Looking for a little upgrade to my existing old bike. Looking for a mountain bike or hybrid (not a no-gear cruiser or fixie) bike with at least 18 gears, good front and rear brakes, and a frame/seat that would fit my 6'1" height. It's the end of the school year so cheap bikes abound. I'm offering $90 for a bike, or $100 if it includes a U-lock. Thanks!