The thing that scares me about DIY ebikes is the batteries; mine are stored in an ammo can outside my house and are charged in the middle of the yard. I suspect that the battery suppliers who resell Chinese batteries, have little idea what they're getting quality-wise, and little to no recourse (IMO). I've already had two discrepant batteries (both Headway AFAIK); my "good" battery stayed warm after the last charge, so is relegated to the can. ES has two battery fire stories today. The OEM companies have a lot more to lose and I trust their products.