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Old 11-02-2010, 11:14 AM
Tommytsunami74 Tommytsunami74 is offline
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Default Go kart using riding lawnmower transaxle

I'm building a gokart using a lawnmower transaxle and im running the sprockets off of the transaxle axle to the live axle and need to know sprocket sizes to use to to get from 7 mph to around 30 or 40 mph

the Forward-shift gear ratios are: 1st) 2.64:1; 2nd) 2.07:1; 3rd)1.30:1; 4th) 0.90:1; 5th) 0.67:1; and 6th) 0.60:1. Input pinion ratio is 2.31:1, and final-drive/differential ratio is 9.89:1. And the wheel size is 11 inches
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Old 11-02-2010, 11:26 AM
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There are so many variables in what you're asking for. Be a bit more specific. (Tire size, current final drive ratio, etc.)
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Old 11-02-2010, 01:49 PM
Tommytsunami74 Tommytsunami74 is offline
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the Forward-shift gear ratios are: 1st) 2.64:1; 2nd) 2.07:1; 3rd)1.30:1; 4th) 0.90:1; 5th) 0.67:1; and 6th) 0.60:1. Input pinion ratio is 2.31:1, and final-drive/differential ratio is 9.89:1. And the wheel size is 11 inches
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Old 11-02-2010, 06:12 PM
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What brand of transaxle is this? most lawnmower transaxles wont hold up to speeds anywhere near that.
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Old 11-02-2010, 06:26 PM
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Quote:
Originally Posted by devino246 View Post
What brand of transaxle is this? most lawnmower transaxles wont hold up to speeds anywhere near that.
One of the problems is that the entire transmission was not designed to handle those kinds of rpms and then the hp needed to take to to 40mph is likely beyond the scope of the transaxle.

Just a straight axle and a centrifugal clutch will give you good speed and reasonable low end.
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Old 11-02-2010, 06:57 PM
Tommytsunami74 Tommytsunami74 is offline
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I'm using a vertical engine and planing on changing gear ratios from the transaxle to the live axle to keep the transaxle at the same rpm's
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Old 11-02-2010, 07:08 PM
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You could be okay like that. Use the forums speed calculator to mess with the ratios until you find what you're after.
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Old 11-02-2010, 07:42 PM
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yea just use the trans axle as a jack shaft, keep all the ratios stock except for the trans axle to wheel ratio.
calcs i use (other than my head):
http://www.diygokarts.com/speed-calculator.html
http://gokartguru.com/engineering_tool_kit.php
http://www.compgoparts.com/Technical...Calculator.asp
http://www.rbracing-rsr.com/gearspeed.html
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Old 11-03-2010, 06:29 AM
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Wont you need to lock the built-in differential too?
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Old 11-03-2010, 03:44 PM
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If it truly is a transaxle, wherein the output is two axleshafts, then yeah, Devino makes a very valid point. If it's really a transmission that has one output, then, no problem.
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Old 11-03-2010, 08:34 PM
Tommytsunami74 Tommytsunami74 is offline
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I was thinking I would run a sprocket off each axleshaft
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Old 11-04-2010, 01:01 AM
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Could you disassemble it and weld up the diff? That way you could out just one of the outputs.
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Old 11-04-2010, 04:01 AM
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Better to go with Modelengineer's idea- less weight, less moving parts, less expense. As long as- the gears are actually made of a material you can weld, not something cheesy like cast aluminum.
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