Mi9 diff height explanation!

The Mi9 comes with low trans housings, which are 2mm lower than the option U8729 high trans housings. This relates to diff height and inner upper arm mounts.

For medium to high grip tracks, I suggest the U8729 trans housings. Remember to use same housings front and rear (you need 2x U8729) and with the high trans housings your inner upper arm mounts are already +2mm built into the bulkhead.

The new optional alloy +0.5mm eccentrics are a fantastic tool for finer adjustment of diff height. You can go even lower or higher than with the kit eccentrics. Remember to use same height front and rear (you need 2x U8777).

In extra high grip we use the highest diff and spool position to create the most amount of corner speed (U8729 trans housings and U8777 eccentrics up), but this will generate less overall traction. To create more traction, you have to lower the diff and spool, therefore on low grip tracks we tend to use kit low trans housings.