I've been thinking about getting a hold of a cheap frame for restoring/converting to a single speed. I've kept my eye out on the usual sites (ebay, gumtree) but the sellers/buyers there are clearly too savvy and know what people will pay for old beat up bikes, so they're never cheap. I've heard people talking about "tip shops" or "dump shops" on other forums, which I take to mean basically a recy…