Singlespeed & Fixed Gear - Removing the front derailleur from a bike...

I recently aquired an old fuji something or other with downtube shifters. It's crap, so i'm thinking of setting it up as a dedicated bike for my trainer. My gf rides the same size bike as i do (which happens to be the size of the fuji), so it'll work out nicely.
Since we both ride fg primarily (with 165mm cranks), i was thinking of replacing the cranks on the fuji. Then i realized that instead of going crazy looking for 165mm road cranks only to settle for 170 (or, more likely, 172.5), i could simply remove the front derailleur/chanrings/crank/bb that're in place and replace them with an old 165 sugino ___ (i forget), ___ bottom bracket i have laying around, some random chainring and keep the rear derailleur/cassette for switching to different intensities during intervals.
Is this feasible? Is there anything i have to keep in mind when approaching something like this? I can't think of any reasons why this won't work, but then again i'm not a mechanic and am still a bit lost when it comes to anything other than basic derailleur adjustments.

thx.

This will work fine. I really like set ups with only a rear derailleur as they make for great commuters and still give a wide range of gears with about 1/2 the trouble of a dual derailleur set-up. Sounds like a great idea-- good luck!

A word about alignment: Aim to have your front chainring in line with your center rear sprocket as this will help prevent chain throw at the highest and lowest gears. Make sure to double check chain length with the new crankset installed (not to much tension in lower gears and only a marginal amount of slack in higher gears).

ah, good tip. thanks!

yeah, i second the 1x(x) style of shiftables as well.
As well as centering the chainring with the middle cog. Also, now would be a goood time to learn how to set the limit screws on your RD!

A lot of people use up to a 1x10 setup for cross. durable, less likely to drop the chain. one shifter is twice as good as gaving two.

no problems there at all. did the same thing with a bridgestone mb3 i set up as a commuter. removed the inner ring (replaced the chainring bolts to do so) and the front der and had a nice friction shift 5-speed set-up. dropped the chain once in a blue moon and considered a dh-tyype tensioner to deal with that, but it was never enough of an issue to follow thorugh