Hey folks, 6'2" 245 Portlander here. I picked up a 26" 21-speed Magna Silver Canyon on CraigsList a while back and I'm looking to get it modified for a regular commute to work (obviously something I'm going to have to build up to). The components all look stock at the moment and my first change is going to be to slicks. I'm thinking of the Schwalbe Marathon Supremes as the area I would be riding through has a lot of construction (nails and staples), partying kids (broken glass), and thorn bushes. It will be all on road, so I'm not worried about the off-road traction capabilities, I just don't want to have to mess with flats if I don't need to. I had it suggested to me that I also change the gears, the seat, and pad the handlebars. I already know how to size a seat properly and can figure out the handlebar padding, so my only concern really is the gears. What are people's thoughts on this? Any suggested manufacturers? The commute would end up being 12 miles both ways over some moderate inclines, but nothing major. Any advice is greatly appreciated.