Best gearing to use

[orky496]

I am looking to do some mods and figure I should start with the gearing as I need to replace the chain and sprockets anyways. What would you recommend for gearing for more speed with out compromising any of the torque / low end? What is stock gearing? What would you recommend for a brand and where is the cheapest place to buy them.

Thanks in advance for the opinions / help

[Duster]

Gearing is always a trade-off to an extent.

If you want more top speed you have to go up on the front sprocket or down on the back.
Which way to go depends on what kind of riding you do.

Stock gearing is 14/38.

Myself, I think the grumbling that goes on is because the internal trans gearing is less than ideal.
1st is too high, all the ratios too close, and 5th ends up too low for the open country guys.
And on top of 1st being high, the rotating mass in the engine is very low/light compared to old school thumpers.
So it stalls down easier, but spins up easier also.


Most guys looking for more speed are just going up to a 15t front to make the gearing 15/38.

Myself, I just use an impact wrench and swap out the front sprockets at will depending on where I'm going to ride that day, or who I'm riding with (slow/fast). It doesn't take me that long to swap it out and adjust the chain slack.

I'm going to try a 15t front next though, because I really don't think it's going to make that much difference in anything except making it faster and making the gears longer. I also have a 39t rear I can use if I think it's too much.


As for brand and place to buy... to be honest with you dude, I'm just getting the Primary Gear brand sprockets from Rocky Mountain ATV.

I've been finding that the same guys who spend the extra money on the fancy sprockets are also the same ones that are breaking them and busting their engine cases.


Myself, I'd just rather have a normal weight, normal hardness, normal material, plain jane set of sprockets that wears about as long as the other parts. I'd rather replace $28 in sprockets here and there than buy new engine cases.

[jeffskfx450]

I run a 14/34. I really like it.

[Duster]

QUOTE (jeffskfx450 @ Jan 3 2010, 10:59 AM)

I run a 14/34. I really like it.

Down 4 in the back is a little faster than up 1 on the front right?
(haven't plugged it in the calculator yet)


Seems like someone played with sprockets a lot and ended up liking a 14t front with a smaller rear best.
But I don't remember who, what size, or what riding he did.


What type of riding do you do... MX, XC, Trail?

[jeffskfx450]

QUOTE (Duster @ Jan 3 2010, 05:16 PM)

Down 4 in the back is a little faster than up 1 on the front right?
(haven't plugged it in the calculator yet)


Seems like someone played with sprockets a lot and ended up liking a 14t front with a smaller rear best.
But I don't remember who, what size, or what riding he did.


What type of riding do you do... MX, XC, Trail?

Yes 4 down in the back would be faster than 1 up front. Stock is 14/38 so going up 1 in the front would be about the same as running a 14/36. I dont like going to the 15 because I don't want to modify the case saver. I mostly run in sand, and sometimes woods, so my 14/34 is a little high for the woods, so I had a rekluse clutch installed, and it really helped. The 34 in the rear really helped the top speed for the dunes.

[Duster]

QUOTE (jeffskfx450 @ Jan 4 2010, 08:42 PM)

Yes 4 down in the back would be faster than 1 up front. Stock is 14/38 so going up 1 in the front would be about the same as running a 14/36. I dont like going to the 15 because I don't want to modify the case saver. I mostly run in sand, and sometimes woods, so my 14/34 is a little high for the woods, so I had a rekluse clutch installed, and it really helped. The 34 in the rear really helped the top speed for the dunes.

Good info.

I think since I seldom see open spaces that I will play around with the sprockets I already have.
I have.... 13t - 14t / 38t - 39t

And I think I'll pick up a 15t to try also (just cheaper than rears).


The great thing though is that I've found another person with a Kawi that has a Rekluse.
I'm debating getting that for several reasons... it's just expensive.

I'm also trying to do my own research on flywheel weights.
Bike guys use them for increased anti-stall and increased traction.
Trying to find one and figure out if it will work on the KFX is the fun part.

[jeffskfx450]

Ebay had some used rekluse clutch kits for the kfx450 yesterday for stating for about $200-250. Yes it does work to keep the bike from stalling, thats why I run it with the taller gears.