Allen’s Tech Tips, “Calculating Gearing”
Playing with the gearing on your snow bike is a vey common modification that a lot of guys do. It’s been hard to set a standard for measuring gearing on a snow bike in comparison to the tires or to another snow bike. For me, I do not go off a calculated gear ratio. I measure the track inches of roll out to one revolution of the engine sprocket. This will show you how far you would travel with one revolution of the engine counter shaft sprocket. This does not compare transmission gearing. It is used only to set a standard for gearing snow bikes, so that we can all go off of the same thing when talking shop tech.
How to do this:
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For example:<O</O
Stock gearing on the ST Mtn. Horse kit using a 2.86 pitch 7 tooth driver with a 13 (engine) -17 (jack shaft) / 17-20 (chain case) = 13-1/8” of track roll-out.
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Please post up the performance advantages of the gear setup you run along with the track roll out measurement and bike model. Also note how tight or loose your chain was and if you had to modify the length from the stock MH chain length.
Playing with the gearing on your snow bike is a vey common modification that a lot of guys do. It’s been hard to set a standard for measuring gearing on a snow bike in comparison to the tires or to another snow bike. For me, I do not go off a calculated gear ratio. I measure the track inches of roll out to one revolution of the engine sprocket. This will show you how far you would travel with one revolution of the engine counter shaft sprocket. This does not compare transmission gearing. It is used only to set a standard for gearing snow bikes, so that we can all go off of the same thing when talking shop tech.
How to do this:
- Mark a line on a tooth of the engine sprocket and on the engine case that are in line with each other.
- Mark a line on the hifax and on the track that are also in line with each other.
- Rotate the track forward while looking at the engine sprocket. Stop when you get to 1 revolution.
- Measure the distance between the line on the track and the line on the hifax.<O</O
</O
For example:<O
</OStock gearing on the ST Mtn. Horse kit using a 2.86 pitch 7 tooth driver with a 13 (engine) -17 (jack shaft) / 17-20 (chain case) = 13-1/8” of track roll-out.
<O
</O<O
</OPlease post up the performance advantages of the gear setup you run along with the track roll out measurement and bike model. Also note how tight or loose your chain was and if you had to modify the length from the stock MH chain length.
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Thanks
