Originally Posted by Waflet

Hideeho
I run a Savox 1258 & love it. I have also used the d770 & found it quite decent. I've got 2 kids w/ rc cars, the youngest has the stock servo, the oldest has the d770 & I have the 1258. The jump from stock to the d770 is incredible, the jump from the d770 to the 1258 is dramatic, but no where near as big as from the stock to d770. If you are on any kind of a budget at all, or have never used a fast servo before, the d770 will blow you away (& save you a bunch of $ for tires & practice), until you use an even better servo.

The Savox fast servos (1257 & 1258) draw lots of power. If you have other things in your system that bottle neck power (Spektrum dsm1 but not dsm2 receivers, Castle ESC, etc) you will run into brown out issues. When a brown out occurs you can loose stearing partially (doesn't get to full lock & feels like a push) or fully, or you can loose trottle, again either partially or fully. If this occurs you need a glitch buster. Most any LHS should stock them & they run $5-$6.

Wildcat nailed it on the gear mesh for the noise. Even if you set the gear mesh perfectly, 1 landing on the rear end can push you motor forward & tighten your gear mesh. While driving you can tell this by how much the buggy slows down when you let the trottle go. It should roll smoothly to a stop in several feet. In severe cases the rear wheels will lock right before the car stops even with no brakes. The way to solve this is to not goose it right before take off & roll off the throttle while in the air. Done properly the car attitude will follow the arc of the jump & land slightly nose down on the down side of the ramp. Good luck nailing that every time, but that is why you saved $ on the d770, to get more practice time.