2021 Drivers and Gearing

[goridedoo]

Any one have info on top and bottom tooth count on the QD2?

6 or 7 tooth drivers with the series 8 track?

Would be nice to be able to compare final drive ratios with current models.

 

[justinkredible56]

I think most of the answers you're looking for are in these videos:

 

[kylant]

so summary of the 2 videos above:

on QD2 sleds:
22 top gear
50 tooth bottom
73 tooth belt (longer)
6 tooth drivers

2.75" track, 3.5 pitch. in both 155 and 165

 

[Snowman.PRO.]

so to upgrade my 16 axys, Looks like I'd need
-new longer belt
-new 50tooth bottom sprocket...

Am I missing something?

 

[kylant]

how does the driver tooth count affect final ratio?

 

[goridedoo]

how does the driver tooth count affect final ratio?

Technically the tooth count doesn't, but rather the overall circumference of the driver/drivers does. A 6 tooth 3.5" pitch results in the same final drive ratio as 7 tooth 3" drivers. 6 x 3.5"= 21" and 7 x 3"=21". Now say you want to compare 8 tooth 2.86" to 7 tooth 3" pitch you would again multiply the teeth by the pitch... 22.88" and 21". The smaller driver provides lower gearing by approximately 8%.

Feel free to correct me if I am wrong. Final drive ratios are confusing for sure.

 

[DITCHBANGER]

Ibackshift.com has a great gearing calc for all driver sizes. Even has the 6 tooth 3.5 pitch on there.

 

[mt.sledder]

That sure looks like an aluminum lower sprocket on the quickdrive.

 

[justinkredible56]

Did y’all notice that even after redesigning the system enough to call it “quick drive 2.0” that they still use that stupid bandaid clamp on the driveshaft? Kinda crazy

 

[DITCHBANGER]

Clamp works..who cares if its there

 

[kylant]

Technically the tooth count doesn't, but rather the overall circumference of the driver/drivers does. A 6 tooth 3.5" pitch results in the same final drive ratio as 7 tooth 3" drivers. 6 x 3.5"= 21" and 7 x 3"=21". Now say you want to compare 8 tooth 2.86" to 7 tooth 3" pitch you would again multiply the teeth by the pitch... 22.88" and 21". The smaller driver provides lower gearing by approximately 8%.

Feel free to correct me if I am wrong. Final drive ratios are confusing for sure.

so what are the final drive ratios?:
7 tooth 2.86 drivers with the axys qd 22/43
6 tooth 3.5 drivers with the new 22/50 gears

 

[goridedoo]

2.47:1

2.23:1

I think ?

 

[MountainCat1]

Aren't desirable final drive ratios for mountain sleds between 2.55 to 2.65 :1 ??

 

[kylant]

2.47:1

2.23:1

I think ?

then that wouldn't be geared down, or am I looking at that wrong??

 

[goridedoo]

then that wouldn't be geared down, or am I looking at that wrong??

Higher the number the lower the gearing.

And for comparison guys gearing down their Axys with Pro RMK gears end up around 2.38:1. So the QD2 is lower yet, which actually surprises me. Those who haven’t ridden a geared down Axys will be amazed at how different the 2021 will feel.

 

[goridedoo]

Aren't desirable final drive ratios for mountain sleds between 2.55 to 2.65 :1 ??

Not necessarily, depends on the sled and I suppose (???) what is used as the “baseline” driver size. Poo guys typically use the 2.86 8 tooth as the “baseline” when calculating final drive ratio.

I would say the desirable ratio for Axys sleds has been 2.3-2.4 the last few years- atleast thats where most guys who have been gearing down end up.

 

[kylant]

Higher the number the lower the gearing.

And for comparison guys gearing down their Axys with Pro RMK gears end up around 2.38:1. So the QD2 is lower yet, which actually surprises me. Those who haven’t ridden a geared down Axys will be amazed at how different the 2021 will feel.

no, i understand that higher number is geared lower. but above, you have lower ratio on top indicating the 7 tooth 2.86 axys is geared lower than the 6 tooth 3.5 new gear ratio.
or did you have numbers reversed:

7 tooth 2.86, 22/43 =??
6 tooth 3.5, 22/50 =??

 

[goridedoo]

no, i understand that higher number is geared lower. but above, you have lower ratio on top indicating the 7 tooth 2.86 axys is geared lower than the 6 tooth 3.5 new gear ratio.
or did you have numbers reversed:

7 tooth 2.86, 22/43 =??
6 tooth 3.5, 22/50 =??

Ah, yeah my bad.

7 tooth 2.86, 22/43 = 2.23:1
6 tooth 3.5, 22/50 = 2.47:1

 

[madmax]

Super happy with the lower ratio qd. I had originally heard they were just using the pro pulleys, but the qd2 is lower than the pro pulleys. That new 2.75 track is going to be amazing. My epic 2.8” track is so much better than the Polaris 2.6, I’ll assume the 2.75 Polaris will be very similar to the epic 2.8”.

 

[damx]

I'm trying to find info on the series 8 tracks, like lug stiffness/ flex compared to the 2.6". Madmax how does the epic do in wet heavy snow? Does it fold over and like the poo2.6" ?