I love it when people talk about how heavy the reciprocating mass is on the WR450 due to its size, when the KTM450XC has the exact same bore and stroke 95 x 63.4mm. Both engines have twin overhead cams and counterbalancers. The KTM probably has a lighter flywheel, but most people end up adding a flywheel weight to it anyway, so that is a mute point. Ditto on the YZ450F.
Think reciprocating mass is making your bike heavier ? Start it up and move it side to side while idling. Then rev it to the redline and do the same thing. Feel the difference ? That is the MOST difference that reciprocating mass could make to the handling of the bike.
Think the 2012 WR450F is a long bike ? Think again... all the KTMs, even the lowly KTM200xc have a longer wheelbase, some by nearly an inch.
Wanna know the real reason the KTMs feel light ? Other than being 18 to 24 pounds lighter, its chassis geometry. 22 mm offset versus 25, steeper steering angle, 27.5 degrees versus 26.3 degrees.
I wonder why Yamaha sits on its a$$ while KTM cleans up in the off road vehicle market ? They seem to have all the parts on the shelf to make an excellent off road racer, both 2 stroke and 4 stroke. C'mon, Yamaha !
As for having a "hard on" for Yamaha, maybe I've sat through too many bitch sessions where KTM riders complained about issues they had with their bikes. Coolant leaks from beneath the power valve on their 2 strokes, suspension that flat out didn't work, fork seals, etc. Personally, I wouldn't be buying a bike with a 100 hour recommended overhaul interval and then trying to figure out how to stack power boxes to get the powerband you want. I'd rather buy a bike with an overbuilt/understressed engine and figure out how to make it handle.
Yamaha bikes have excellent engines, frames and suspension. The WRs are heavy, but that can be dealt with. The YZs and YZFs are excellent all round bikes.
I think the whole light and flickable bike movement is over rated. The KTM200XC rider couldn't make it up a big hill on our last ride. Now way, no how. Had to take a long traverse and then pick his way through a rock garden and then a bunch of trees to join up with the group. How tiring and enjoyable was that ?
The vet expert bored and stroked YZ125F rider was so tired after another ride he couldn't stay awake on the ride home. Commented that he needed a bigger bike to keep up with the 300cc 2 stroke riders. He spent his day constantly shifting and trying to keep his engine in the powerband.
Every 250F rider I know has either talked and wished about engine modifications or is running a ported head and/or big bore kit, to various degrees of success. Furthermore, all the Japanese woods 250Fs (Yamaha and Honda) are heavy pigs, so most of the 250Fs being used in the woods are motocrossers, suffering from the wrong gear box and suspension.
I think the top woods bikes candidates are the YZ450F, YZ250 and WR450F. All of these will require a bit of work in various areas. At least the Yamaha motocrossers in this list can use WR gearsets in their transmissions. This isn't an option with other manufacturers. For me its easier to remove weight from a WR than to mess around splitting YZ cases to install WR gearing.
If I was going to go for a lighter, more flickable bike, it would probably be a 2014 YZ250F.
Edited by MidlifeCrisisGuy, August 16, 2014 - 04:05 PM.