For running on astro,I'd get myself 2 sets of front tyres,yellow mini-pins/spikes for the dry,and green ones for the wet,or as I've read,staggered ribs seem to be quite a good choice too.
As to your gearing,with a 17T motor,I wouldn't chance a 27t pinion with it, possibly a 25t at max,you can try it,but watch the temps in your motor & ESC.
I'm going to try filming another vid of her running on tarmac this time,which should be roughly the same speedwise as I'd get on astro. I'll still have the stock Clash 21t in her,just to see how she performs before I put in the Speed Passion 3000kv brushless unit. I think,that I'll need to drop back to a 24t pinion for that though.
