bam.bam

In case anyone is interested...

This is for using a 49T or 47T size spurgears in combination with 14T-19T size Clutchbell.


Spur Gear size/Clutch Bell size

Max Torque (Low End)
49T/14T
49T/15T
49T/16T
49T/17T = 47T/15T
49T/18T = 47T/16T
49T/19T = 47T/17T
47T/18T
47T/19T
Max Speed (Top End)


Please keep in mind, some combo may not fit (limited space) but at least you have an idea how the gearing goes.
Also tire diameter and weight has effects so this is based on stock Savage rim/tire combo.

gerwen

Here is a more complete listing of gear ratios based on gears i've seen available. It is listed from shortest (highest torque, lowest top speed) to longest (lowest torque, highest top speed)
I think once you get above a 16T bell, the 52 spur is too big, but i'm not sure about that.
As you can see there is only 2 sets of gearing that is equivalent, the 49/16 and 52/17. There are others that are close in ratio, but not the same.

This list really allows you to know which way you're going when switching both at the same time. Good idea in putting it together bam bam. I just extended it and used excel to calculate ratios and sort them.

Max torque, lower top speed
52/13 4.00
49/13 3.77
52/14 3.71
47/13 3.62
49/14 3.50
52/15 3.47
47/14 3.36
49/15 3.27
52/16 3.25
47/15 3.13
49/16 3.06
52/17 3.06
47/16 2.94
52/18 2.89
49/17 2.88
47/17 2.76
52/19 2.74
49/18 2.72
47/18 2.61
49/19 2.58
47/19 2.47
Min torque, Max top speed (if the motor is strong enough to pull the gear through it's entire rpm range)

Buzzbait

Here's what I go by.

bam.bam

Thanks for the addition and the more detailed calculations Gerwen!!!

By the way, what formula did you use to get the calculation results?

I was just going by teeth count and that is why 3 seemed to be the same gearing. Well close to each other anyway.

bam.bam

Buzzbait, Appreciate your contribution as well.

That's a nice chart. haven't seen that one before.

bam.bam

I just looked at the chart more in detail and it indicates the the 4.6 engine can be fitted with a 49T SG and 17-19 CB.

Now I have a 4.6 and the max size I was able to fit was a 49/18.
The meshing for this seemed a little tight to me with no more movement/space to mount the engine bolt. Also the engine is sticking out of the TVP already.
I was thinking of dremeling the base plate a little to give some play and room to fit the 49T/18T combo.

Well I guess what I getting at is the chart correct to indicate a the bigger 49T/19T combo fits and work ok?

Can anyone confirm this?

jombo

lol. i use that paper chart to set my gear mesh with.

jombo

i had the 15/52 in mine,the mesh was too tight and i did dremmel about 1/4 inch to make it fit,but this was with a 25,not the 4.6

gerwen

Simple, divide the Spur teeth by the CB teeth, that gives you the ratio.