Hi Folks...

I did the "String" test on my used frame today and the drive side is out (assuming the non-drive side is correct) by 9mm when measured from the string to the seat tube.

String Test:
https://www.sheldonbrown.com/frame-spacing.html

Should I even worry about the 3/8in difference? This is just going to be a beater single speed to ride to the store, bars, etc...

Thanks.

Never assume anything... hoping your frame is steel as aluminium frames do not like to be corrected.

The side to side measurements need to be equal and the dropout spacing needs to be correct in order for the bike to track properly.. this will improve your riding experience.

You also need to check the dropout spacing to see where it is at as if the drive side is out by 9mm the dropout spacing will also be off.

If bringing the drive side out by 9mm centers the rear triangle and corrects the dropout spacing you have it easy... if the dropout spacing becomes excessive then both sides will need to be adjusted to set the dropout spacing correctly. This would be done by bringing each side in by half the distance needed to correct the dropout spacing which will keep things centered.

Aligning the dropouts would also be prudent.

First thing that i'd do is verify that what you're measuring is accurate. Or take it to a shop with the real tool.

9mm is hugely out.

The dropout spacing looks to be ok for a bike that had a 6 speed cassette (126mm). I'm replacing it with a much narrower single speed wheel so if I bring the side that is out, back in and re-align the drops I should be ok.

I'm going to attempt to do it myself since the frame was 20 bucks and no shop around here will touch it for less than 40. If I'm into this frame for 60 I'd rather throw in another 40 and buy a better (used) frameset.

Try selling your bent frame to this guy.
This will allow him to build a bike that is totally FUBAR.

Bontrager Select Track wheel issues... Help me please.