Originally Posted by justthisguy1292
looks like i'm not the only one with that snowmobile idea. I can't afford the $500 and 27lbs it adds to the bike. I'm trying to make my own. so far my idea goes like this. take two old mountain bike tires and cut them so you can stitch them together. cut out the metal rim in the tires that give them the stiff circular shape. that will be the actual track. Then i'm gonna use a bicycle hub i found at the dump as an idler pulley. It will trail maybe 18inches behing my back tire, mounted with two steel tubes i hacked off an old snowblower. I figured and bump would snap whatever i use to connect the tubes to the frame with. So i'll have them on some kind of a pivot(probably utilizing the rear axle) and rig up this rear shock i pulled off a cheap mountian bike that i found at the dump. the track will wrap around my normal tire and the bicycle hub. what do you think?
I would use a kevlar tyre for its flexibility, maybe a 29er tyre and use a 20" rear wheel to avoid the cutting and stitching of tyres.
I would imagine that norco pictured is very difficult to pedal with the drag of all those pulleys. I also think an engine small enough to power the bike would struggle to drive with the amount of drag. If you look at the motocross bike conversions to a tracked vehicle, they seem overwelmed and even with 60bhp struggle to propel the bike at a rate i'd be happy with. A motocross bike should never be overtyred as they need to be able to spin up like the snowmobiles do just to keep progress quick so that the engine does not bogg down. Overtyring a bike is often worse than a tyre with lack of grip and is certainly less fun. So I believe a small engine would struggle to make any progress and clutches would struggle to cope with the force that is required to move.