2018 Yamaha YZ450F

Introduction

DBT's full video review of the 2018 Yamaha YZ450F

It was time for a change and the Yamaha camp did just that with the 2018 Yamaha YZ450F. It still retains a Yamaha feel but it’s definitely not the same YZ450F we’ve been riding the past few seasons. Yamaha did an excellent job evolving the prior YZ450F configuration (reversed cylinder head orientation, rearward slanted intake, forward air filter) and it's still a very popular motorcycle, especially with vets and weekend track riders. And the reason you continue to see a lot of Yamahas at the track also stems from durability. In the past we’ve run Yamadog 450s into the 100-hour mark and beyond with normal maintenance. Now your mileage may vary if you love to test the rev limiter or don’t like to work on bikes (read air filter and oil changes). Overall we have had excellent experiences with our long-term test bikes.

Changes

Thus far it looks as if the 2018 has the same build quality yet nearly every component has been changed or updated. The frame is where the build starts and the new bilateral design comes into play with a 6mm longer steering head, yet the triple clamp offset has also been altered from 25mm to 22mm. The frame is also slimmer with a new cross-member position and upper engine mount. The new frame is stiffer but the flex is not distributed over a longer area, trying to give the rider the best of both worlds.

The plastics are also new, radiators moved forward and the seat is now 8mm lower in the pocket and a whopping 19mm in the rear. The seat is also narrower in the pocket by 18mm. Handlebar height has also been raised by 5mm and moved forward by 6mm. The changes seem to be a lot compared to the older model but most riders quickly felt at home on the new Yamaha.

Although the engine looks very similar, it too has a slew of updates. The cylinder is slightly more upright, new head, cam profile, and bridge box piston. The throttle body has been altered going to Mikuni now. The transmission is stronger for 2018 and there have also been updates to the clutch.

The second biggest change is the addition of a dedicated electric start and gone is any kickstart backup. Yet the biggest news is the innovative engine tuning app for smartphones. This makes having a slew of engine management changes with ignition and fuel ready at your fingertips--providing you pull over long enough to take out your phone. Imagine having 100 different exhaust systems at your ready, this is an industry first and new technology for a production motocross bike. The best part, it’s free when you buy a new YZ450F.

To read more about the updates, here is a link to DBT’s introduction of the 2018 YZ450F.

Power

The YZ450F has never been long in the tooth when it comes to raw performance. In the past few years, KTM and Husqvarna have stepped up the game, especially when it comes to putting the power to the ground. In less than a lap, test riders could feel Yamaha had stepped up its performance, not only with traction to the ground but also over-rev. Each gear can be held a lot longer if desired, or the engine can be shifted into the meat of the power and still works very well. To some, where in the past you had to pick a gear exiting corners before an obstacle, usually second or third, now you can use either in many conditions, rev it or torque it.

The 2018 likes to be ridden hard regardless what gear you are in. If you are a total short-shift rider it’s hard to appreciate how much better this engine works over the older version. Though improved a little, it is just a little. Grabbing larger chunks of throttle gets more power to the ground over the older motor with less wheel-spin, in most conditions. The bottom end is smooth and transitions into the meat of the power is a little higher or smoother into the RPM range than in the past, but there is a little more torque there now.

Less than halfway into the first day of testing we already had our Yamaha Power Tuner Apps blazing away. We discovered very fast that making slight adjustments or using one of the preprogrammed maps actually improved not only the power delivery but also the chassis and rideability for several of our test riders. As the weeks went on, each of our test riders had a map they liked best, and many were very different than stock. Within 20 seconds the YZ could be a whole different-feeling engine. Not that that feature (switching at a track for different riders) is helpful to most. But having maps for a single rider for changing conditions or for different tracks adds a level of tuning reserved for factory teams. You just have to learn how to use it. Or we’ll bet the local tuning genius at the amature race or on the internet forums will help. But it is so easy to get custom, it is worth the time to test and experiment.

The easiest place to start the process is to begin with the preprogrammed (Hard Hitting-Loamy) map. Even with custom maps, several testers often went back to this map as a favorite. The stock map, for some test riders, felt like the power surged or seesawed when you were trying to be steady on the throttle in corners and ruts and upset the chassis in places. The above map actually made a little more bottom, was smoother in the middle allowing the chassis to track in corners better, and it produces a meatier mid range and long-pulling top or over-rev. Then the basic rule of thumb is to treat adding fuel as additional traction (reducing fuel reduces traction) and adding ignition (advance) increases the throttle response, decreasing ignition (retarding) mellows response.

The Yamaha engine is still very race-oriented and fast but can be very smooth and easy to ride at the same time. With the ability to have better torque lower rev and longer pulling on top, the engine is a real bonus for many of our test riders. We had only a few complaints and then with a couple of tuner attempts everyone was super happy.

Clutch action and feel is some of the best we have experienced (except for a strange occurrence, we’ll explain later). We feel we used it less since the power allows more freedom in gear selection but when abusing it doing second gear turns in third, it gave plenty of warning it was getting hot. Shifting was as good as we have experienced in a Yamaha and it liked fresh oil and got better with time. Gear ratios were spot on for most of our riders and even heavier riders who almost mandate a bigger rear sprocket were mostly happy.

Suspension

We guess the old saying, “if it ain’t broke, don’t fix it” truly applies to Yamaha. While others have been scrambling to find the perfect mix with regard to full air-sprung forks or switched back to a spring fork, Yamaha has stuck to their guns with the SSS Kayaba fork. No it’s not the same fork they have been using since 2006 but the basic idea is the same. Internals have been improved and fork outer tube thicknesses and tapers have been altered over the years. The 2018 version has also seen improvements such as larger cylinder pistons, and the shock has a higher capacity reservoir and stiffer shock spring.

It’s been weeks since we first starting testing the 2018 YZ450F and we love the suspension. Part of the feel can be attributed to the new chassis and frame configuration but thus far we are very pleased. And other than spring preload adjustments, which the bike seems to like the 100-102mm range, we often hovered around stock clicker settings other than maybe two-three clicks in either direction depending on the rider. The stock spring rate accommodates most riders up to the 200-lb mark, much over that mark you may have to go up a spring rate. Under 170 and not a really fast rider, lighter springs apply.

Most of the clicker adjustments were to alter or make changes to the chassis more than pure suspension action. The 2018 YZ450F has that mix that we all strive for, that small bump absorption while riding high enough in the stroke while maintaining as little front-to-rear oscillation through larger whoops or when entering corners. Plus, bottoming control that gives confidence when making a mistake when landing short or going long.

The changes have the bike riding a lot more level (chassis helps here too) with less seesaw when accelerating and especially going into turns. The bike jumps well and can handle steep or gradual jump faces without using too much stroke. And when packed into turns, the bike rides high enough to take bumps and low enough to turn and stay stable.

Yamaha has done a great job with the suspension and it seemed to really cater to a wide variety of rider skill levels and weights.

Chassis - Handling

The weight race seems to be on the radar these days and although it can be a factor, we always say, “How light it feels is as important as what the scale actually says.” The scales note the 2018 YZ450F weighs in at 247 pounds but on the track it feels 10-12 pounds lighter. This is a pound lighter than our 2017, if that matters.

Not only does the new Yamaha feel slimmer and very well configured in stock trim, it has a very light feel on the track. Some commented that they could ride longer or do more laps because the new chassis or suspension action caused less fatigue or required less effort to ride at their normal pace. The chassis is very easy to move around on and there were no issues unless you are very short, under 5’9” (those riders wanted a lower handlebar). The new YZ does feel slimmer and part of this is psychological because it also looks slimmer as well. Taller riders really appreciated the taller and further-forward bar position and average riders never had any real issues. Bar position is adjustable.

Like we noted above, suspension action is amazing and we have spent a lot of our testing time on the front end entering corners and into the pocket, or middle of a turn. This is where some riders felt the front end was not planted enough or felt a little twitchy, especially if the ground underneath was not consistent. As we spent more hours on the bike, that feeling was less of an issue but still an area we were always aware of or kept working on with the riders that noticed it. These riders tended to be more point-and-shoot style, getting on the gas later in the turn or waiting a little longer and getting on the gas harder. Riders who carry a lot of speed and follow the front through the turn did not have nearly the issues. Tire pressure and choice could play some role here as well and we intend to test more to really dial this in.

For our test riders, checking or fine-tuning your sag was very important. Also making adjustments to the fork rebound as well. Speeding up the rebound on the fork helped keep the wheel on the ground better. Some even felt that turning in (more) the high-speed compression adjuster in the shock ⅛-turn changed the feel when entering corners and through turns by loading the front tire slightly more by raising the shock ride position.

The chassis is very balanced and that is where it shines. Still, some felt that entering corners and cornering settings need to be improved a little. It’s kind of a conundrum, the suspension action works so well in so many areas that we didn’t want to make any major changes, but some riders had that slight front-end issue in corners. The ’18 does not turn poorly--it is improved a noticeable amount. But for some it can feel a little light at times and not fully planted into turns.

Of note is that on the YZ a rider feels like they are riding “in” the bike as opposed to “on” the bike. Especially when sitting. The higher bars do this a little but it is also due to the shape of the seat and the softness of the seat foam. It helps hold a rider on the front part of the seat and makes it easier to get on the gas harder. But overall, the thinning and ergonomics of the YZ agreed with everyone no matter how small the millimeters were.

Yamaha did not mention making any changes to the front brake for 2018 but we had to note that several riders commented how well the brakes worked and felt they were improved in both feel and power.
Working on the bike is a breeze. No tools for the air filter, just be gentle taking the filter off so no dirt drops through the screen. We’d like to see a skid plate or center case protection standard but getting to the oil drain plug sure is easy. The bike looks awesome and shiny when new but the luster goes away quick. It doesn’t look bad compared to other bikes except when you remember how pretty it was when new. Our chain stretched more than in the past but our rims stayed straighter even after some big hard hits. The blue rims also seemed like they were staying bright but it takes a little more time for this to fade for sure.

And on the strange things list is the fact that on two different times at two different tracks we experienced some strange clutch action. Only to find a rock lodged between the clutch arm on the cases and between the electric starter. These perfectly shaped rocks found their way back there and were difficult to remove without a screwdriver or something to stick in there and flick the rock away.

Even though 95% of the time the bike started right up, we did have another strange issue. Twice we had the battery go into a 10-second shut-off when it was very hot out and the bike did not fire up right away. We are told there is a safety circuit in the battery that can have it shut off under a heavy load. We will try another battery to see if this was an odd case.

Digging deep we wish there was a full protection skid plate but the side protection is nice.

Conclusion

The 2018 YZ450F is a better motorcycle—and that is hopefully expected with a new model. It’s still a Yamaha and they seemed to address the wish list that die-hard Yamaha owners have been asking for. The chassis is slimmer, lighter feeling, and more forgiving. The suspension action, or the combination with the new chassis, has elevated it to the next level. Performance has been boosted with more overall peak power but also improved traction with enhanced rider hand-to-rear-wheel connection. We embrace the electric start and the new smartphone app tuner is an amazing innovation for motocross. A few riders had some front-end turning issues or turning instability (our only complaint, really) but they are not deal breakers because, overall, everyone found so many positives about the new 450F. Some felt the older YZ450F was starting to feel dated against the competition, and this bike proved it. The new YZ should be right there brushing shoulders with the current field with no issues.

And the tuning tool is a game changer that will up the ante for all the manufacturers who cater to riders who like a personalised power delivery.