Another aspect of a high pulley ratio from shim(s), machining or a narrow belt I haven't read in this thread is there is less strain put on the wet-clutch assembly at take-off near the engine engagement r.p.m. of the wet-clutch shoe springs.
This happens because torque is the engine power used to get a load moving (whether coming out of the hole hard during normal riding or pulling a heavy load as pictured above) and the higher ratio from c.v.t. mods. lets the engine r.p.m. increase more over the stock pulley ratio. This increase in engine r.p.m. at take-off from zero ground speed provides greater lock-up pressure sooner in the wet-clutch drum to reduce slipping between the shoes and the drum.
Does everyone need this? No.....or not in most daily riding situations but.....in the game of changing the pulley ratio just in case of need I learned I can work the system much harder when needed with great results.
To take this game of c.v.t. mods to the next level after shim/machining mods I learned the stock 660 secondary spring rate was less than needed so....after a few different springs I learned the E.P.I. purple spring was the best choice because I didn't want more spring rate which puts other parts in the drive-line at risk.
With the purple spring there is no slip during 99% of my time on the trail(s), but every now and then I can get the bike bound up and with to much throttle the belt can be heard lightly chirping inside the cover. It is in one of these situations I get out the winch cable to ride on. I feel if I had a heavier spring I might break an axle, then be stuck with a bigger problem.
Also I want to point out your best set-up depends greatly on the tire diameter you run. I feel the 26.5" tall true size is best for the Grizzlies c.v.t. system so take this as a guide only. This is based on my trail conditions which are not like some other members around the world.
As for expense, those of us that enjoy the higher ratios already know the expense
so know when we recommend a mod the recommendation(s) comes from our riding experiences. These experiences may be varied, so for me the benefits are an easier machine to handle when out on the trail.
Around here a day ride can be well over a hundred miles which is a long way past the range of a stock machine's fuel capacity. In the stock configuration, to go this distance or more in a day with no access to a town (gas pump), the addition of an extra fuel tank is needed which then changes the balance of the machine. C.V.T. mods can greatly increase the range of a Grizzly on one tank of gas which I like.
A few years ago 3 other members of G.C. met me in my local area for a few days of riding. The first to arrive was here for a Y.O.L.O. trip and we had spent the previous 9 months planning for his arrival and spent his first two days here getting him use to the area trails and double checking his 700 c.v.t. set-up for our third long day out on the trails. Our goal that day was ride two Grizzlies 500 miles each without using a gas pump or fuel dump placed earlier. We had to carry everything we needed for the day from camp. We did 455 miles that day while relying on c.v.t. mods to raise the fuel range of a tank of gas by lowering the cruising engine r.p.m.
Then while gone that long day, the two others members met us in camp for 4 more spectacular days on the local trails, and over 7 days the first member to arrive and I had done 978 miles.
Having a well behaving machine was nice, so at the end of each day we could get ready for the next day out.
C.V.T. mods are not needed by all so let me point out to new members while going back through old threads, look for how many members remove c.v.t. and what those mods are and the reason for removal.