CVT selection

[darwinpayne2000]

Yeah, I think lack of reverse = deal killer.

My buggy doesn't have reverse, but I try to keep it as light as possible because I end up pushing that son-of-a-gun every so often to get out of a tight jam. Reverse would be nice, but then you end up in JagerDanger's situation. No easy solution.

[JagerDanger]

Is there an advantage of using an OEM reduction gearcase vs making up a chain reduction with a jackshaft? Its probably cheaper to get some pillow blocks, sections of jackshaft and some chain and sprockets than trying to source a used gearbox. The only downside I see is lack of reverse with the chain + sprocket setup.

Just the benefit of reverse and/or extra gear reduction and not having a fixed ratio. Plans for the ST2-NG (what I have) does call for a jackshaft setup. Top part of the jackshaft calls for like an extra inch of shaft to be exposed to run the driven pulley off of it. It calls for 1" keyed shafts with pillow block bearings. Though I'd probably go flangette instead of dealing with pillow blocks. Could do reverse with a starter, flywheel, and the jackshaft for some extra reduction

[Jerm]

if you do a stacked jackshaft setup then you're basically doing the same as what a snowmobile does with a chaincase. Using pillow blocks and such are still needed, but if you mount the chaincase the jackshaft, the secondary CVT mounts to the chaincase, it takes care of the gear reduction down to the lower jackshaft. Its so much easier than setting up a starter, flywheel and all that. Reverse has always been debated on this forum and I've always wondered why sled chaincases weren't used more often, so simple and way cheaper than other gearboxes.
This video shows how they work, decent Canadian accent on this guy too. So many more videos on youtube on this same topic.

[JagerDanger]

I think the reasons they are not commonly used is availability and they might not hold up to the power some are looking for. And they do not work well with motorcycle engines. I guess I'll have to ponder this further. I'm already planning on modifying the buggy a bit for better shock choices and a bit more travel. The video was pretty helpful.

[JagerDanger]

Do you have any sled recommendations to look for with the desirable chaincase with mechanical reverse to look for? And are there any years to avoid that are problematic? I want to stay new enough where replacement parts are available but old enough where I'm not spending a fortune. Partly why I can't get an RPM low HP gearbox, $3K is well over budget for just one component.

[Jerm]

I wish I knew which sleds had the best chaincase, it seems to be something useful for this site for sure. The chaincase I used is integrated into the side bulkheads of the phazer, so unless you use that whole setup it won't be good to you.
There are some sleds with big power, 1000cc etc, so I wouldn't worry about the chaincase not handling the power you put thru it. Just remember that not all sleds came with reverse, so you'd have to research which has reverse then go from there.

[darwinpayne2000]

I bought a Polaris 500 Classic snowmobile. It came with reverse and I pulled out the engine and the chaincase to use for my (former) two-seater build. I thought it was a good setup. The upper shaft of the chaincase is a 1" keyed shaft. I also purchased a #50 hex sprocket to go on the lower shaft to drive the rear differential. As stated earlier, the chaincase was basically 2:1 ratio and I was striving for an 8:1 final drive (not counting the overdrive in the clutches.) I went with Polaris because I was already familiar with their ATV's and the P-85 driver clutch and the snowmobile driven clutch are basically the same, just larger, than the ATV clutches.

There's no shortage of people that think that Arctic Cat is the cat's meow and Yamaha also has a large fanbase. I thought the 1" shafts on the Polaris chaincase would give me flexibility.

[JagerDanger]

If it was a Polaris or Yamaha, I would have bought it long as it was in my price range. I'm not overly bias with brands, this is just my first sled I've owned myself. My dad bought us a 1985 Polaris Indy 500 (Fuji 488) back in 1996 from a neighbor and family friend. I probably jumped on this too fast. But I'll look for a classic chaincase to see what I can find. I'm not familiar with the old Arctic Cat hex clutches I've seen a couple videos on them. But I may just remove that and go with a Polaris setup since it should fit.

[JagerDanger]

Think I figured out a CVT setup for the meantime until I can get a hold of another sled with the reverse chaincase setup with reverse and just do a complete engine swap, hopefully it'll have electric start as well and a much higher Stator output.

[JagerDanger]

I'll be heading up to Minnesota again at the end of the month, so I'll have time to work on the sled. If I can't get it running, I'm not sure what I should get for an alternative engine. I'll be honest, I hate wiring and I hate fuel injection for the sole reason that they suck to get going right if you don't place a sensor just right. But I'd need something that is budget friendly, decent power, and has a ton of aftermarket support and options in case OE parts are hard to get or not available anymore.