Gear ratio question.

[usmcdoc]

Looking to buy an up gear kit to compliment my minarelli BBK. This is what I found. it is a complete set. I am wondering if anybody knows what the numbers mean...what the stock numbers...ratio?....are...
"Complete performance kit gear set transmission yamaha jog top end speed 41/52 combination 50cc 2 stroke"
I can strip a scooter down to nothing but parts and re assemble it....can fix about 90% of problems...then come here for the other 10% or so.....but gear ratio's and all that math confuse and make no sense to me. Buddy told me it would give a 15% increase....but he is an auto mechanic....so I think he is just guessing...
Thanks in advance for the help...Glenn :riding:

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[reveeen]

No one, and I mean: no one, will be straight with you about what is in your final drive.
I *suspect* it is simply because they don't know.
You can count turns of your clutch bell vs. axle turns, and you might get close, but last time I checked close only counts with horseshoes and hand grenades.

So, unless you have the good fortune to own either a "real" Honda, or Yamaha, (and a "real" manual) you are going to take that thing (the final drive) apart and count the teeth.

Once you know what you have can you make an accurate guess as to where you want to go.

Sorry

Any recommendations I could find is: with a 70cc BBK a 20% up-gear is not unreasonable.

On my Zuma I installed a Malossi Upgear Kit: Ratio 16/40 (20%) and I'm good with that.
(16/40 being the "primary" gear set, or 16 teeth on the clutch shaft (input shaft), 40 teeth on the driven gear (the first driven gear, on the short shaft, that is a press-on)

[90GTVert]

Apr 24, 2012 1:31:53 GMT -5 reveeen said:

No one, and I mean: no one, will be straight with you about what is in your final drive.
I *suspect* it is simply because they don't know.

Yup. There are multiple gearsets in minarellis. I've seen from about 8:1 to 14.6:1 final drive ratios.

Here is a listing of some gear ratios gathered from various members :
49ccscoot.proboards.com/index.cgi?board=transtech&action=display&thread=1265

Here is an explanation of what's what and how to figure out the final drive ratio from counting teeth :
49ccscoot.proboards.com/index.cgi?board=transtech&action=display&thread=3472

[usmcdoc]

90GTvert.....well then I where they come up with "Complete performance kit gear set transmission yamaha jog top end speed 41/52 combination 50cc 2 stroke"

When scrappydog list the available gear sets in 13/34 and 14/34....where do the other company get 41/52?...way confused...

[90GTVert]

I have no idea where they plan to use a 41/52. Maybe it's a typo or since it shows all of the gears perhaps it's only listing the 2 largest gears?