This spring we dropped and rolled a driveshaft on a Matryx RMK. Results were incredible. We were able to use 7T 3.5 pitch drivers with a 3.25 Series 9 track while providing an inch of clearance between the front cooler and the ends of the paddles. Stock configuration with 6T drivers and a series 9 is less than a half inch. We modified the stock side structure and made a billet piece for the clutch side support to accomplish the drop and roll. We wanted to make this amazing project even better by producing an entire side structure out of billet, incorporating the drop and roll. Also, a guard to protect the belt and gear was machined. The side structure starts off out of billet piece of 6061 at 62 pounds and finishes at less than 5 pounds. I'd say we're having fun in the shop this summer!
Matryx Chassis Drop and Roll
- Thread starter xring60
- Start date
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Looks like a TKI upper sprocket
Must be TKI gearing - there's already no room between the stock bottom gear and the belly pan. Or maybe the guard addresses that? But with the guard, stock gearing would be a bitch to service.
Cool project! I'd buy the billet bearing flange if it was made for the stock position - I'm always smacking mine on rocks. Maybe both sides, if they were for the stock position. I don't think I want to move anything closer to the rocks, but maybe with the added billet strength it wouldn't be an issue.
Cool project! I'd buy the billet bearing flange if it was made for the stock position - I'm always smacking mine on rocks. Maybe both sides, if they were for the stock position. I don't think I want to move anything closer to the rocks, but maybe with the added billet strength it wouldn't be an issue.
Thanks guys. It has been a fun project. I hope to get these up on our website soon.
Yes, that is a TKI upper gear. We plan on using TKI's belt drive parts with the drop and roll. With the stock side structure and TKI's parts (800mm belt) a 58/24 combo is do-able. Unfortunately, this gearing is a bit tall with larger drivers. To accommodate a larger bottom pulley (63t) a longer belt is required. The next size belt is a 896mm. To adjust the belt with 63/24 gearing a longer arm (more throw) is required. The billet version has mounting holes to move the TKI parts to allow adjustment. I'll make a different mount for those wanting to use 63/24 gearing with the stock side structure.
Andy
Avid Products
Yes, that is a TKI upper gear. We plan on using TKI's belt drive parts with the drop and roll. With the stock side structure and TKI's parts (800mm belt) a 58/24 combo is do-able. Unfortunately, this gearing is a bit tall with larger drivers. To accommodate a larger bottom pulley (63t) a longer belt is required. The next size belt is a 896mm. To adjust the belt with 63/24 gearing a longer arm (more throw) is required. The billet version has mounting holes to move the TKI parts to allow adjustment. I'll make a different mount for those wanting to use 63/24 gearing with the stock side structure.
Andy
Avid Products
![IMG_9428[1].jpg](https://www.snowest.com/forum/data/attachments/368/368164-d4ea55a128bfb622d7348118894e3b90.jpg?hash=1OpVoSi_ti "IMG_9428[1].jpg")
That's drool-worthy work! Bigger drivers for less rolling resistance, more bulkhead clearance (even with the drivers), better approach angle - things we all want. Looks very well thought out, and should be a tremendous upgrade. Cooler stuff to me than anything Polaris has come out with the last couple years (and that's ignoring the recalls 
).
).Like many of you, I was thrilled when Polaris came out with the Series 9 3.25” track. From time to time, we need the extra traction a big paddle provides with the dry powder we have in Montana.
I installed it in my 2022 Matryx. I was disappointed that there was only about .375” clearance from the paddle tips to the front cooler.
Polaris’ recommendation for track tension is to hang a 10-pound weight from the track and adjust the tension so that you have .5” to .625” sag. I’ve long considered this to be too tight. Rolling resistance can be reduced a lot by adjusting the track tension so that the tops of the rubber drive lugs are even with the bottom of the hyfax. No additional weight is used in this case, only the weight of the track itself. One can run a track looser than this, but there isn’t a decrease in rolling resistance so there isn’t any reason to do so.
As I was setting up my sled, it became increasingly clear that the track would be hitting the front cooler under acceleration. The centrifugal force on the track going around the 6 tooth drivers at 40mph is 30 lbs. If you set the track tension to Polaris’ spec, you know that there is at least .5” of looseness in the system. That is with 10 pounds of force. Certainly, there will be times that the track comes off the drivers at least .5” with 30 pounds of centrifugal force acting on it. Remember, there is only .375” clearance at rest with this set up.
I rode my sled this way for the winter of 2023-24. Last spring I started working on a drop and roll. My sleds now have all the clearance that they need even with 7 tooth 3.5” pitch drivers which are over an inch larger in diameter. I can adjust the track tension to my liking and not worry about the track rubbing on the front cooler.
We will be making a limited run on the parts needed for you to drop and roll your own sled. If you have questions, or would like to order, give us a call.
Andy
4062614618
I installed it in my 2022 Matryx. I was disappointed that there was only about .375” clearance from the paddle tips to the front cooler.
Polaris’ recommendation for track tension is to hang a 10-pound weight from the track and adjust the tension so that you have .5” to .625” sag. I’ve long considered this to be too tight. Rolling resistance can be reduced a lot by adjusting the track tension so that the tops of the rubber drive lugs are even with the bottom of the hyfax. No additional weight is used in this case, only the weight of the track itself. One can run a track looser than this, but there isn’t a decrease in rolling resistance so there isn’t any reason to do so.
As I was setting up my sled, it became increasingly clear that the track would be hitting the front cooler under acceleration. The centrifugal force on the track going around the 6 tooth drivers at 40mph is 30 lbs. If you set the track tension to Polaris’ spec, you know that there is at least .5” of looseness in the system. That is with 10 pounds of force. Certainly, there will be times that the track comes off the drivers at least .5” with 30 pounds of centrifugal force acting on it. Remember, there is only .375” clearance at rest with this set up.
I rode my sled this way for the winter of 2023-24. Last spring I started working on a drop and roll. My sleds now have all the clearance that they need even with 7 tooth 3.5” pitch drivers which are over an inch larger in diameter. I can adjust the track tension to my liking and not worry about the track rubbing on the front cooler.
We will be making a limited run on the parts needed for you to drop and roll your own sled. If you have questions, or would like to order, give us a call.
Andy
4062614618
So did you see gains with the drop and roll?
Do some side by side runs against a comparable sled?
Unfortunately we ran out of good "comparison" snow by the time I was able to finish this project. One thing that is so amazing is how much less effort is required to turn the track. I'll try to get some numbers and videos up this weekend.
