Bicycle Mechanics - 5 speed conversion?

Hi There - I just bought an older Ross Europa ten speed for $60 on craigslist in NYC. I'm a newbie at working on a bike so I really appreciate any advice/expertise you might have.

I don't like the paint on the bike(color and condition), so I've taken the ENTIRE bike apart to sand it to the metal and repaint. Now I've decided it's also a good opportunity to degrease/clean all bearings and regrease before painting, since the original grease is rock hard.
My Main issue is this - I live in Manhattan and quickly found that ten speed travel is not a practical way for me to get around town.. so I've decided to convert it to a 5 speed. My question is: Can I do this by simply removing the 2nd larger/outside chainring(leaving one smaller chainring which is already attached to the pedal axel, and is 6 1/2 " diameter), and continue to use the original rear cassette/cluster and original rear derailleur. The rear wheel has a 5 sprocket cluster. My idea is to run a cable back from a new single 5 speed controller. I guess I'll have to shorten the chain and remove the front derailer as well.
Not sure if this factors in but my wheels are 26 ". Will this work, or do I need a more appropriate derailleur? Thanks for helping!

Alex

The back derailer will function normally without a front one.

so my entire plan should work? will it still shift smoothly into all five gears with one chainring pulling?

your plan should work, and shortening your chain shoudn't be necessary.

here's the caviat: the bolts holding your chainrings on may be too long when only one ring is attached. if your bolts are made to go through both chainrings together, this will probably be the case. not a huge problem, just get shorter bolts. this is standard practice for creating a fixed gear using a 10 speed crankset.

nice! the larger chainring was attached to the smaller one with bolts going through both. I took that off - and I'm left with smaller one "built in" to the one piece crank set.. yeah, it's one of those.

But that's great news, I'm excited about this conversion! My main concern was the rear derailer moving the chain up and down 5 sprocket cassette on rear wheel without a second ring on the crankset - but I'm just understanding now - that's the job of the derailer!

Thanks a million.

OR, as I recently read on another thread "derailers are dumb, they just do whatever the shifter tells them to do."