XRAY X4 - Build - Gear Diff & Solid Axle 

Thanks for doing these videos. I think a direct overhead camera would be batter than the one to the side. Presently, your left hand obscures the close-up view from the camera.

I'd be super cool if you guys could add all these X4 videos to a YT Playlist, like you do for your other cars. :)

Nice vids! I will grovel for more on the new X12!

What is the differential ratio on the X4 with gears in the back and solid in the front? I plan to use my X4 for USGT and or VTA. This would be on a medium-small course on carpet with med-high traction. Do you have any recommendations on what spur gear and pinion gears I should use? Some people have told me to go for an FDR of 3.5-3.9 but to calculate that I would need to know the differential ratio I guess. Any help is appreciated. Thanks

These videos are great. Get rid of that creepy music though.