After taking on an extensive revamp in 2014, which including major updates to the chassis and motor, the Yamaha YZ450F returns with minor—but very effective—changes for the 2015 model year. Our first ride on the new YZ450F left our test riders surprisingly impressed.

On paper, Yamaha didn’t do a whole lot to the YZ’s powertrain, leaving us to believe that we wouldn’t notice much of a difference between the 2014 YZ and the ’15 on the track. Wrong. We felt a big difference the first time we clicked through the YZ’s five-speed transmission. New fuel injection calibration and ignition timing, as well as a seemingly minor external gearing change, does wonders for the YZ’s DOHC, four-valve motor and power delivery. We rode the 2015 YZ450F back to back with the 2014 YZ450F and found that the ‘15’s motor is far easier to control and manage than before, especially in the first half of the powerband. Richer fueling, combined with a one-tooth smaller (48T to 49T) rear sprocket, gives the 2015 YZ450F smoother and less explosive acceleration off the bottom, which our testers said made the new YZ much easier to ride overall. One of our testers said that, in comparison, the 2014 YZ450F has noticeably more hit off the bottom than the ’15 but that this did not offer a real advantage over the ’15 because it would just wear him out much quicker, whereas he said he could ride the new YZ450F just as hard and fast but without getting fatigued nearly as quickly. Simply put: He, as well as our other tester, easily preferred riding the new YZ450F to the ’14. Our testers also felt that the 2015 YZ has more over-rev than the previous YZ, which they said was a big improvement, as well.

  2015 Yamaha YZ450F

Little things like the YZ’s lighter throttle pull also makes a big difference with the new YZ450F. This is a gripe we have with the previous YZ450Fs—their heavy feeling throttle. Yamaha claims that a lighter throttle return spring reduces pull by 20 percent. That feels about right to us.

  2015 Yamaha YZ450F

The YZ450F is the only bike of the big-bore four-stroke motocrossers from Japan that isn’t being offered with air forks in 2015, which is the latest trend in motocross right now. The YZ instead continues to rely on its well-liked KYB Speed Sensitive System (SSS) spring fork, but we are not going to knock the bike for that, at least not yet. Air or not, the Yamaha’s fork is very good; in fact, it has been regarded by many as the best of all the previous production spring forks, so Yamaha isn’t in any hurry to jump on the air-fork bandwagon. And we’re definitely okay with that, but who knows for how long? We should know after we get a chance to spend more time living with the new-generation TAC air forks now found on the KX450F, CRF450R and RM-Z450s. Right out of the crate, our testers feel that the ‘15’s fork comes setup a little on the stiff side, and both riders went searching for something a little plusher via the fork’s compression damping adjustment. Once it was found, they are again very happy with the YZ’s fork. As always, the SSS fork offers a wide range of adjustability. Our two test riders differ of about 30 pounds but both of them had no problem finding a setting they were more than satisfied with, and same goes for the YZ’s rear suspension.  

  2015 Yamaha YZ450F

A year after getting a major overhaul to the YZ450F’s aluminum Bilateral Beam chassis, the 2015’s chassis was pretty much left alone, though Yamaha redesigned the lower engine mount. It has a new shape and is made out of steel instead of aluminum, which Yamaha claims results in an improved front-tire contact feel, more so while entering the corners than anywhere else on the track. All we know is that the new YZ450F is indeed a very good turning motorcycle, especially since getting its big chassis update last year (2014). As one of our testers put it, “it just goes everywhere you point it without complaint.”

The 2015 YZ now comes fitted with Dunlop’s new MX52F (front) and MX52 tires, which we have found to work very well on a wide range of surfaces. We feel this is a big upgrade over the previous YZ450F, which is fitted with MX51s. The YZ450F again comes with new wear-proof in-mold graphics, and now has black-colored Excel rims and a gold D.I.D. chain with corrosion resistant plating. Another nice plus this year is that the air filter box is now attached via Dzus fasteners for tool-less entry. Overall, we are again impressed with the YZ450F. The new year sees the YZ450F getting a more controllable and less fatiguing (to the rider) motor and sturdier suspension. This comes on top of what the YZ450F already has: a solid chassis, excellent suspension, comfortable ergos and excellent turn capabilities. Tack on four-position offset handlebars mounts with generous 36mm adjustment, tapered aluminum handlebars, fully adjustable suspension, adjustable ignition/fueling mapping (via Yamaha’s available GYTR Power Tuner) and a choice of colors (Team Yamaha Blue/White and White/Red) and you have a bike well worth considering as your next new ride at the races. And, at $8590 (which is up $100 over last year’s), it is still the least expensive bike it its class, so far (Honda has not yet announced an MSRP for its 2015 CRF450R; the ‘14 sold for $8699). And don’t forget about Yamaha’s extensive contingency program.

  2015 Yamaha YZ450F

 

 

Photography by Kit Palmer

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