Bicycle repair & upgrade

[gillstone]

I picked up an older bike for my wife at a bike swap.  Its a 1986 Peugeot City Express that has been modified to look more like a mountain bike with wide tires and a flat bar. 

She'd like it to be more like a commuter/comfort bike it was meant to be.  In addition, it needs at least one new chainring, a new cassette, and to be thoroughly cleaned and reconditioned.

I could use a general guide to help me figure out some of the bigger pieces like replacing parts of the drivetrain.

What are the best online and offline resources for this?

[DagobertDuck]

Sheldonbrown.com
Parktool.com

[spokey doke]

Have she ridden the bike much yet?

Has she ridden many kinds of bikes much?

If not, I'd recommend a decent amount of trial time before investing in conversions so the decision is well informed (and btw, on many views, a commuter bike and a comfort bike are in two different directions from what it sounds like you have).

Good idea to do some homework, but that might not be sufficient without some road miles...

[GuitarStv]

It's a bike from 1986, which means old components and heavy weight.  It might be best to bring the bike into a bike shop and ask a few questions . . . Does it even use a cassette, or is it a freewheel?  Are the chain rings removable, or do you need to replace the whole crank set?  What size of crank set will fit the bottom bracket?  Those would be my initial questions.

[gillstone]

I love the internet.  A little Googling found the original catalog for that year including a spec sheet for the bike and its components.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CC8QFjAA&url=http%3A%2F%2Fcyclespeugeot.com%2FPDFs%2F1986pdf.pdf&ei=esU_VfCZEdOYyATiloDoDg&usg=AFQjCNHl-ZgSts8yzg58cCJ_ZMIBQFy2eA&bvm=bv.91665533,d.aWw

This confirms how much modification has gone on to make it more like a mountain bike.  Only the style of brakes have remained the same.  The handlebars, stem, seat, rims, type of tires, and every piece of the drivetrain has been modified.

It looks like it should be doable to bring it back as a comfort bike.

[nereo]

my question:  given the extensive modification the bike has already undergone, why not look for another commuter bike and keep this one how it's already set up?  I see decent commuter bikes all the time on craigslist for under $100.  Seems like you'd need to do a lot of work to change it to how she wants it.