2016 YZ450FX '17 TS ST 120 Gearing

danrix

New member
Lifetime Membership
Premium Member
Nov 10, 2019
4
0
1
Just bought my first 2016 Yammi 450FX with 2017 ST 120. The Bike is complete with thermostat, Hand-warmers, CR Intake, Rad Guards etc..... I've read good and bad reviews on the FX WR tranny and looked through many threads regarding this topic. Does anybody have any experience with gearing whether its front sprocket or Chain case and what has worked best in different snow conditions? It sounds like the 3rd gear is quite higher and not easily held on some hills. Any advice from someone with experience with these bikes in the snow would be greatly appreciated!
 

dooman92

Well-known member
Lifetime Membership
Mar 1, 2010
527
132
43
Danrix, i have a fx with a 120 mototrax kit. My buddy had a fx with yeti 129 kit. Stock the yeti carried third much better than the mototrax. The mototrax had a 2" paddle stock, pos. I put a 2.5 paddle timbersled track on the mototrax and it made a major difference. That's the same track as your kit I believe. With that track, I have a lot more momentum/speed over the 2" that I can now carry third in most situations. Granted, I don't care for the second to third gap but with good traction it is manageable. Unfortunately I did not test any gearing changes. But, fwiw, traction/momentum really helps..
 

danrix

New member
Lifetime Membership
Premium Member
Nov 10, 2019
4
0
1
Dooman, I'll take all the info i can get. Thanks for this. I know I just need to get out and ride the thing and see what I can do with the thing first. Just being impatient waiting for the snow to fly in Northern BC!
 

needpowder

Well-known member
Lifetime Membership
Dec 5, 2007
1,151
304
83
44
Utah
I had a 137 on my fx. Riding elevation 8-11k feet. Awesome bike. Rev second all the way out helps. There were lots of situations where I couldn’t pull third but neither could the bikes i was riding with. Nature of the sport. Bikes just don’t have the power. Doesn’t mean it’s not a blast! I think at your elevation it will be even better. When i rebuilt my top end i went with a high compression Cylinder Works(vertex) single ring top end kit. Made a difference and proved reliable. Cylinder, piston, and gaskets for about 500 US. Well over a hundred hours on that top end when i sold it.
 

danrix

New member
Lifetime Membership
Premium Member
Nov 10, 2019
4
0
1
Nice! Great Info. Bike currently had 38hrs on it. I think at the 100hr mark I may just go with the kits stated above! Either that or go with a BB kit. We'll see what happens over the season.
 
Jan 14, 2004
2,801
1,124
113
A 12t on the engine is going to make the FX granny gear first even more so, which is going to make 1st virtually useless plus they are hard on chains. It will help the 2nd 3rd shift though but at the expense of top end. The conclusion that lots of guys have come to is there is now easy way to gear around a wide ratio trans. Its going to come down to your riding style, terrain type, snow conditions, elevation etc. I rode a wide ratio bike for my first few seasons and thought it was fine until I got a race bike. I'd be inclined to leave it a 13T and try it and see how it works for you, who knows you may love it, don't believe everything you read try it for yourself. Some of the newer 500cc KTMs and Huskys work pretty good with the wide ratio because they have the jam to hold 3rd plus you get a 6 speed which is nice.
 
Feb 23, 2019
11
1
3
Cheney Wa
Than
A 12t on the engine is going to make the FX granny gear first even more so, which is going to make 1st virtually useless plus they are hard on chains. It will help the 2nd 3rd shift though but at the expense of top end. The conclusion that lots of guys have come to is there is now easy way to gear around a wide ratio trans. Its going to come down to your riding style, terrain type, snow conditions, elevation etc. I rode a wide ratio bike for my first few seasons and thought it was fine until I got a race bike. I'd be inclined to leave it a 13T and try it and see how it works for you, who knows you may love it, don't believe everything you read try it for yourself. Some of the newer 500cc KTMs and Huskys work pretty good with the wide ratio because they have the jam to hold 3rd plus you get a 6 speed which is nice.
Thank you.
 

cbc76am

Well-known member
Lifetime Membership
Dec 5, 2016
194
70
28
42
Woodinville WA
the 12T won't work unless you also change the rear sprocket on the 2017 and older kits. it's 12/16 or 13/17 otherwise you can't get the chain adjuster to take out the slack. The gear ratios are very similar but the 13/17 will be tighter and therefore the chain won't rub a groove in the track.

Any gearing changes on the older kits with the lever/wheel tensioner should be made in the chain case not on the bike.
 
Last edited:

CATSLEDMAN1

Well-known member
Premium Member
Nov 27, 2007
2,355
927
113
70
Missoula, Montana
on the older TS kit with my Yamaha wr 450 that was wooped. I found for sure 13t on the bike 17 on the kit, run 16 t top in the chain case and 18t bottom, it will really work well in 3rd most climbing, for sure there is always the too steep, but I ran this for several years experimenting with gearing. Guy that bought kit was on a YZ 450, tried higher gearing in the chain case ( 17/17 ) said he went right back to what I had sold him the 16 / 18. Thats 5-8,000 in western montana.
 
Premium Features