If you go to WK’s website you’ll note the published spec there claims a horrendous power figure of something like 22kW – barely 30bhp. That is the figure for the bike in full homologation mode. Just as with every other enduro bike on the market, these days you need to effectively restrict the bike to get it through the legislators’ tests. WK have to this effect sorted a deal with Yoshimura to supply a competition exhaust for the bike (cost, about £500) to regain full performance (for off-road use only, you understand). With the exhaust in place and with carb rejetted the power figure jumps to a respectable 43bhp and torque’s 42.5Nm (at 6500rpm) as measured on WK’s local (Lincolnshire) dyno.
Unfortunately for us on this test, the rejetting wasn’t entirely successful and the 450RX was prone to spit occasionally on low rev, sometimes cutting out altogether. We had a fiddle with the tickover to overcome this but it seemed to improve during the day probably on account the atmospherics changed dramatically during the course of the day. We’d still say a little more attention was definitely needed here. Given the Yoshi pipe is too loud for green lane riding (although not excessively loud) it could be a quietening insert might just create the right amount of back pressure to sort the carburation.
Notwithstanding, the 450EX started readily off the electric and kick starts (there’s an ignition key, plus speedo and a fair complement of switchgear) and once you cleared that spit-cough off the very bottom it pulled clean and strong. The motor works well and so does the gearbox, the five ratios select clean and precisely. And clutchlessly – which was just as well as the pull at the lever was on the heavy side. Again, this isn’t unusual in this class and can be remedied either by altering the leverage ratio on the actuating arm or fitting an hydraulic unit.
We might as well deal with another negative while we’re about it – the seat foam is too soft. Henry said there was a choice of hard or soft foam and, based on feedback from the public at the NEC, they chose soft. But it’s too soft by a long way – a shame because the shape is just fine. And dare we say again, we couldn’t find comfort with the handlebar set-up. Taller riders will probably want a taller bend, or maybe a riser kit, normal guys will just want a different bend. We shouldn’t be surprised but it’s amazing how much this one detail can affect your response to a bike.
Past that small issue everything improves. The motor is a lovely torque-meister and so the five gears become nice and long and you can really enjoy driving this plot. With the integrity of the frame it can be charged over rutted fields with only the usual wary eye for danger. The brakes worked fine and when it came to cornering it was again good (in fact given the tyres it was doing surprisingly well). The handling is helped, possibly, by the suspension sitting comparatively lower than say on a KTM – we were put in mind of the Beta we tested last issue – and so it was easy to sit comfortably over the bike and push it into the ground, letting the rear spin up a little under power. As said, the suspension felt to be on the soft end of the spectrum but not too soft.
Certainly we were able to subject the test bike to a fairly rigorous day’s testing. From thrashing it along to near top speed on the road, to our man Phil launching it over some fairly hefty jumps, and plenty in between. We ran a thorough day and nothing fell off, nothing broke, nothing stopped working – the internet trolls would be very disappointed.