can i use a 700x23 tube for a 700x32 tire?
 

well? will it work?

It should. I've used my 700x23-25c tubes in 700x32 tires.

I wouldn't try using a 700x20-23c tube though.

Yes, but depending on the tube, you may be stretching it pretty thin making it more likely to flat. Some 23 tubes are pretty small to start and it woud be a big stretch. Others are sized a bit larger, and would give you more of a fighting chance.

I've used the same tube for a 700 x 23 and all the way up to a 700 x 38 and it worked fine.

As others have said, works fine. Not optimal and I've only used it in a emergency, but it works. I think it stretches the rubber too thin and you're leaving yourself more likely to have a flat.

Regular tube will work OK, ones marketed "thin" or "light" will do in a pinch but will flat much easier. Rubber stretches too thin.

Ride Safe

SF