Matryx gear ratios

[madmax]

In the "P-22 or P-85" thread there was some discussion on gear ratios. In order to not highjack that thread I thought Id start a gear ratio discussion. Im talking actual QD gear ratio, not final drive ratio. The 3 QD ratios we have available are...
Pro 21/44, 2.09 ratio
Axys (QD1) 22/43, 1.95 ratio
Matryx (QD2) 22/50 2.27 ratio
Ive run the Pro QD gears on all my Axys sleds until the QD2 came out. I personally like the lower gearing of the QD2. Some people are running lower than the QD2. What gears are you running and what you liking about it. In an other thread there was some talk about using the 21 top Pro gear with a QD2 bottom gear (21/50 with 2.38 ratio) using a belt tensioner. Anyone tried that? Or gearing down with a TKI belt drive.

 

[xring60]

For Western Mountain Riding, Primarily NW Montana I liked the performance of a bigger ratio somewhere around 2.40 to 2.5. I know you talked about not introducing final drive but the Polaris QD2 after the 6t 3.5 drivers should be around 2.473. Snappier off the bottom, lower belt temps are advantages of bigger ratio.. For guys that are into big long hills they might tend to prefer a smaller ratio to get more ground speed and momentum to carry them up the hill.

For what it's worth I've been told by gates that anything smaller than a 23 top gear on a 8mm pitch carbon belt destroys gears and belts excessively fast. The Polaris QD stuff is 11mm pitch.

I ran a NA Matryx 850, 24/58 2.416 (tki), 7t 3.5 drivers (overdriven by 7% 2.25 final drive, and a 3.25x155 track, definitely too high geared (lower ratio number), had some belt burn on the bottom sheaves of Primary.

I think VOHK had a sheet but it would be cool if someone made an excel spread sheet with basic ratios and final drive numbers.

 

[madmax]

I didn't want to bring final drive in to the conversation because most people aren't going to change drivers to change the drive ratio and if you wanna run 3.5" pitch tracks you're pretty much stuck with the stock Polaris drives for most people. Avid does offer 5, 6, 7 & 8T, 3.5 pitch drivers for the newer drive shaft, but with the very limited room in the bulkhead with a 3.25 track anything bigger than the 6t will pretty much leave you no room for snow evacuation.

 

[TRS]

Hope this doesn’t side track the thread.
I have always figured my gearing backwards. What I have found that works for me is as follows.
Shoot for 72-74mph on NA sleds, 74-76mph on turbo sleds at a 1:1 ratio and 8250 rpm.
Utilizing your driver size.

 

[madmax]

Not side tracking at all, just looking for constructive discussion for all to understand gearing. Do you ever see 1:1 and 74mph in your mountain sled? The newest Polaris tunes speed limit don’t they with the 3.25 track? I believe in stock configuration, a matryx with QD2 calculates out to about 74mph, that correct?

 

[Sheetmetalfab]

My QD2 boost will hit 85 mph if I’m not careful on the way to the hill.

Lower gearing definitely wouldn’t hurt my track.

 

[madmax]

My QD2 boost will hit 85 mph if I’m not careful on the way to the hill.

Lower gearing definitely wouldn’t hurt my track.

What year boost is it? Does your dash start to flash a warning when you get over 50? My 24’ boost dose.

 

[Sheetmetalfab]

What year boost is it? Does your dash start to flash a warning when you get over 50? My 24’ boost dose.

22

 

[TRS]

22/50 QD2
6 tooth 3.5 pitch driver
8250 RPM
1:1 ratio
72.2mph

Pro 21/44
6 tooth 3.5 pitch
8250 RPM
1:1 ratio
78.3 mph

QD1 22/43
6 tooth 3.5 pitch
8250 RPM
1:1 ratio
83.9 mph


The ‘24 I have, that came with a 3.25, doesn’t limit speed but flashes the screen once over 50mph. Annoying for sure.

Venom has a great gearing calculator for those who want to play around with gearing options.

 

[Sheetmetalfab]

22/50 QD2
6 tooth 3.5 pitch driver
8250 RPM
1:1 ratio
72.2mph

Pro 21/44
6 tooth 3.5 pitch
8250 RPM
1:1 ratio
78.3 mph

QD1 22/43
6 tooth 3.5 pitch
8250 RPM
1:1 ratio
83.9 mph

Maybe my gauge is way off.

Get buddies running alongside and trying to pass when heading across the river bottoms and start squeezing the throttle a little too long.

The numbers definitely run way up.

 

[xring60]

23 boost qd2 165 3.25 65-66mph 6k
23 boost qd155 3.25 65mph 6k

At about 8:40 we did some drag racing
https://youtu.be/tP-zlDfyecI?si=LGj8DjPNubf4ZJJ4

 

[xring60]

My QD2 boost will hit 85 mph if I’m not careful on the way to the hill.

Lower gearing definitely wouldn’t hurt my track.

Dang that seems high!!!

 

[madmax]

How much does 300 more rpm raise the top speed numbers TRS posted? Most guys seem like they run the boost at higher rpm than 8250. Guess I need to play with the Venom calculator.