Looking to buy mtn bike

btb103

I had my much adored mountain bike, an 01' Specialized Hard Rock Sport, stolen after 4 years of trusty service. When I moved here for school last fall I wasn't ready for the perils of leaving your shiny bike locked up with a cheap chain lock. It was gone within a month...

I replaced it with a 1980's Raleigh Olympian road bike, which was a good deal and in remarkably good shape. I enjoyed the bike for a month or so when it was vandalized by a would-be thief (who couldn't compromise my new u-lock). The wheel was bent out of shape (irreparably) and I decided to postpone replacing it until this spring, I left it locked up under an overhang on campus and figured the moisture wouldn't get too it too much, sadly I was wrong, the whole thing was rusted over badly. Last week I bought a new wheel, $70 USED, for my $100 bike. I decided to return the wheel when my dad offered to help pay for a new bike.

I'm now looking to replace it with a mountain bike because I simply find them more comfortable and fun to ride. Something like my old Hard Rock Sport would be ideal. I have a maximum price of about $300 (including tax, accessories, etc.). I've been looking around on craigslist and e-bay but haven't found anything quite yet... my biggest problem is finding a frame that fits me because I am 6'4". My first question is, do mountain bike sizes run the same as road bikes, meaning, will I need a 25-26" bike to fit me - I know the geometries are fairly different in some cases. Secondly, are there any bikes within my price range that I could buy new? Finally, any general information websites or threads about mountain bikes would be really helpful as I don't know too much (just that I loved my old Specialized ) I appreciate the help!