On a 4km commute you could ride just about anything.
heck, at 4km he could run to work! or even skateboard or lollerblade.
i think it really comes down to your commute route and whether you want to use this rig for other duties.
personally i'd do an old-school steel hardtail that'll take bigger hoops, sloping tt, carbon fork, disc and run a flat bar.
a stiffe set up like this would be a sweet commuter ripper.
or get this and save some cash!
http://vancouver.en.craigslist.ca/van/bik/4265556260.html
big reason i suggest a mtn bike set-up is maneuverability esp if you're riding downtown.
We don't know what our limits are, so to start something with the idea of being limited actually ends up limiting us.
Ellen Langer
