I'm whittling down weight. I keep seeing more places to shave lbs that should've been obvious to me when I was building the thing. The next thing that goes is the aluminum chain case cover that you can see in the photo above. It is getting replaced by a plastic panel that will cover the whole right side of the engine. Should be good for another 3 or 4 lb loss and easier access to the chain/engine.
Polaris RMK 800 snowbike
- Thread starter Brett Kobernik
- Start date
Don't you find you lose a solid edge on sidehills in soft snow by rounding or tapering that edge?
I can understand how it would be better on hardpack but the physics seems all wrong for soft snow. You would certainly never design a ski or snowboard that way.
Last season was the first time I've experimented with a rounded profile on the track. I haven't notice anything significant yet in soft snow. My current philosophy is that I don't trim off enough to make a difference in soft snow. I think length is more of a factor for loosing edge on steep sidehills. I've noticed that the 120s slide out very easy. The 163" on the Unicorn, not so much. That thing HOLDS AN EDGE!! With a full width 15" x 155" track on the Yamalaris, I think I'm covered. Time will tell.
The track is spinning unlike a ski or snowboard.
Agreed ^^^^
I noticed zero washout on my ninja 636 with 156x3.2 rounded to 2” depth on the edges.
I guess that depends on how a person rides , for me it's kind of like going into a corner on a bike . At a slower speed I just have to drive around it but on the throttle the momentum is there and so is the throttle and the drift . Standing in an aggressive mode on a side hill works a lot better for me if I'm sitting I'm not as likely to compensate and react for the washing of the skid that I would also call nimbleness .
Tracks are getting deeper lugged and that takes power and on the flip side that isn't noticed tracks have been manufactured for years with rounded lugs because they help assist , they just aren't as deep . It's all or nothing doesn't make for an all around purpose .
I've mentioned this on one of the builds that seat height has a big factor in this also , my seat height is around that magic number 32 but was not always . The one skid that has 3 shocks up front is more like 34-36 , it trenches and is aggressive as all get out but was also a very bad skid in good snow, was never ment for that. The new Polaris S skid will be the new standard for some . It's lower and the spiel about it being for newbies is either silly or they needed a sales pitch or they don't know what they actually built but say it's the most dirt bike feel. Flatter approach angle and lower center of gravity , is there something wrong with that or are dirt bike riders all arena pros , above my pay grade. The clearance for foot pegs doesn't work for me when triple digits are just a twist away .
While there's been some that have done everything possible rebuilding thiers to accomplish a lower seat height know this to be a better skid. Maybe they are the ones that should get the credit for the S , good job
I think that skid will change the way snowbikers will ride , sitting is no longer for all sleds .
Hardpack is a different way of riding , relying more on the front . The correct ski is actually amazing on hard pack , it also scrubs ponies , so it's like a completely different set up and ski .
Don't get me wrong I'm not being a smart butt and I understand the difference between what I drive and what most of you drive , technology is great , wish I had some of the stuff you guys have access to .
There is a lot of comparison , those that take advantage of it profit .
Took a good look at my buddy’s Alpha the other day and thought “I think I can modify a Polaris skid to mimic that”. Yep, going to try the single rail in a bit.
Does it seem like it's worth doing just for weight savings? I'm not too concerned about tilt. It may only save 2 pounds.
Seems more worth it for a 15” wide track.
Brett, you are doing things that I have laid awake thinking about! Great job and I truly appreciate you taking the time to share!!! So glad I stumbled on this forum.
Good job Brett! Take a look at K Mod, I think they offer a similar setup to replace the alpha rail. Might give some Idea!
On my side I really like the way the monorail feel on my build, but I never tried it with something else. That said, I really think I will go away from the monorail on the next one and use the narrow twin rail setup just like the Yeti kit. I think it is the best of both world, you get a bit of weight saving, shorter shaft are stronger and the track has more room to flex compared to a traditional twin rail. Plus, it is very simple in construction!
On my side I really like the way the monorail feel on my build, but I never tried it with something else. That said, I really think I will go away from the monorail on the next one and use the narrow twin rail setup just like the Yeti kit. I think it is the best of both world, you get a bit of weight saving, shorter shaft are stronger and the track has more room to flex compared to a traditional twin rail. Plus, it is very simple in construction!
Pretty awesome, Brett!! The cool thing I liked about my simple monorail setup, at least the way I did mine, is that when you lean the bike, the bottom of the track stays flat against the ground for full contact, much better contact patch traction, and the single rail leans/pivots inside the track making it feel like a normal bike rolling side to side. The top of the track follows the rail being secured to the rail between bogey wheels, while the bottom stays flat against the ground, so the track is actually twisting in rotation. I couldn't feel any perceived binding but I do want to figure out a real world test to measure how much, if any, power loss the track twisting causes. I'm guessing it's pretty minimal because I didn't notice it with my 13hp Honda motor. Well worth the huge handling benifit and weight reduction IMO. Looking forward to see how you build your monorail setup!
I made mine using only one single runner/hyfax so when I lean the hyfax is actually rolling onto its edge on top of the metal track clips. Didn't seem to present any issues short term, but for long term hyfax lifespan I would like to play around with a slightly curved hyfax, so it has a smooth curved rolling profile underneath rather than a square block profile shape.
Might be slightly lighter and every pound counts but I'm mainly looking at handling capabilities with the 15" track. My current configuration with the 13.5" rounded profile rides great but I'm going to switch back to the 15" track soon. I'm hesitant to cut a rounded profile before trying the single rail.
I’m making slow progress modifying one of my other skids.
I think many of us have thought about this type of stuff. I'm only bummed that I didn't start screwing around with sled engines and clutches 5 years ago!!
Good tip on the K Mod. I found some photos that I'm using for reference. I'm pretty excited that this single rail suspension is going to come together fairly easily. It will be a really good test on the 800 since I already know how the standard skid rides. If it works, I'll convert the Unicorn also.
Your description is basically what I see with my buddies Alpha One. I'm soooooo curious to see how this works!
One of the things to consider is that Arctic Cat had a special track designed to go with the monorail. It has way stiffer support rods running thru it to help control how much the track flexes. If you use a regular track you may find that it will washout to easily on steep sidehills.
they make that track in various sizes from a 146x2.0 up to a 165x3 so I guess if you like the concept, you could buy one to go with your design.
they make that track in various sizes from a 146x2.0 up to a 165x3 so I guess if you like the concept, you could buy one to go with your design.
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