View Full Version : 64-pitch on a stock Kyosho plastic mount

2009.11.11, 06:45 PM
Not sure if anyone has asked this question, but would a 64-pitch differential would work on the stock Kyosho plastic motor mount?

Any combination between the pinion and the differential.


2009.11.11, 08:54 PM
Interesting question, but I'm not sure. Since you only have 3 motor spacers, I don't know if any will give you the right gear mesh between pinion and spur. If you go to the trouble of 64 pitch you should go with an aftermarket motor mount fine tuning the gear mesh.

2009.11.11, 09:39 PM
I had a good mesh on a RM mount. 12/53, with the big 1,5 spacer.

2009.11.11, 11:34 PM
You will note that Kyosho use 7T and 8T with the middle size spacer anyway. So the stock mesh is not perfect. As long as gears are not too tight or loose, they should be fine.

2009.11.12, 01:00 AM
One possible thing to try could be to find which 48p gear ratios correspond closest to which 64p gear ratios? For example, 48p Kyosho spur&pinion gears using a Kyosho Stock ball diff with a 44-tooth spur gear, the gear ratio for a 9-tooth pinion/44-tooth spur is 4.889 . The closest corresponding 64p gear ratio is 11/53 or 11/54, which ratios are 4.818 and 4.909, respectively.
I have not tested this idea out, but I would think the gear mesh would be comparable when trying to match 48pitch-to-64-pitch gear ratios as closely as possible. This method might allow people who like the Kyosho stock motor pods (Myself included:)) to use 64p diffs&pinions.
Other examples:
6/44 (48p) = 7.333
7/44 (48p) = 6.286; 9/54 (64p) = 6.000 ;
8/44 (48p) = 5.500; 10/54 (64p) = 5.400 OR 10/53 (64p) = 5.300 ;
9/44 (48p) = 4.889; 11/53 (64p) = 4.818 OR 11/54 (64p) = 4.909 ;
10/44 (48p) = 4.400; 12/52 (64p) = 4.333 OR 12/53 (64p) = 4.417 ;

I am not sure how far-apart the ratios can be and still have proper gear mesh, so this will need some testing.:)

Hope this helps:D

2009.11.12, 03:47 AM
Basing the spacing on gear ratio is not going to guarantee you a corresponding mesh. It should be somewhat close, but only with the spur that is the closest in size to the 44t 48p spur. If you use a smaller or larger spur, the size difference of the spur will make a big difference in spacing at that gear ratio.

you would have to figure out the distance between the motor shaft and the differential shaft. That would be the radius of both gears added together. Compare that distance with the 48p distances to decide what spacer to use. With more spur options on the 64p, you can fine tune the mesh a little better...

Theoretically, you should have more gearing options with the 64p than with 48p with the stock motormounts, but they may not be as precise of a mesh as they should be with 48p.

You will have to do a lot of trial and error testing to see what fits, perhaps someone may be able to do some measurements of the gears to see what would be the closest fit and a chart can be made of the compatable ratios...

If you are using 64p, it is much easier to buy an adjustable mount and choose the gear ratio that you want than to spend the time and effort on figuring out what gears to use with what spacers to get the speed you want. You can check the marketplace here for a used ones if you are trying to save money...

2009.11.12, 01:26 PM
Thanks everyone for your input. Obviously, an aftermarket motor mount is the ideal. One of my cars is using a PN motor mount with a 64-pitch.

I'm just curious if it can be done with the stock Kyosho mounts.

2009.11.13, 11:46 AM
@EMU - The more I think about it, you are right that just having the same or close to the same spur-to-pinion gear ratio isn't going to work well if trying to use 64p gears with the Kyosho motor mounts. I am not sure why I felt this would work, must have been before I had my morning cup of coffee...:)

Using 64p gears with the stock Kyosho motor mount(s) could still be possible, but EMU is right about it being a lot of trial-and-error testing to see what gearing has the best mesh. Since setting the backlash is so important on these cars in order to get the best performance, finding the best pinion/spur gear combinations could take a while.

On a side note, I have found the box-stock Kyosho pinions to work very smooth with the MR02/MR03 Gear Diff; Also the Kyosho Delrin Pinion Gears (part#MZW24) work well with the Gear Diff. For the Kyosho MR02 Ball Diff, I have found the PN Racing "Pro-Match" 48p pinion gears (part#400324) to work phenomenal. I don't have much experience with other companies' 48p ball diffs, but the PN 48p Pro-Match pinions should work great with those also. Thanks to color0 for making me go back and retry these PN 48p Pro-Match pinions.:) They are super silent, I give them 5 stars!:D