Thanks 0verkill! Turns out gearing chart I posted earlier is rubbish anyway, with min pinion size 14T:
Originally Posted by
Matthew_Armeni
The smallest pinion you can run with the split diff and the 44 tooth spur is 14 tooth. If you run the old diff mount (and omit the center brace - or shave it down a lot) you should be able to fit a 12, definitely a 13. I haven't run a motor that needs to geared that low in a long time and I can't remember for sure if the 12 fits. A 13 will (with the old mount) and gives you the same top speed as a 1900kv motor geared 18/44. A 14 tooth is a little faster than a 1900 geared 19/44.
http://www.rctech.net/forum/electric...l#post14403352
Basically means when running 6S, the possibility of 176 mm tires with the 14/44 minimum gearing translates into max ~1300 kv for minimal of ~43 mph no-load, which might be a bit higher in reality with those huge tires ballooning and compensating for RPM drop under load (real world example:
http://www.rctech.net/forum/13684717-post7.html).