stock angle and rear swing-arm pivot-points are fully adjustable for individual rider preference and racetrack tuning.

The engine oil resevoir is incorporated into the main spars for extra weight reduction and the front fork triple clamps are available with different offsets to suit rider preference. The chassis is equipped with Dymag carbon fibre wheels, Ohlins or Bitubu front forks and rear shock absorber, and Brembo’s Superbike monobloc spec front and rear calipers.
The Air
Cooling System
Brian Crighton’s racing-winning innovation: the titanium and inconel exhaust ejector system, which utilises the rotaries’ exhaust system to generate a high energy vacuum through the core of the engine. This vacuum accelerates a continuous flow of air through the finned apex of each rotor tip. This unique system is incredibly light weight, requires zero moving parts, extracts zero energy from the engine drive shaft and it is 100% reliable.
The Water
Cooling System
Unlike any other motorcycle engine before it, the CR700W’s engine features an internal cooling channel, spark eroded into the core of the main rotor bearing journals. These channels are then liquid cooled via a fully integrated shaft-driven, inline coolant pump. The intense heat generated at the heart of the engine is rejected efficiently into the cooling system, literally from the inside out.
The Heart of the matter
The CR700W twin-rotor rotary engine contains just three moving parts, measures just 340mm in length, 240mm in diameter and weighs just 24kg. Together with its integrated six-speed gearbox and slipper clutch, the complete engine and transmission unit weighs just 46kg. Each rotor generates 200 degrees of power stroke per revolution and delivers world record-beating stats in all established performance metrics.
It’s questionable as to whether, given the electric revolution, motorcycle internal combustion engine performance will ever supercede that of the industry-leading Crighton CR700W.
  • Engine Type
    Twin rotor fuel injected four-stroke rotary (aluminium block)
  • Engine Displacement
    690cc (total maximum combustion chamber capacity)
  • Max. Power Output
    220hp @ 10,500rpm
  • Max. Torque
    105ft/lbs @ 9,500rpm
  • Fuel Consumption
    0.54 - 0.65lbs/hp/hr
  • Electric Start
    Bespoke high power DC brushless starter motor (option available)
  • Length x Width (fairing) x Height
    2040mm x 470mm x 1151mm  (80.3in x 18.5in x 45.3in)
  • Seat Height
    810mm (32in)
  • Wheelbase
    1440mm adjustable (56.7in)
  • Dry Weight
  • Brakes (Front/Rear)
    Brembo Superbike monobloc spec calipers
  • Tyres (Front/Rear)
    Michelin Superbike spec slicks
  • Suspension Front
    Ohlins or Bitubo Superbike spec
  • Suspensions Rear
    Ohlins or Bitubo special long-stroke unit
Rotron Power Ltd
Unit 9, Chaldicott
Tokes Lane
Rotron Power Ltd
Rotron’s state-of-the-art range of propulsion systems deliver an unparalleled power-to-weight ratio in an ultra compact, zero vibration power pack….advancing a new generation of motive technologies and action sports products for land, sea and air.
Company info
Crighton Motorcycles / Rotron Power Ltd
Registered in England 07120912
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