I'm looking for the down to earth experienced opinions on this idea. Hence 50+. It may be nonsensical but tell me why if it's too off the wall.
I'm scheming on making a psuedo-single speed starting with a CX frameset. The bikeisland/nashbar variety which can be had for 200-300 dollars. Or an aluminum road frame with cf fork if that's too silly, but it's the longer wheelbase with close to road geometry that attracts me.
In my amateurish fashion I only use one crank ring, almost always with 70-85 gear inches, so why not a single-speed crank? No expensive shifting apparatus, lighter weight, would that throw the chain line off? I'd use the same reasoning on the back and go legitimately single speed but, I may prefer or even require some gearing on these hills, and I'd like my wheels to be compatible between bikes. So I thought to just use my current wheels, at least at first, with the 8-speed cassettes. I'll take a junked derailleur and clamp it off at the gear I want with a cable fragment, no shifter. The DR and cassette will cost about a pound but I'll trade that extra weight for flexibility. I figure the whole bike fairly inexpensively will weigh about 18-19 pounds which is featherweight from my perspective, with room to reduce in the wheels and crank.
What have I overlooked? Later on, when I'm thinking "I wish I'd thought of that, before ever starting"?