Gearbox Help/Idea

[moorsa]

Right i was wondering if i had two gearboxes one of the older am6 engine and one of the new if i could make a close ratio gear box, what i need is the no. of teeth on of the gear on a close ratio gearbox of any and if this can be done?????

[RS_Patrick]

No you cant make an close ratio gearbox from that.
You would need difrent size gearsprockets.
Better spend your money than on a gearbox like a Doppler or Bidalot.

[moorsa]

1. the old am6 engine has different no. of teeth to the new 1
2. i can get different ones from beed speed which are top performances

[RS_Patrick]

All AM6 engines are internaly completly the same, only external they look a bit difrent.
TP gears are the same size as stock, only there made of a stronger material.

[williamr]

The pairs of gears need to be matched so that they mate up properly. The combined radius of the pair has to equal the shaft spacing.

You can make up pairs of gears if you're handy with a lathe and miller or have access to a modern gear cutter, but mild steel will need hardening.

Rob

[RS_Patrick]

I would just buy this gearbox, Really cheap compaired to other brands.

[williamr]

I would just buy this gearbox, Really cheap compaired to other brands.

It's a lot easier than making your own.

Rob

[oribaka]

I hope you're using this as a race bike, 'cause I'd say that a close ratio gearbox would be a bitch to ride in the streets?

[Davido]

Forgive my ignorance, but what actually is a close ratio gearbox?

Please nobody post any "exactly what it says on the tin" answers. :p

[Woodinator]

A close ratio box is where all the gears are quite similar, so there isnt much difference between the gears. Its best for engines that have short powerbands and its needed to keep the revvs in the powerband for maximum acceleration.
(Shoot me if im wrong)

[RS_Patrick]

Your rite, but its not the case will all gearboxes, some got a longer first gear so you can keep it in first a bit longer for better acceleration with a powerfull setup.
i know that on the doppler atleast the 1st gear is difrent, not sure about the other gears.

[oribaka]

A close ratio box is where all the gears are quite similar, so there isnt much difference between the gears. Its best for engines that have short powerbands and its needed to keep the revvs in the powerband for maximum acceleration.

That's correct - and it's very usefull for racing, as you're most likely only using a bandwidth of max 5.000 rpm when knocking it down the straight, so you're sure to keep within the power-range at all time.

[moorsa]

how wud i go abwt making 1 william and how much thanks

[RS_Patrick]

Its cheaper to buy the Doppler gearbox than making one your self.
Doppler gearbox is 361,95 euro Here so thats about 250 pound/465 dollar.

[Charles]

A close ratio box is where all the gears are quite similar, so there isnt much difference between the gears. Its best for engines that have short powerbands and its needed to keep the revvs in the powerband for maximum acceleration.
(Shoot me if im wrong)

well the rs50 already has a close ratio gearbox, as it indeed has a very short powerband (made more pronounced by having a racing exhaust on).

The opposite would be a standard small engined car with linear power delivery, where more of the rev range is useable, for example on a diesel engined car, whereby a really close ratio gearbox would be inefficient.

It's all about the suitability of the applicaton, but as standard, or even modified to a reasonable degree, changing the gearbox and making specific ratios (such as is used in drag racing) is quite a serious step up the modification ladder and really only for serious racing. It would most probably be highly impractical to have such a machine for use on the road. (16 gears on some of the top racing 50's with powerbands 500rpm wide!!!)

(The latest thing in helping riders to get round the race track is in having the bikes fuel injection setup to follow the ECU programmed with a map of the track in so it gives the maximum amount of power theoretically possible to use round each given corner. Pretty you might think, but that takes some fun out surely...just a little interesting fact...)