a bike is a bike(for the most part) when it comes to stability IMO. The only thing that may have an effect is the stiffness, as a stiffer bike wouldn't give the little bit of flex...but I doubt that's even really a factor. Just slowly increase your speed and the stability will come. I used to be unstable doing 30 mph...I can do 40+ now with no issue. Don't know about anything really over 45 b/c there are no hills that long/steep/safe to go bombing down at those speeds.