Adding Idler Wheels

Dear Ralph:
I was wondering what your thoughts are on adding the “4th wheel kit” and “extra idler” wheel kit? I snow checked a 2010 Ski-Doo Renegade X and would like to know if it is necessary to have them installed? Do they really make that much of a difference? Will they reduce rolling resistance by that much?
I previously installed both on my 2005 Yamaha RS VectorER. I believe the extra idler’s did help in hyfax wear by bridging the gap between the rear wheel’s and the front set of idler’s. Mechanically it makes sense. So why does the manufacturer not install them?
Paul DeKay
Ontario,Canada

Cost, cost, cost. You build 20,000 sleds with an extra $5 in there and guess what? That’s $100,000. Do that with ten parts here and there and you get the idea, I hope. It is usually that simple.
We are talking about two different things here, rear axle wheels and extra idler wheels. In my experience every sled needs at least three wheels on the rear axle, the fourth one is a matter of usage. If it is studded, then yes, the fourth wheel is really nice to have in there to prevent track derailing due to the added side forces applied by the addition of traction products. So, if your Renegade has three wheels and you will not be installing studs, it is more a matter of insurance but I wouldn’t worry about it. Any sled with only two wheels on the rear axle (like the TNT) needs the third added, in my opinion. Any sled with studs needs the fourth. That’s my opinion.
As for the extra idler wheels (not on the rear axle) then we have a different situation. Again it is a cost thing for the OEM, but also a weight thing. Yes, they hurt rolling resistance, to the tune of about 2 mph typically, and yes they help greatly with reducing hyfax wear. These should be installed on any sled that will see high miles or where hyfax wear is an issue. It really depends on the snow conditions, mountain guys will take them all off and never have a problem until the spring where the snow gets hard, then they fry the hyfax. In good snow you really don’t need them, but when the snow gets hard they are really going to save your hyfax.