The good thing is you aren't getting badly hurt when you take your tumbles. But for the most part I would hope that these tumbles are rare and won't keep happening. I guess I'm saying why fix something that isn't a common problem. Would you buy custom heavy duty bumpers for your car because you keep driving into things brick walls? Keep in mind the whole point of the EZip is "low cost". But if you keep spending money on repairs and modifications you could have invested bigger money upfront and gotten a higher end bike. LOL, look who's talking......I could have bought a good motor cycle for what I have invested just in my lifepo packs. Hmm, that's right I did buy that motor cycle! All joking aside I have dumped my old Zip (don't actually ride the Zip anymore) and rolled it down the hill with me but never bent or broken the crank arms. But it did bend the crank sprocket which i straightened in the vice. Personally, I'd just fine a cheap set of cranks on EBay for 10 bucks and keep them as a spare just in case. But that's just me cause I don't see having a crake set that costs more then I paid for the bike. Stay safe and upright.........