Bicycle Mechanics - I need help picking a front derailleur

Hello,
Don't laugh at me because I am still a bicycle noob, but I need help selecting a proper front derailleur. I was transferring components to a different frame and broke the clamp on the old derailleur. Since it was old and crappy I decided to buy another one. My bike is very entry level road bike, but it has Shimano 105 components on it. I have been looking at Shimano Ultegra, but its description says that I need a 10 speed setup, but I only have 7 speeds. What would be your recommendation for a derailleur in $40-50 range?

Crackset is 53/39.
Seat tube 34.9mm. It must be clamp-on, there is no braze-on notch.
Back wheel has 7 stars.

Thanks in advance.

Setup:

http://img0.uploadhouse.com/fileuploads/3927/392732045c1673ac23e4d5e8ce2a29a51340aec.jpg

You need a clamp-on front derailleur with the correct clamp size to fit your seat tube.
The FD needs to be designed for a 7-speed or 8-speed drive-train with a double crank. A 9-speed FD might work but 7 or 8 would be better. You could run an 8-speed chain.

Al

The stops on the FD will allow any FD that works on doubles - just about any - to work just fine without throwing the chain off the chainrings. All this "10spd FD" is ridiculous. This just means it has the range to cover this sort of distance that a 10spd cassette requires. Not that it has to.

There's really no point in looking at Ultegra or DA (in fact, avoid DA - some of the older stuff doesn't work with yours) unless you get a real deal. 105 is quite good enough; for that matter, so is Tiagra. If the prospective unit is otherwise qualified, consider buying used. It's hard to wear out an FD.

Thanks for suggestions. I have been looking around on Ebay for Tiagra models.

Is it possible to fit a 31.8mm clamp on 34.9mm seat tube?

Or should I buy a braze-to-clamp adapter?

Buy the size you need. If you can find an adapter in the right size, that is an alternative.

If you get the wrong size clamp, you should be able to swap it out at the LBS.

The stops on the FD will allow any FD that works on doubles - just about any - to work just fine without throwing the chain off the chainrings. All this "10spd FD" is ridiculous. This just means it has the range to cover this sort of distance that a 10spd cassette requires. Not that it has to.

Can't agree with that. 10-speed front derailleurs are much narrower than those designed to work with a 7, or 8-speed chain. It might work but would require a lot more trimming than a wider FD. Has nothing to do with "range".

I've got a 105 (double) front derailleur that has had little, if any use. It's a 5500 so I assume that means 9-speed. It's a braze on but I also have a 35.0 braze-on adapter clamp. I'd be willing to trade both for just about any bike stuff that you thought was equal.

PM me if you're interested.