250 MOTOCROSS BIKES ON THE DYNO: THE WRAP

MotoFactory · 14 декабря, 2024

The 2025 Dirt Bike 250 MX shootout is done. We had to take our time with this one. First of all, it was eight bikes deep, which is hard enough. Making it harder yet was the fact that four of them had significant changes (the GasGas, Honda, KTM and Husqvarna), one was a complete redesign (the Kawasaki) and one was a brand-new bike (the Triumph). In the 54-year history of Dirt Bike, only one shootout was larger; our 2022 450 shootout with 12 bikes. Even that one was easier than this. Almost all the 450s were unchanged that year.
The last thing on the agenda for this year’s 250 shootout was to take them to the Pro Circuit dyno. We always write the test and produce the video before we see the dyno numbers. It keeps our test riders honest. Happily, everything we said in the test jived perfectly with the numbers.

Some people insist that dynos lie. Not so. When a dyno is operated by someone who knows what he’s doing, it always tells the truth–as long as you ask the right question. It can tell you how much power a motor produces, how wide the powerband is, how high it revs and stuff like that. It can’t tell you anything about throttle response, jetting or how much power reaches the track. There are some tuners like Jamie at Twisted Development who have the tooling and the know-how to measure partial throttle output, but that’s a very painstaking, technical process. What we’ve done is provide full-throttle runs, which tells you only what a bike produces in optimal conditions. We rely on track testing for everything else. In this comparison, we printed the run that produced the most peak power. For bikes with multiple maps, we tried them all.

Here are the numbers:

Husqvarna FC250
Max Power = 45.21 at 13,330 rpm
Max Torque = 21.03 at 9,230 rpm

KTM 250SX-F
Max Power = 45.06 at 13,470 rpm
Max Torque = 21.05 at 9,210 rpm

GasGas MC250F
Max Power = 44.81 at 13,160 rpm
Max Torque = 21.45 at 9,280 rpm

Kawasaki KX250
Max Power 43.49 at 12,470 rpm
Max Torque = 20.72 at 9,240 rpm

Triumph TF250X
Max Power = 42.94 at 13,340 rpm
Max Torque = 20.36 at 9,160 rpm

Yamaha YZ250F
Max Power 41.62 at 12,880 rpm
Max Torque 19.49 at 10,100 rpm

Honda CRF250R
Max Power 41.51 at 12,010 rpm
Max Torque 19.92 at 9,530 rpm

Suzuki RM-Z250
Max Power 40.04 at 11,830 rpm
Max Torque = 20.05 at 9,190 rpm

Are there any lessons here? Sure. First and foremost, the bikes with the KTM motors are fast. They feel fast on the track and they look fast on the dyno. The aggressive and mild maps on the Husky and KTM made no difference as far as peak numbers go. Like I said, partial throttle output doesn’t show up on the dyno. Nowhere is that more clear than on the Yamaha. The bike has excellent throttle response on the track, but it isn’t reflected in the numbers.
The opposite is true of the Kawasaki. It looks great on paper, but on the track it’s hard to ride and feels like it has little low-end power.
The Suzuki surprised us because it gained from the last time we had it on the dyno a few years back. The only difference was the Pro Circuit exhaust that comes with the RM Army incentive package.

So which bike wins? If you don’t want to wait for the February print edition of Dirt Bike, you can check out the video below.

ARVE Error:

ARVE Error: Mode: lazyload not available (ARVE Pro not active?), switching to normal mode

Mode: lazyload not available (ARVE Pro not active?), switching to normal mode
src mismatch

provider:    youtube
url:         https://youtu.be/PmYFiXfKw_M?si=_0iCllbJetvXKcYv

src:         https://www.youtube.com/embed/PmYFiXfKw_M?wmode=transparent&rel=0&feature=oembed&enablejsapi=1&origin=https://dirtbikemagazine.com
src mod:     https://www.youtube.com/embed/PmYFiXfKw_M?wmode=transparent&rel=0
src gen:     https://www.youtube.com/embed/PmYFiXfKw_M

ARVE

See you next time!