Burandt clutch/Kurt gear down kit

[Scott]

GOT IT.

The old school gear drive ratio spreadsheet.
You'll need to make your own copy in order to play with the numbers.

Click on "file" and "make a copy" (or download if you're using Excel)..

Play with the numbers and watch the other numbers move.

 

[kanedog]

GOT IT.

The old school gear drive ratio spreadsheet.
You'll need to make your own copy in order to play with the numbers.

Click on "file" and "make a copy" (or download if you're using Excel)..

Play with the numbers and watch the other numbers move.

Venom gear calculator is wicked. Google that chit

 

[Scott]

I'll check it out.

 

[phenix]

Hey Guys great thread here, wish I found it earlier. I ordered Kurts new axsys pulleys only kit for 339. Says a final drive ratio of 2.37 which is accurate but they fail to tell you it’s just the pro ride gears 44/21 (2.095) pulley ratio vs. The 43/22 1.95 ratio. Is it really a big jump? And I wish I just bought used pro ride gears as that’s the exact same stuff.

What do you guys think of putting in a new Q2 set of gears? The top gear stays at 22t but the bottom steps up to 50t (2.27) with the 7 tooth 2.86 drivers final drive of 2.57, maybe that’s too much? Thoughts.

 

[goridedoo]

Hey Guys great thread here, wish I found it earlier. I ordered Kurts new axsys pulleys only kit for 339. Says a final drive ratio of 2.37 which is accurate but they fail to tell you it’s just the pro ride gears 44/21 (2.095) pulley ratio vs. The 43/22 1.95 ratio. Is it really a big jump? And I wish I just bought used pro ride gears as that’s the exact same stuff.

What do you guys think of putting in a new Q2 set of gears? The top gear stays at 22t but the bottom steps up to 50t (2.27) with the 7 tooth 2.86 drivers final drive of 2.57, maybe that’s too much? Thoughts.

It's actually a pretty big jump from 1.95 to 2.09. I think you'll be happy.

I haven't ridden a QD2 sled.

 

[DITCHBANGER]

The best way to figure out gearing is to spend the money on a tki set-up and try various ratios. Lots of opinions on what is to tall and what is to low. Be honest in your estimates on how fast you want to go on a mountain sled, is being geared for 80+mph good? Do you like snappy throttle response and quicker engine rpm recovery? 1.95 to 2.09 is not a big jump imo. Qd2 is a good jump.

 

[Teth-Air]

For those that are a little less familiar it may be good to clarify a couple things. First when guys talk "Pro" gears they usually are referring to the Pro-Ride chassis and not the PRO-RMK because the AXYS is still a PRO-RMK.

Secondly gearing down in small steps is usually good but big steps often requires clutching changes. I have a friend that hated gearing down his AXYS because it allowed the motor to over-rev. Is it fair to blame the gearing? This is why so many guys that have turbos end up gearing up,
they say they want more track speed. Turbo sleds need gearing down more than gearing up as usually low speed conditions suffer due to heavy weights and turbo lag, this is where low gearing helps most. Gearing up to load an engine is a Band-Aid unless you are already at full shift out and still too slow.

 

[grizzslayer]

Teth-Air nailed it! I have a 2016 SKS with BD Sidekick and 163 2.6 with stock drivers. In order to recovery some bottom end, I did 2 things; reduced top gear to 18T; so now a 18/43 or 2.39 CC ratio. Then, I installed TRS clutching to have smoother engagement and lighter primary spring.

Results are amazing; bottom end is great, and clutching is silky smooth to 8550rpm

 

[pepperhouse]

Teth-Air nailed it! I have a 2016 SKS with BD Sidekick and 163 2.6 with stock drivers. In order to recovery some bottom end, I did 2 things; reduced top gear to 18T; so now a 18/43 or 2.39 CC ratio. Then, I installed TRS clutching to have smoother engagement and lighter primary spring.

Results are amazing; bottom end is great, and clutching is silky smooth to 8550rpm

Agreed, did the same thing with my Mtntk boosted Axys.
The TRS kit made a surprising big positive difference.

 

[Betterview]

Teth-Air is correct about needing to gear up with a turbo if you are only geared for 60 mph. That is why gearing with a turbo is so important. The huge extra power needs more weight in the primary to control rpms once on boost, but too much gear with that extra weight in the primary results in too much shift before the turbo can spool up.

Assuming that a sled is properly clutched we need to remember that the weights in the primary need to be light enough to allow the engine to reach and maintain near peak rpm against the load or resistance provided by the secondary. In general taller gearing offers more load at the secondary and requires a decent amount of weight in the primary to overcome that load and allow shift out. Once we have got the clutching dialed in with current gearing we then we look at changing gearing. Gearing down puts a lesser load on the secondary and often requires less weight in the primary to prevent over shift that does not not allow the engine to reach and maintain the required peak rpm.

Yes, lower gears can pull easier than taller gears on an entirely gear drive system, but on a snowmobile we have variable speed clutching that matches load against power delivered, and it becomes easier to confuse our selves.