Torque converter talk

[Oldyellow]

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.
Rick

 

[Cuda54]

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.

 

[SAS289]

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.

 

[Oldyellow]

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.

 

[Rapidrob]

10 or an 11 to a 60 tooth.

 

[Oldyellow]

Not 10 and 54?

 

[Rapidrob]

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.

 

[Oldyellow]

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.
Thanks