Anti-ratchet drivers

[unchained]

i have been running 10 tooth drivers(not extroverts) on my rx for a few years now. they reduce the track angle slightly, they make the speedometer read perfect, odometer will read low about 9-10%. they also increase the gear ratio so re-gearing may be required.

Although their totallly different sleds, its GREAT to know a recent Yami has had success with 10 tooths. Im excited aout all of the benefits you described if they pan out on my sled and as far the gearing is concerned, half of why Im going with 10 over 9 tooth extros is to gear this torque monster up anyhow.

As far as the speedo reading 9-10% low with 10 tooths, wouldnt this change bring the dream-o-meter closer to "accurate" since they read fast to begin with?

 

[TurboJamie]

I don't think that helps much on whether 10t extroverts will fit under the FX Nytro!

Yeah right...Now Im worried about clearance for the rail tips AND I just found out now why Cat went from 10's in 03 to 9's because the 10's didnt have enough ground clearance and would bend he driveshaft if you crashed on the driver.
I cant really determine if either of these issues will apply to the Nytro until its together so I can lay it all out and do some measuring and this Yami driveshaft removal isnt exactly fun to re-do once back together.

Guess this rain and warm up is about the only good ting going for me right now--at least Im not super rushed with good snow right now but of course the snow and cold will be back soon....
Ryan

We have one running the doo drivers on stock rails no problems put your worries to rest. My apex I had to trim the rails but not on the nytro. Have fun.

 

[Mikey]

TurboJamie you running 10 tooth or 9 tooth?

 

[08NitroRTX]

WHEW! Thanks that is good news!

 

[stock]

TurboJamie I would like those mesurments if you dont mind.

 

[TurboJamie]

OK Im running 9 tooth I'll look for the piece of carboard I made the sketch on when I get home tonight.

 

[Alatalo]

I have some vibrations from my track after installing Whalbros extros and a 1,75" track.
Im not sure if my dealer was aware of these arrows when they installed them.

If you get the arrows out of alignment I am not sure that you will even be able to re-install the track...?
If you do you will for sure get some serious vibrations...

I seem to remember that the internal cogs of the Wahl bros extroverts have got no track clip "cut-outs". I have never used Wahl bros extroverts in any of my own sleds, but I have been informed that the lack of track clip "cut-outs" can cause some vibrations. These vibrations will eventually go away because the track clips will make these "cut-outs" themselves (kind of break the internal cogs in...).

Also, a 1.75" track itself will, in general, generate more vibrations than a lower lug track, especially on hardpack.

 

[TurboJamie]

I have some vibrations from my track after installing Whalbros extros and a 1,75" track.
Im not sure if my dealer was aware of these arrows when they installed them.

If you get the arrows out of alignment I am not sure that you will even be able to re-install the track...?
If you do you will for sure get some serious vibrations...

I seem to remember that the internal cogs of the Wahl bros extroverts have got no track clip "cut-outs". I have never used Wahl bros extroverts in any of my own sleds, but I have been informed that the lack of track clip "cut-outs" can cause some vibrations. These vibrations will eventually go away because the track clips will make these "cut-outs" themselves (kind of break the internal cogs in...).

Also, a 1.75" track itself will, in general, generate more vibrations than a lower lug track, especially on hardpack.

The track will go one with them out of phase I saw that one first hand last year on a friends sled that did the install sucked the top end right out of it too. You are correct the whal drives are not machined for the track clips. After seeing and using both sets the Doo drivres seem to be superior in design and also in grip, meaning they use a longer portion of driver grabbing your drive shaft so there is less chance of slippage on the shaft its self.

 

[Alatalo]

I have installed a set of Ski-Doo 9Tx2.52 extroverts (#504152503) in my Nytro couple of weeks ago. If anyone is interested, I can provide the exact measurements by Friday afternoon (sorry, they are back home and I am not...).

 

[unchained]

OK Im running 9 tooth I'll look for the piece of carboard I made the sketch on when I get home tonight.

Before I press theses 10's on and put it all back together, is there any way you can do some measuring with yours together with 9's and give an idea if the 10's will clear? Thanks!!!
Ryan

 

[Alatalo]

Sorry, I forgot I had the measurements also on a different computer...
I combined the information from the FX Nytro service manual with the information from the Ski-Doo racing manual and ended up with the following measurements:

From the LH side (speedometer side) of the FX Nytro drive shaft

to the centerline of the LH Ski-Doo extrovert driver: 123.8 mm
to the "inside surface" of the LH Ski-Doo extrovert driver: 147.25 mm
to the "inside surface" of the RH Ski-Doo extrovert driver: 325.35 mm
to the centerline of the RH Ski-Doo extrovert driver: 348.8 mm

From the RH side (sprocket side) of the FX Nytro drive shaft

to the centerline of the RH Ski-Doo extrovert driver: 179.9 mm
to the "inside surface" of the RH Ski-Doo extrovert driver: 203.35 mm
to the "inside surface" of the LH Ski-Doo extrovert driver: 381.45 mm
to the centerline of the LH Ski-Doo extrovert driver: 404.9 mm

Distance between the centerlines of the Ski-Doo extroverts: 225 mm
Distance between the "inside surfaces" of the Ski-Doo extroverts: 178.1 mm

I installed my Ski-Doo extroverts according to this and they seem to line up perfectly (same distance to both sides of the tunnel and no problems with misaligned track). Also, I prefer to give out measurements to the centerlines and the "inside surfaces" only since the hub width seems to have a very slack tolerance (different between different extroverts).
Regarding my definition of "inside surfaces", these are the surfaces where the measurement "B" is taken according to the attached picture from the Ski-Doo racing manual.

Hope this helps.

 

[TurboJamie]

OK Im running 9 tooth I'll look for the piece of carboard I made the sketch on when I get home tonight.

Before I press theses 10's on and put it all back together, is there any way you can do some measuring with yours together with 9's and give an idea if the 10's will clear? Thanks!!!
Ryan

I don't think that the 10's will fit from looking at it thats forsure.

 

[Mikey]

That diagram wont work as the nytro and the ski-doo tunnels/shafts are different widths/lengths. You will have to measure where the old ones are and do the math unfortunately.

 

[Alatalo]

That diagram wont work as the nytro and the ski-doo tunnels/shafts are different widths/lengths. You will have to measure where the old ones are and do the math unfortunately.

Please read my post again. The math is already done. The picture is attached only to show the meaning of "inside surfaces"...

 

[Mikey]

Sorry yes I read it better now you are correct...