As a project, I'm building a simple single-speed mountain bike from parts purchased on ebay; I bought a cheap new unpainted 20" MB frame that was advertised as manufacurer overstock. So far so good. I plan to use the bike for city riding and so don't need a suspension fork. Instead I bought what was described as a suspension corrected rigid MB fork with a 7.5 inch steerer tube (the longest I saw for a rigid fork). Before I even began to tackle the headset, though, I noticed that the steerer tube is barely longer (just a few mm) than the headtube; no room at all for a headset or stem. Is it possible that I bought a weird frame? (I never considered the length of the headtube an issue.) I looked at cheap suspension forks and the longest steerer tube I saw was 8 3/8 inches, but I doubt even that would be long enough. What am I missing? Thanks in advance.