Hitchcocks Forum

Hi, I'm looking for a bit of software (or Java) that calculates the gear ratios of the 4 speed gearbox.

Anyone got any info on this?

Cheers
Ian W

Hi Ian.

I have a small xl spreadsheet that I just adapted to my 5 speed EFI. It is set up for 19 inch wheels, 17/18/19 tooth sprocket. you can read rpm vs speed in any gear. It was originally meant for a 4 speed Bullet, but it could be retro'd from what I have. I can send the file to a mail address.
Cheers TrevorCH

Hi thanks for the offer.
Does it have the ability to calculate different teeth on the gears / pinions?
I have a lot of pre 1959 gears and I want to mix and match them to see what ratios I can get out of them.

Hi IAN W---------it might be an idea to check that the DP (Diametral Pitch)of the older gears matches any later ones. They probably will, but given the nature & history of these machines I wouldn't take anything for granted.

Sorry Ian W. My XL only considered the given overall ratios i.e Mulitplicative value for primary, gearbox and final drive and with 19 inch rear tyre. You can select final drive sprocket from 17, 18 or 19 teeth. This just allows you to see at what road speed you will meet peak torque and power in any gear. Cheers Trevorch

Hi, I wrote one a few years back when I was developing my Bullet MX bike. Drop me an email if you want it [email protected]

Hi thank you all.
Alan R, Diametral Pitch?

Have you tried this: http://www.gearingcommander.com/

Hi, no this is if you know the ratios in the first place.
What I want is software that tells you what each ratio is.
Like the trials or high ratio gears on this site, it states the ratios for each gear. I was hoping for what ever software calculated those ratios.

Cheers anyway.
Ian W