50 years of crackers
This is the result of 50 years of Yamaha motocross development. YZ450FM And in many ways it’s a far purer racer than any Motogp bike
Fifty years ago a Swede called Hakan Andersson entered the 250cc motocross world championship on a prototype Yamaha two-stroke – the first ever YZ. He won the title and the YZ legend was born. Thirty four YZ world titles later and here we are with the most advanced Yamaha motocrosser there’s ever been; Jeremy Seewer’s factory YZ450FM. Obviously, parts of it are ridiculously trick, with a singlecylinder four-stroke motor that’s tuned by Yamaha’s R&D department to precisely match Seewer’s riding style, handmade suspension and plenty of titanium bits. But the frame is almost standard, and the bike’s design follows a rider-centric ethos that’s a far cry from Motogp’s tech-driven mindset.
Never mind aero and shapeshifter devices, the factory Yamaha doesn’t even have sensors on the suspension. ‘We don’t need them,’ Seewer’s crew chief Vitaliy Tonkov tells Bike, ‘we just listen to what
‘The key is understanding what the rider needs…’
the rider says. We do have an electronics guy who changes the [engine] maps for special conditions when we are racing at high altitude, for example, and we change the mapping when a track is very slippery to make the power even smoother, but it’s not like Motogp. It’s more about the rider.’ So no buttons to change maps during races? ‘We sometimes use them during practice if a rider wants to compare two different maps. But in the race the rider has decided what works best and he uses that.’
This attitude even drives engine development, so instead of being a max-bhp monster, the factory single is only slightly more powerful than the stock 60bhp YZ450F you see in showrooms. ‘Jeremy doesn’t look for a lot of power because he’s a light guy [10 stone] and prefers to have very smooth power from the bottom-end and more torque. Our R&D department has known Jeremy for a long time, knows what he wants and makes the engine to suit him.’
It’s the same with suspension. ‘We use factory KYB forks and shock,’ says Vitaliy, ‘which normal riders can’t get, but they’re nothing crazy special – they’re just made to finer tolerances and allow a more exact set-up. The key is understanding what the rider needs and giving it to him – when you do that, you get the results.’