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Title: model 9 gearing
Post by: ghardcastle on January 16, 2012, 08:34:50 PM

Hi, can anyone tell me how many teeth my 1930 model 9 final drive sprocket should have? Mine has 16 and it seems low geared, any ideas where I might source a larger one? Many thanks.

Title: Re: model 9 gearing
Post by: j hood on January 16, 2012, 08:53:54 PM

If you send me your Email address I can send you 2 files from my deteriorating 1st edition hand book that lists the gear ratios available as standard and the options ..John

Title: Re: model 9 gearing
Post by: j hood on January 16, 2012, 09:15:13 PM

If you have a 24 tooth engine sprocket( listed as standard on a 3 speed box) and a 16 tooth gearbox sprocket then the gear ratio is 4.6..
If my maths are right then with a 3.25x19 rear tyre this should give a theroretical 49mph @ 3000rpm.
A larger rear wheel will give more speed as at 3000rpm the rear wheel is turning at 652rpm.
If you get up to 5000rpm then the rear wheel is doing 1086rpm and you will be flying at 82mph.
..john

Title: Re: model 9 gearing
Post by: ghardcastle on January 17, 2012, 04:59:48 PM

Thanks John, that would be really useful. My email address is t_hardcastle@sky.com

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General Category => Technical Discussion Forum => Topic started by: ghardcastle on January 16, 2012, 08:34:50 PM