[greencactus3]

not for first but for occra. our team has been successfully just bolted our sprockets to our wheels. and the wheels have bearings. the shaft is in those bearings, and collars hold the wheels from moving sideways. so basically our shaft is free of our wheels/sprockets. simple and works well. if you had good bearings in the wheels, you can eliminate the bearings to hold the shaft. if you really wanted it to spin under sideloads(such as turning with 4wd or plain being pushed sideways), you can actually get bearings..... just cant remember the name of the bearing right now.... the kind for pressing loads. GAH. cant rememebr any terms lol. like tiny turntables ish..... sorry. i really cant rememebr the term right now. well anyways, if the sprocket is solid to the wheel, wheel and tire dont slip, and chain doesnt slip, wheel doesnt wobble=sprocket doesnt wobble, you're pretty much set.
not hard to do. but this has been working for us well in OCCRA.... where we dont experience as much torque and shtuff.. so i unno about first.