Reuse oversized hardtrail frame to build a commuter bike? I have a spare hardtrail frame which is too big (20.5") for me (5'7") for riding trails. Would it make sense to build a commuter bike for me as road/touring bike frames are generally larger than MTB? Could it be comfortable to ride this frame on road? I like to lean forward on a bike and I'm a fast type of commuter.
It's a good, cheap way to build a first commuter. Throw on a pair of road slicks and lights and go to work. It will give you a chance to decide what you really want in a commuter bike. It will be able to handle bad roads and pot holes better than a road racing bike. But, it will still be heavier and slower than a bike based on a cyclocross/utility/road frame with 700c wheels.