Question.
 

I have a 1970's Motobecane Super Mirage. My question is whether or not there is something for the rear wheel that prevents the non-drive side of the axle from going past the point where the rear wheel is square in the chainstays. I saw on another motobecane there were screws on the dropouts, but mine doesn't have those. Is there an aftermarket piece that accomplishes the same thing? Also, can I use a Nashbar carbon fork and still fit the 27" front wheel and stock u-brake?

Don't know about the wheels, but why someone would want to put a nashbar carbon fork on a super mirage is beyond me.

Though, if you want to do it, you'll probably need the 1 inch threaded fork if you're looking to reuse the stem and bars.

Yes, there were little spacer thingies that were common on road bikes not equipped with alignment screws. I have a few in a box somewhere. I have also seen people use BMX chain adjusters but they look a lil funny unless it's a track bike.
Example:
http://www.zenital.com/images/ANTIX/AP145-010SL.jpg

As far as the carbon fork is concerned......If it does fit your wheel it will be VERY tight and your current caliper may not have the proper reach. But you never know! I'm sure someone can chime in with a mathematical calculation to figure it out. There are quite a bit of variables to consider..... And may I ask why you would want to do that?

Kelly D

Are you sure your axle nuts or quick release are tight enough? That wheel, once centred in the slots, shouldn't move. The adjusting screws, once set up, let you place it quickly, but if you don't have them you should still be able to centre the wheel and clamp it in place with no worry it will shift.

Well, the carbon fork idea came from the fact that I bent the hell out the stock fork trying to break the original stem loose from the fork. Let's just say that didn't end well, but I managed to bend the fork back into usable form, fairly straight actually.
The reason for the cheaters in the chain stays are b/c I'm constantly having to take the rear wheel off to put the bike in the car. Kelly, will those thingys work for the semi-horizontal dropouts? If so, how much do you want for them? The bike isn't a track bike, it's a 5 speed (cassette), the dérailleur has it's own little seating bit, so i only need one for the one side... I think. Would a photo help?

Yes. There are such things. They weren't all that uncommon back in the 70's and 80's. I'll try to find a source for you.

I have several of those dropout stops around. PM me your address, and I'll send you one.

Neal

Neal, PM sent, thanks a ton!