15" to 16" conversion??? 1997 Ski Doo Summit 670

[SnowriderND]

removing 15"x136 track and skid and going to a 16" x 144 skid and 2" paddle track... heard its easy to do but never done it... I know I need to roll the chain case and go to extroverted drivers... any suggestions????


I want the benifit of the 150+ track length without going that long.. 16"x144" should give me the same snow contact as the longer 15" wide tracks. Has anybody ever done this conversion? I hear it can be done... but not 100% sure. any advise or tricks are greatly appreciated.

 

[highmark00700]

removing 15"x136 track and skid and going to a 16" x 144 skid and 2" paddle track... heard its easy to do but never done it... I know I need to roll the chain case and go to extroverted drivers... any suggestions????


I want the benifit of the 150+ track length without going that long.. 16"x144" should give me the same snow contact as the longer 15" wide tracks. Has anybody ever done this conversion? I hear it can be done... but not 100% sure. any advise or tricks are greatly appreciated.

I have done a few on 16" conversions on zx chassis but not an s-2000, but the chassis are very similar so I think it could be done. On a zx I had to reverse some rivets so they were smashed on the outside instead of the inside. The studs for the chaincase had to be modified (grind about half of the head off and remove the washer) to gain extra clearance. Other than that Its pretty simple. If I remember correctly we were doing a 5/8" down and 5/8" back rolled chaincase to clear the 2" lug. One other option is to go to the 8T drivers. Definately a lot less work than rolling the chaincase but doesn't work as well in the powder. One issue I had with my zx when i put anti ratchet drivers on it was the tips of the rails hit the drivers, so you either have to shorten the tips of the rails or move the skid back about 1 1/4" to 1 1/2". Also you dont have to run extovert drivers unless you are running high horsepower. The non x model revs didn't use extroverts but if you can fit them they are worth it.

 

[Ox]

If you go to a modern 3" pitch track you can go to a 7 tooth driver that is enough smaller to allow the 2" to pass.

The standard F/S chassis would pass a 1-3/4" track with 9 tooth drivers no problem.

9 x 2.52 = 22.68 cir ~ pi = 7.22" diameter driver

7 x 3 = 21 cir ~ pi = 6.7" diameter

Difference of just over 1/4" per side, as well as a drop of .08/1 gear ratio change to help pull the bigger track better.

Others have obviously had better luck with Doo drivers than I have. Other than adding extroverts, I have never been able to keep a Doo track from ratcheting in heavy use short of tuning them tighter than a banjo string.

Add 3" extro's and leave it semi loose.

I wouldn't bother with a drop/roll, but would just slide the skid back to accomidate the extra track length. Don't forget to add in the extra 1/4" (heavy on the 1/4) needed for the smaller drivers.

As was said - just grind your way to clearance.

Also - add a worsher or two on both sides of the rear scissors mount to add some clearence room in there.

Probably the most carefull part of the whole deal will be location of the drivers when you press new ones on. When you go to zero side clearence, placement is everything!



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[xpspenziv]

rev chaincase bolts.
the screw in the footwell needs to be turned around. nut out.
washer in drop brackets.
8 tooth drivers and i put a 2.25x16x151. slid skid back 1inch and down 1inch.
didnt have to drop and roll the chaincase
x2 on setting up drivers. scribe the axle before you press the old ones off.

 

[SnowriderND]

Thanks

I will post after the conversion is done... I greatly appreciate the info.... you guys rock!!!!!!