if your going to go w/ the 27" tires, just an upgraded primary spring is fine but if your going w/ monster 28" tires then a whole clutch kit is required and i recommend dalton. even w/ the clutch kit you still want to use low range when in the bad areas as w/ the extra weight and heavier tires you could smoke your belt in high. just my .02

 

EPI is the only way to go. 20+ years of CVT racing and development experience.

And even with 27's you need more than a primary spring. The primary spring would only change your engagement rpm and possibly the WOT rpm.

 

<div class="FTQUOTE"><begin quote>Originally posted by: jeffls

EPI is the only way to go. 20+ years of CVT racing and development experience.



And even with 27's you need more than a primary spring. The primary spring would only change your engagement rpm and possibly the WOT rpm.</end quote></div>

well since i did some testing on the 800, this is what will work on the 800's w/ the dalton prim. spring is all you will need w/ the 27" tires and this does NOT effect wot rpm's. note: this was on an 06' 800.

 

I probably wouldn't go with the 28" anyhow. Too scared I burned my clutch/belt and eat CV's
I think you Stendori have done pretty good running 27" for a while with no issues, right? I mean
I know you upgraded your primary a little while ago but I do remember 28" posters from previous
threads talking about how they broke axles, CVs and such. And its only a 1" diff from the stockers
anyway, wouldn't think that would be too much harder. Also, would I need spacers for the 27" with
the new 08' 800?

Regards,

R'

 

NO...If you want to then sure...I would base it on the machine and displacement. My 550xp i increased to 28 Zillas , no new clutch and it has plenty of torque in high range. Actually removed/tamed down the snappy, neck snapping take off it used to have so its more comfortable to ride now.
In the chit, yes, use low range. But is it NECESSARY to clutch it ? I vote "NO"

 

It also helps that Zilla are the lightest 6ply Mud tires made .
Maxxis Zilla
For example a 28x10-12 Zilla is 26lbs while a smaller 25x10-12 KENDA EXECUTIONER is the same weight with a shorter 1.06" lug vs the Zilla's 1.19" lug.
Kenda Executioner

I have 26" Zilla's on my stock clutched 350 Grizzly and it runs great and that machine does not even have a low range.

You do not need a clutch kit in low for sure.
28" tires on a 500 sure would not be a selling help to me.