Chain Tension, old peugeot

[mcdonaac]

hey,
i picked up an old peugeot racer the other day second hand, looks to be very old, not sure what type. Iv started updating parts, and i bought new 700 wheels to fit it, they were very tight and i had to force them in, but they fit. iv also removed the gears and put in a single speed cog, but i cant get the chain to tense.
the wheel when put back completely in the horizontal brackets, leaves the wheel completely crooked, aligning right, so i have to put it half way up one bracket and fully back on the other bracket, but this leaves the chain untensed, what can i do to fix this?

the wheel is perfect and new by the way. and the frame wasn't bent out of shape in any way when i put the wheel in.

[DaveM]

A couple things could be going on. A couple questions:
1. If you pull the wheel all the way back in to the dropouts, is the rim not centered both down by the bottom bracket and up by the rear brake?

2. Do the dropouts look pretty identical? Sometimes the right side won't have as deep a slot as the left.

3. When you say the wheels were "tight", what do you mean? Is it that the axle was a bit too long and you had to kind of stretch the frame open wider to get it to pop in?

It could be that the frame's rear triangle is actually bent to one side a little. The good news is that that's usually fixable pretty easily.

If the wheel is brand new, it should be "dished" correctly (meaning the rim is centered over the axle). But if anyone played with the axle spacers, that could be off.

If you have a good ruler, measure the space between the two dropouts in the rear (not including the dropout, just the space).

Finally, note that the axle does not need to be all the way back in the dropout. Is has to be far enough that the axle nuts or QR skewer get plenty of metal to grab on to. But on a single speed, you usually shorten the chain enough so that you can get tension on the chain without pulling the axle all the way back.

(pictures would help too

[Joe_W]

On old road bikes:
- the rear dropout spacing is usually less than the 130mm of today. You can widen the rear triangle (look at Sheldon Brown's homepage: http://www.sheldonbrown.com), if it is a steel frame. Then you can fit in a modern wheel.
- Then, the dérailleur hanger has to be straightened (look at tutorial on this site). (not a problem when running single speed).
- The rear dropouts on old steel road bikes were usually a bit out of alignment. There were screws installed to set the point where the rear wheel would sit.
- maybe you have to shorten the chain, maybe you have to install a half link.
- also: pic please (just curious)