Crighton CR700W: Ultimate Track Bike

When it was unveiled back in November 2021, the Crighton CR700W was hailed as the ‘Ultimate Track Bike’, designed and made by the creator of the world’s most successful rotary-powered race bikes – Brian Crighton. 

The CR700W encapsulates all Brian’s vision, knowledge and technical successes attained over his 40-year career in developing, tuning and racing rotary-powered bikes. But without legibility to run in any existing racing class, apart from anything with a an open class category, the bike is built as a track day bike, and only 25 will be produced, all hand-built by Brian Crighton at state-of-the-art Rotron Power aero-engine facility in Wiltshire, UK. Price tag for the bike? Prices start from £105,000+VAT.

“In so many ways the CR700W is the culmination of my career’s achievements,” said Brian Crighton. “It encapsulates the absolute best of my engineering wisdom. I believe the result is the ultimate track and racing motorcycle.”

Brian, of course, already created the ultimate in racing machines with his RC588 and RC588W motorcycles dominated British Superbike racing in the late 1980s. By the early 1980s, the once legendary Norton motorcycle marque had lost its lustre, with ownership of the name being fragmented and scattered across continents. The company’s rotary-engined focus was then centred on road-going workaday machines, rather than high performance racers. But soon, in its British birthplace, a team of engineers worked to restore Norton to its rightful place as a maker of world-class road-going motorcycles and, thanks to the determined agenda of one man, also unbeatable racing machines. That man was Brian Crighton. 
Brian was the former three-time British 50cc champion who combined his experience as a racer with his genius as an engine tuner to single-handedly design and develop what would soon become the legendary rotary engine-powered racing Nortons: bikes that were soon to sweep all before them.

In 1984 Brian was a service engineer at Norton and a year later was promoted to R&D. It was there that he realised there was a lot of performance potential in the company’s 588cc air-cooled rotary. Determined to prove his point, he worked in his free time from the caretaker’s shed, defying the management’s belief that any gains were worthwhile. 
Even after increasing power from 85 to 120bhp his employers remained unconvinced, so in 1987 Brian took his prototype to MIRA and clocked 170mph with it. As a result, in a dramatic change of mind, suddenly Norton were going racing. Within a few weeks the new Spondon-framed racer was made ready. In 1987 they scored their first race win on only the bike’s second outing… the potential was immense.

The RC588 and RCW588 were the Norton Works racers from 1988 to 1994, initially in air-cooled and later water-cooled forms. In late 1988 Steve Spray dominated the PowerBike International at Brands Hatch on the racing prototype and sponsorship from John Player Special followed for the 1989 season, with Brian now as Senior Development Engineer.
It was the high-profile and the distinctly black and gold JPS bikes that then stole the public’s hearts. A glamorous rider line up headed by Trevor Nation and Steve Spray saw the Crighton-designed Nortons dominate race after race throughout 1989, culminating in both the 750cc Supercup Championship and the British F1 title. 
Such success brought a change in a management, technical direction and riders, but Brian’s point had been made, and the master was back in 1993 with his Duckhams-liveried Roton machines, having teamed up with Colin Seeley. Once more the Crighton rotary machines dominated the season, this time with the Championship won outright in dominant style. 

It was all too good to be true. So good, that the race regulators then banned the rotary engine from the competition scene, leaving Brian Crighton’s contribution to the Norton marque’s illustrious racing pedigree indelibly recorded in the history books.

Brian Crighton’s faith in the rotary engine design has remained unwavering, leading to the formation of a partnership in 2009 with the sector-leading Rotron Power Ltd (part of Gilo Industries Ltd), designers and manufacturers of outstanding rotary engines for the aerospace industry. 
Crighton worked behind closed doors with Gilo Cardozo, founder and owner of Rotron Power Ltd, and Lead Engineer Shamoon Qurashi, together with the team at Rotron Power to develop the next generation 700cc twin-rotor rotary engine. They have used the latest designs, the most advanced materials and state-of-the-art precision engineering techniques to build the all-new CR700W.

The result is a refinement of the rotary racing motorcycle concept beyond anything previously thought possible. The CR700W optimises all the best aspects of rotary engine technology with highly advanced fine engineering elements of a kind never seen before. And it does so in a reliable robust way, true to Rotron Power’s core aerospace market. As Mason Law made plain during testing of the bike at Silverstone, the CR700W is a crowning achievement of a great visionary’s exceptional career.

The Crighton CR700W will be raced in the EMRA Unlimited class at the Mallory Park Bike Bonanza by Leon Jeacock, the winner of the 2023 Mallory Park Race of the Year – and ridden by former JPS Norton works rider Trevor Nation in the Bonanza Past Masters Parades. 

CR700W TECH FEATURES

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 ENGINE

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 nikasil-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 reservoir 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 supersede that of the industry-leading Crighton CR700W.

CR700W SPECIFICATIONS

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)

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

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      129.5kg