Torque converter talk

Mini Bike & Go-Kart Parts


Active Member
Hi Guys. I know there’s more than one of you out there that can help me so here goes. I have a couple of bikes , one with a 196cc clone and the other a 212 cc clone. Both of them have Comet torque converters with 41 chain 12 tooth gears feeding a 72 tooth sprocket on 15 inch diameter wheels. I can’t keep the front wheel on the ground and top speed is awesome. Is there a better option as the 72 tooth sprocket is huge. I’d like to try a 10 and 54 combination but before I spend the money I’d like a second, third or fourth opinion.
Thank you and Stay safe.


Active Member
Depend on the drivers size and weight. You could up the 12 to 15 or more it will be cheaper than the big sprocket. And you will have a real top end.


Well-Known Member
If you like your 6/1 ratio but just want a smaller rear sprocket why wouldn't you go with a 10 and 60? Then again the 10 and 54 may not wheelie as easy as the 12 and 72. I wouldn't know how much the top speed would change but you would think the rpm would be lower at top speed with the 10 and 54.
I know that on the tall tire Coleman mini bikes many were not happy with top speed performance with the stock 5/1 ratio and a torque converter. They were much happier with a 6/1 (10 and 60) or 6.6/1 (9 and 60). There is one guy on youtube that got 47 mph with 6.6/1 gearing with a governed 212 engine he never even opened on his Coleman.


Active Member
Thank you friends. I really don’t like the 72 tooth sprocket, looks like it belongs on a lawn roller or something. If I understand correctly it seems as though the ratios for performance are similar to that you find in those gear ratio calculators. These bikes are rockets at that 6 to 1 ratio, hmmm maybe best left alone and put on some wheelie bars.
Best wishes and stay safe.
Depends on what you want. If you want to climb up steep grades without bogging down the engine go with 60. If you want a higher top speed go with 54.There is always a trade off.


Active Member
Hmmm I think you’re right. The 6 to 1 works exceptionally well. I’ll see if maybe a 54 and 9 if the 9 tooth sprocket is available for the TC. I’m sold either way. It’s the size (OD) of these 41 chain sprockets thats putting me off.