Drive and ratio differences

[officer farva]

I have a 15 cat with a Tki belt drive. I'm looking to possibly upgrade the sled to a mountain cat chaincase. I see I have 25/63 gearing right now and I see that on the 17 mc belt drive the bottom gear is a 66?? Is the gearing on them different for a reason? They still use 8 tooth drivers just like my 15 right? So why the bottom gear size change?

Also are the drive shafts the same? If I do the swap will I need to get a new driveshaft?

Also what else is needed to convert the suspension? Front arm, front shock, and rails? Am I missing anything else? Is the rear arm different?

I have a 15 with 200 miles and a ton of engine and lightweight parts on it and I can't justify letting it go for pennies cause the used sled prices are brutal these days. So I'm looking to update the important improvements cat has made. I don't mind my old reliable Suzuki 800!

 

[boondocker97]

I just did the MC conversion on my 2014 pro-lite so I understand where you're at with your sled. The lower gear on the MC is two piece with a separate center hub. You have to install the hub first, then the outer part of the gear and bolt them together once they are in there. The driveshaft sits so low that you can't get the solid belt drive sprocket on through the stock cutout in the chassis. I think Tom told me the overall diameter changed to help clear something else, but I don't remember exactly. So to keep the same ratio you have you need new lower sprocket, top sprocket, cover, and the longer belt. I ended up just selling my used belt drive kit and getting a whole new MC kit since I'm running oil delete too. Drive shafts are the same for all intensive purposes. If you get a new MC driveshaft (if it's available) it might save you a little weight.

Rear suspension requires rails, front arm shock, rear shock pull rod, and the part numbers changed for the rear idler arm. Front arm is the same. Get the little mountain cat idler wheel that goes in the center of the front arm too. If you are using non-MC rails you will have to trim rail caps to clear the drivers. I completely swapped my skid for a Kmod, but if I was going to upgrade the skid with stock I'd be watching for someone with a takeoff skid.

 

[officer farva]

Thanks for the reply that makes sense now. I guess I'm gonna have to see if I can sell my tki belt drive setup and then just buy a new setup for the new chaincase from Tom.

what ratio did you go with? I'm assuming you have a 3" track and 8 tooth drivers.

 

[boondocker97]

I'm running 2.54 ratio with 8T drivers, 162 X 2.6 track, 900 big bore, 260lb (street clothes) rider, and 8-10,000 elevation. I'd like to get a 3" under it next year. Tom was doing some kind of deal where he'd just sell you the parts you need or trade some parts in, but I don't know if he's still doing that. Might have to call him and see. Going from the non-MC to MC belt drive the only thing you can re-use is the tank/brackets, tensioner, and the bearings/seals that are already installed.

 

[boondocker97]

Tom set my dad up with 2.64 ratio for his stock '17 MC with the 8T and 162X3 track. His recommendation for 153X3 with 8T is 2.54.

 

[officer farva]

Ok awesome thanks for the info. I talked to him the other day and he offered to trade in some of my parts I have since I just recently bought the kit.

I'm running a 2.53 ratio now with my 2.6 153 and I want to go higher anyways it's a little under geared at the moment. I don't plan on going up to a 3 in cause the majority of my riding is in the trees here in NY and a lot of trail riding to get to our spots. Never enough snow to even need a 3". I only make it once or twice out west for a week long trip in Montana so dropping another 1000 on a track isn't needed at the moment. Already have enough tied up in this damn sled haha.