There's a lot more to testing new motocross bikes than spinning laps at the initial press introduction, and we log countless hours on each test bike throughout the model year to gain a deeper understanding about how they perform. How durable is it? What breaks? What gets better in time? What modifications and/or aftermarket parts have we tried? Those questions and more are directed our way, each and every time we show up at the track.
In contrast to the initial ride day impression videos we create after our first ride on a new machine, this new series – Ten Hours Later – will document the extended time we spend on the machines in our fleet of 2016 test bikes. Though we'll log far more than 10 hours on each bike, that seems like an adequate amount of time to really figure out each machine.
The Yamaha YZ450F swept through our 2015 450 Shootout and won Bike of the Year honors almost unanimously. This year, a few changes were made to the bike’s chassis and man, did they make a difference. Sadly, it was not for the better. Equipped with 22 mm offset triple clamps in 2014 and ’15, they were replaced this year with a set of 25 mm offset clamps, which were paired with stiffer engine mounts and a stiffer shock spring. The result is a bike that doesn’t corner with much precision, or inspire confidence in the front end when entering flat corners. The first thing on our wish list for the Yamaha was a set of 22 mm offset clamps, and we just happened to have a set from our previous test bike in the garage. The Xtrig ROCS clamps bolted right on and immediately restored our YZ450F’s cornering abilities.
The bar mounts of the rOCS clamps may look familiar to KTM riders, and that’s because the same rubber-mounted handlebar system has been available in the KTM accessory catalog for years. We took the opportunity to replace the stock Yamaha bars with a set of Pro Taper Fuzion handlebars in the SX Race bend.
The Pro Taper Fuzion handlebar is unique in that the crossbar can be locked or unlocked, and each setting yields a distinctively different feel on the track. We actually prefer the crossbar locked in ideal conditions, and unlocked in rough conditions.
The Yamaha YZ450F’s airbox is located up above the gas tank and as a result, it gets a ton of air flow. Pro race teams bore holes into the cowling to force even more air inside, but this makes the filter get dirty, quicker. We installed a Funnel Web Air Filter in our bike and were pleased with the results!
The Funnel Web’s unique pyramid surface provides greater surface area and greater airflow. We’ve had the stock air filter – as well as some aftermarket ones – leak dirt on the YZ450F because they become so clogged, but not the Funnel Web.
Don’t get us wrong: the 2016 Yamaha YZ450F is plenty fast and powerful, but we smashed up our stock muffler in a crash, so we got our hot little hands on a FMF Factory 4.1 system for our test bike.
The FMF system actually made our bike easier to control, while at the same time making it more tractable and more powerful. One of the things we like best about it, is that it maintains the stock heat shields, doesn’t stick out further than the stocker, and isn’t obnoxiously loud.
One of the most surprising bolt-ons we’ve tested on the YZ450F is a Rekluse Torq Drive Clutch. Best known for its automatic clutch systems, the tea at Rekluse has enjoyed a ton of success at the highest levels of our sport with the Torq Drive system, which utilizes 12 clutch plates over the standard eight. The result is instant throttle response and more low-end power. We never noticed our stock clutch slipping before, but the Torq Drive makes it pretty clear that there is some slipping going on. We’ve logged nearly 20 hours of abuse on the Torq Drive and it continues to perform flawlessly. One has to assume that 12 plates outlast eight…
Bits and Pieces
- The quick-release fasteners on the airbox cowling come loose while riding and fall out. They cost over $20 to replace! We pull the D-ring off the fastener with pliers and just use a screwdriver to service our air filter now.
- Keep an eye on your air filter beneath the bottommost lip of the airbox. It gets really dirty down there, where you can’t easily see it.
- Use a heat gun or hair dryer when applying the front numberplate graphic – the bottom of the plate has an odd shape that makes it tough to install backing without lasagna wrinkles.
- We’ve kept our engine purring with regular oil and oil filter changes. We rely on Spectro Platinum 4 synthetic oil.