My adventure into the world of motorized bicycles originally started when the derailler and gearing system on my mountain bike fell off and got destroyed. Since I could no longer practically use the bike for mountain biking or biking around hilly California, I wanted to find a way to bring new life to the bike and avoid tossing it out. That's how I found out about MBs.
Which brings me to my problem now. Since I don't have any sort of tensioning, and since my bike frame has a vertical drop-out, converting my bike to just run as a single-speed hasn't worked out so well. Just the other day, my chain fell off and got gnarled because of my inadequate single-speed conversion. So since then I've been having to push the bike in order to start it.
What I need is a chain tensioner, but not something ridiculously expensive. I thought I'd share this thread from mtbr.com about DIY tensioners.
All I know now is that I'm definitely going to build one of these!