I need to know what gears to run in my sons Indy 500. I'm stretching it from 121" x 1" to a 136 x2" camo. track. the gears that came in the sled are 21/39. Anybody know what gears came in the SKS or RMK?
That sounds like the stock gearing for my 600 IQ Switchbacks. I changed them to a 19/41 ratio (600 IQ RMK), also to pull 2" paddle tracks. This can be done without a chain change (both are 76-pitch in length). Might be a good place to start. Chain length changes will start to play into the mix with more ratio changes. Charge on.
Well once started....You may have different chain lengths than I mentioned, but chain length will drive all your gear ratio selections, remember there is a maximum size lower gear. Also, you might try a 36-degree straight ramp helix as well. This helix allowed a 121'' XLT I once long-tracked hold its rpm where it needed to be. Ultimately you will have in your possession a multitude of gear sets and assorted chain sizes.
There is a good chance you will end up using 8 tooth drivers instead of the stock 9 tooth. This will effectively lower the gearing by 1.125 times. I had a '94 XLT that I did this swap in but I only used a 1.75" paddle and used the 8 tooth drivers, plus a gear swap to keep the motor happy.
I just installed a 133x1.5" track in my '93 440 SKS yesterday and it is tight. It came with 20/39 gears and I plan to change to a 18/41 and use the same chain. I selected this as it is the stock gearing in a newer 550 Trail RMK which pulls a 136x1.25 track.
Thanks for the replies, I want to try and stay with the 9 tooth drivers if I can, I'm in the process of doing a drop and roll on it right now so it will have all the clearance it needs, as long as it can pull the track. Is 41 the largest gear I can get?
