OK, so there’s a possibility that by the time you read this, Triumph would have broken the world land-speed record for motorcycles. Or not! Earlier in August, the Triumph Infor Rocket Streamliner became the fastest Triumph motorcycle in history by blasting across the Bonneville Salt Flats at a speed of 274.2mph (441.28 kph). But unfavourable conditions delayed the run to break 376.363mph (605.69 kph) – the speed record held by the Top 1 Ack Attack Streamliner since 2010. Triumph’s pilot for this mad run, Isle of Man racing legend Guy Martin, had a crash during his FIM-required certification run. Thankfully, Martin came out unscathed, but the Rocket Streamliner is in for a full check-up before it can run again. So, its a good time to take a look at just what makes this incredible machine tick.
The biggest challenge of attempting ridiculous speeds like 400mph (643.7kph) is to overcome air resistance, which increases exponentially as the speedometer climbs. At the Streamliner’s top speed, it’s almost like driving through a thick soup. After multiple simulations and wind-tunnel testing of a number of body shapes, the 24th iteration of the design was finalised. The goal here is to go in a straight line, so turning isn’t a concern. But make the bike too stable and it runs the risk of falling over with even slight crosswinds. And unlike most of the streamliners that came before it (including the Ack Attack), this Rocket doesn’t use fibreglass on steel tube construction, instead opting for a carbon-Kevlar monocoque that won’t deform in a crash.
As speed goes up, suspension softens. So, to avoid any changes in aerodynamic characteristics due to the suspension moving up or down at high speeds, the Rocket runs an extremely stiff aluminium suspension setup with Öhlins TTX36 dampers at both ends designed to weigh up the wheels. The stiff tyres, with their thin rubber and big nylon structure holding them together, have been created for the sole purpose of doing 400mph (643.73kph) by Goodyear. But they’re fairly old-tech, designed almost 15 years ago and actually use bead-locks to keep them inflated on the rim.
A mighty heart
Powering this beast of a machine are two separate Rocket III motors customised by Carpenter Racing. While the stock motors are 2.3 litres each, these run a reduced stroke for a combined cubic capacity of 2,970cc. With a couple of Garrett ball-bearing turbochargers thrown in for good measure, this methanol-powered monster can make a whopping 1000hp at 9,000rpm. The two engines each have their own gearbox, and the two output shafts from them are linked together through a
Going the distance
The record-breaking run takes place over an 11-mile (17.7km) course made up of an absolutely flat, arrow-straight surface consisting of a thin layer of salt with soil below. The salt is quite deceptive; it might appear dry on the surface, but could have wet ground underneath, making acceleration a very slippery affair. So the first five miles (8km) are used to accelerate the streamliner to top speed. Between mile marker 5 (8.046km) and 6 (9.656km) is where the speed is recorded and mile 6 to 11 is used to slow down. When Triumph does attempt the final run, here is where Guy Martin will first coast till about mile 7 (11.26km), deploy the two drogue chutes in succession and use the carbon-ceramic brakes to bring the Streamliner to a halt. But the run will only count if the team is able to turn the bike around and repeat in the opposite direction within one hour. The average of the two runs is taken as the final top speed. But I guess we’ll have to wait a little longer to find out if the Triumph Infor Rocket Streamliner is going to become the fastest motorcycle in the world.
Top 1 Ack Attack streamliner
The current world land-speed record for motorcycles is held by the Top 1 Ack Attack Streamliner. Constructed from chromoly tubing and powered by two turbocharged 1,299cc Suzuki Hayabusa engines, the Ack Attack also makes almost 1,000hp. On September 25, 2010, at the Bonneville Speedway, with Rocky Robinson at the helm, the Ack Attack managed a recorded run of 376.363mph (605.697kph). And in response to Triumph trying to best them, the Ack Attack team is back at it to try and defend their honour from the British usurpers.