Originally Posted by
dminor
When you are right on the cusp of sizes, the rule of thumb is to choose by the use. If this is going to be for aggressive trail riding or freeride type of riding, go with the medium; it allows you to ride centerd in the cockpit which suits that style of riding. If this is a bike more for just trail riding / XC-ish riding, go with the large.
You didn't mention the purpose of this hardtail build but that will give you a general guideline. For instance, I'm 6'-1" and I race downhill on medium frames. But I would never own a medium for a trail/XC bike; it would just be too cramped.
I honestly don't even understand what "xc" means, really. In my mind xc was just "not these new-fangled freeride, dirtjumping or downhill things" but reading around I've seen people describe lots of singletrack riding as being more like "trail riding" than "xc" and I just don't get it. The impression I've got is xc kind of means "lite" mountainbiking anymore, and sitting on that bigger frame sitting all upright I just couldn't imagine how I could ride through a stream or a ditch or something like that on it.
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