So I am looking at a cross bike for a winter / wet spring bike. Mostly because I can put a rack on it to carry enough stuff to deal with the ever variable weather here in the northwest and run a little beefier tire to deal with the extra crap on the road this time of the year. I can not put a rack, or wider tires on my current road bike.

The cross bike is a Lemond Prorad 08. It comes with a double.. Bontrager Race Cross 46/38 GXP. The rear cassette is a 12/27 10 speed. My current bike has a triple 52/42/30 and a 12/27 9 speed. I ride a lot of steep hills.

So what I am trying to get my head around is how much low gearing I would be loosing on the new bike. Would the lowest gear on the new bike be the same as say the 2nd lowest gear on the old bike or would it end up being higer than that. I need to figre this out so I know if I will need to convert this bike to a triple to meet my needs. Any nifty formulas or advice to quickly figure this out would be appreciated.