Branson knows better then myself. The 175 is more beef, the 160 has got some frame differences that work for me but either I think will suit you. I think Branson told me the frame tube has thicker walls on the 175.
The CL175 has so ever so very slight increases in some of the tube diameters. The backbone is a hair larger and a couple other tubes...by my measurements it seems to be around 1/10th inch or so on the backbone.
I'd be very curious to see a couple of stripped 160/CL frames weighed to find any hidden differences in beef.
I think my bike has a CL frame and Mary's a 160. Certainly haven't found any differences that you'd notice without a micrometer. Some of the tabs are a bit different. The rear brake cable setup on the 160 kicks ass compared to the stay rod setup on the CL. Just plain looks better and is easier to setup a rear brake pedal.
I noticed the rear mount for the gas tank was different and the rear brake was different. It seems the head tube was slightly different length too but I could be wrong there. Just wondering what people found who've been down this path already.
JohnnyB- If you have one of those block off plates I'd like to order one. No rush.
Evil- the work address would be just fine