Cassette Questions
 

I'm deciding on what size of cassette to get for my new wheelset. I'm thinking of getting a 12-25 (9 speed) because that's what my old wheel has on it and it's fine for me, but maybe I should change it. What size of cassette do you use and why? Also, my chainrings are 36 and 48 which give me a lot of overlap gears. Why not just have a single chainring and use a cassette with greater variety of gears? It seams to me you could get most gears you need with a single chainring...
Thanks,
Hjeand

What kind of riding do you do? I'm under the assumption that Minnesota is pretty flat, therefore, I'd consider running an 11-23 cassette seeing how your chainrings are smaller than a compact.

1. if you ride with a group, especially in a paceline, then close cog spacing allows you to easily maintain your prefered cadence while riding at the group speed
2. if you ride in the mountains, choose gearing that allows you to climb the worst that you encounter regularly
3. if you like speed (and have the fitness to get there), then you should think about a small cog to go along with your smaller than normal chainrings

If most of your riding is on the flats. Considering your chainrings (48-36), I would go with an 11-21 (11-12-13-14-15-16-17-19-21). With that combination you gain the 11 and 16 tooth cogs. Your lowest gear of 36/21 would give you the equivalent of a standard 39/23. With that smallish big ring (48) you will need the 11 cog. The 48/11 is the approx equivalent of a standard 53/12.

+1, with a 48 chainring, I think you will run out gearing around 30 to 35 mph, I rode a bike with 50x12 on sat and ran out at 38 mph.

you can, and thats what many cyclocrossers do... however, the chainline would be more angled, accelerating wear and increase chances of skipping/misshifting gears