wesnewell
100 GW
The rims on the newer kits are only 21mm compared to 25mm for the older model kits. Max recommended tire size for a 21mm rim is 2.0", although I've put 2.4" Cyclops on them before. Stem length can be made longer with valve stem extensions. That said, I found even the old 25mm rims too narrow for my liking with the 2.4" tires and relaced a 32mm rim onto the hub. The depth of the newer rims is also 1/4" deeper than the older model Champion rims.
http://sheldonbrown.com/tire-sizing.html#width
http://sheldonbrown.com/tire-sizing.html#width