Not sure if I'm posting this in the right place, this is my first post. I'm looking for the absolute cheapest motor that I can buy that won't crap out on me. I wanna go at least 35 miles an hour, I'll be putting it on a Mongoose 29er Impasse. I'm 6 foot 2, 165 pounds. Ebay seems to be letting them go for around $160, would these be ok to get or would they explode on me?