Yz450fx vs wr450

[jz]

I have a '17 FX with a yeti kit. 13 tooth CS(stock) sprocket. I use 5th on trails and firm snow. The way I see it, If you want a heavy flywheel, high out put stator, buy the fx or wr and change to "F" 1-4 gear ratios. Very easy if you split cases before. Or, buy the F and upgrade stator. Neither choice will be "perfect." These are custom built project bikes, and require fiddling to get right.

I can ride with the guys on motorcross models, I just have less than ideal gearing for climbs. Next time I have the cases apart I will change 1-4 gearing.

I ride dirt and snow, not on the same bike. Where I live, 450 four strokes(wr,fx,f) just plain SUCK on technical trails compared to a 300 2 stroke. There is a reason many people just keep the snowbike a snowbike, and ride something else on dirt. I have done it both ways, my last kit was TS MH on a 300 2st. What works on snow will not be a good set-up on dirt.

Good luck with whatever you choose.

 

[thewwkayaker]

I have a '17 FX with a yeti kit. 13 tooth CS(stock) sprocket. I use 5th on trails and firm snow. The way I see it, If you want a heavy flywheel, high out put stator, buy the fx or wr and change to "F" 1-4 gear ratios. Very easy if you split cases before. Or, buy the F and upgrade stator. Neither choice will be "perfect." These are custom built project bikes, and require fiddling to get right.

I can ride with the guys on motorcross models, I just have less than ideal gearing for climbs. Next time I have the cases apart I will change 1-4 gearing.

I ride dirt and snow, not on the same bike. Where I live, 450 four strokes(wr,fx,f) just plain SUCK on technical trails compared to a 300 2 stroke. There is a reason many people just keep the snowbike a snowbike, and ride something else on dirt. I have done it both ways, my last kit was TS MH on a 300 2st. What works on snow will not be a good set-up on dirt.

Good luck with whatever you choose.

Question for you - you say you can ride with the motocross models but have less than ideal gearing for climbs. What happens on the climbs? Just slow or do you get bogged down and fail a climb they can or...? Also have you tried changing the ring and cog (or front and back sprokets)?

 

[needpowder]

I have to ask (I decided to see what would be involved in modifying the gearing with the two rings - front and rear). I think I mathed this correctly and hopefully had the correct transmission ratios when I did this.
Using a 12 tooth front AND a 54 in the rear would make 1st and 2nd pointless but 3rd gear on the fx nearly the same as 2nd on the "f" and 4th gear on the fx nearly the same as 3rd on the "f". Thus the changes I mention give you those two important gears. The first two gears however become very low but other than for loading this isn't important. And I THINK (I didn't check the calc on this) 5th gear would then be similar to 4th gear. So you'd lose the top gear but I can't see much use of that. Basically you'd have 2,3,4 gears similar to a "f" bike for snowbiking.

From what I've read and my little experiences 2&3 are the important gears and 4th on easy roads.

I don't know if you can run a 12 in front and find a 54 for the rear so it might be moot.

Not sure where you ride, if you mentioned, I forgot,. In our high elevation steep and (hopefully) deep terrain I personally use first gear on my F a ton. I also try to shift up from fifth gear hoping there is another very often. Even on my FX first gear was handy and I sure loved fifth! 10-15 degree downhill half mile long meadows with hero snow on top. I wish I had 10 gears!
It sounds like the FX will be a great bike for what you have planned. I wouldn’t even mess with the gears at first. Maybe see what you like and don’t like about it and then do a much more minor change in the chain case.

 

[jz]

Question for you - you say you can ride with the motocross models but have less than ideal gearing for climbs. What happens on the climbs? Just slow or do you get bogged down and fail a climb they can or...? Also have you tried changing the ring and cog (or front and back sprokets)?

The wide ratio gear spacing. In some situations the 2-3 gap is too much for the engine to pull. I am at 10k' asl, with big mountains, so much less power. I end up revving the the snot out of second. In most situations it is fine. Going to a 12 tooth counter shaft would probably be too low. I haven't tried a 14 tooth cs sprocket yet. The answer may lie in the belt pulley gearing. At this point I am ok with my set-up. I will likely leave it as is, and change the transmission gearing next case split. Or buy the appropriate bike, HOWEVER, I added the kick start to the '17(can not do that on newer generations), I added a 3 gallon YZ Acerbis fuel tank(no stupid shroud wings with fuel up high), also unlikely on newer models.

To me, It is all about the compromises you want to live with. I like my FX.

good luck