Gear ratio help


Old 04-09-2016, 08:50 AM
Tech Apprentice
Thread Starter
iTrader: (1)
Join Date: Jan 2016
Location: Long island
Posts: 57
Trader Rating: 1 (100%+)
Default Gear ratio help

Ok so I'm still at a loss at finding a good gearing for my tamiya dn-01 with the super stock bz motor. I have tried multiple Spurs and pinions with little difference in top end and literally zero difference in acceleration. Now while reading last night I found the BZ motor needs to have a ratio of 9-1 to 11-1. Now my question is using either the stock 79t or 77t option pinion what tooth pinion should I use? I also have 69t spur and 81t spur.
I have 20-25t pinions. In the dn01 manual gearing list it doesn't even have those ratios listed.

Any help in getting this 9-1 to 11-1 ratio is appreciated
Rb4276 is offline  
Reply With Quote
Old 04-09-2016, 07:17 PM
Super Moderator
Join Date: Oct 2007
Location: Rochester Hills Michigan
Posts: 7,232

Final Drive Ratio = transmission ratio x spur/pinion. That model appears to have a 2.6:1 transmission ratio. Rearrange to work backwards.

For a FDR of 9 with your gears for example:

2.6 trans x 79T spur / 9 FDR = 22.8T pinion (23T)
2.6 trans x 77T spur / 9 FDR = 22.2T pinion

Can't quite reach a FDR of 11 with what you have, closest appears to be:

2.6 TR x 81T / 20T = 10.53 FDR

Looks like a 81T and 21T combo would put it right in the middle at just a bit over 10 FDR.
Dave H is offline  
Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service