Bicycle Mechanics - Is this frame junk?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
markdel
04-23-11, 02:11 PM
Trying to decide the fate of my 79 Peugeot OU10. Bought it in high school and it had been sitting in my parents basement for about 20 years until I brought it home as a winter project. Now it's April and I'm just getting a good look at it. I was going to clean it up to use as a beater/rain bike, but it's got some serious issues from when another family member used it as transportation for a while.
I noticed this bend on the RR seatstay (shown on the left here because it's hanging from the ceiling.
http://i280.photobucket.com/albums/kk171/fredfoomer/bentstay.jpg
Also, the handlebars are bent (twisted about 15 degrees on the right side, and possibly the stem too.
Junk? I know I can replace the bars and stem, though finding French parts might be a pain. I just don't want to get deep into it and find out there are other issues too.
Is there a lot of surface rust? Is there rust inside the frame? Any cracks?
The bend in the seatstay is probably harmless, assuming it doesn't effect wheel alignment. It's steel, so you could bend it back.
If you keep it, I'd replace the Mafac brakes with some modern sidepulls.
The dent doesn't bother me much, and handlebars could certainly be straightened, but the rear wheel seems to be off center in the stays. That usually means an offset rear triangle, usually from a collision. If so the bike will never ride well, though it might pass for a city/beater if it isn't too bad.
I'd pump the tires, straighten the bars and see how it rides. If it's acceptable, I'd be willing to replace dry rotted tires if necessary, and replace cables and brake shoes as needed, but wouldn't put more than that into it. There are many more modern, better used bikes out there at great prices, so keep a tight lid on what you put into this relic (if anything).
w98seeng
04-23-11, 03:07 PM
I'm not too sure about bike tubing, but I do know that once a metal tube has a kink in it, it is never as strong as original. I also know that the kink will get bigger until it fails. I would measure the kink holding a ruler across the bend and using something to measure from the bottom of the ruler to the bend. Ride the bike and remeasure, see if the bend gets bigger.
Something like this...
199079
Ian
The frame on this bike is a "mild" steel and very ductile. There's no need to worry about this dent forming cracks and failing anytime soon, unless it gets seriously heavy use.
Also the brakes, are fine and will outperform most modern sidepulls with this reach. Your key issue is whether it's aligned, or if the rear triangle is pushed over. Besides riding it, you can do a quick test using the string method.
Stretch a length of string from the right dropout around the head tube and back to the left, trapping it under the rear axle QR or nuts. It must have enough tension to be reliably straight. Now measure straight across to the seat tube where it passes. That should be equal within a millimeter or two on both sides.
If it passes, there's a good chance you could have yourself a decent beater for a few dollars invested. If it doesn't, give it to one of those charities that scavenge parts of clunkers and build cheap used bikes form what otherwise would be scrap.
markdel
04-23-11, 06:57 PM
Thanks everyone. I'll so some measuring and see if the rear triangle is out of line. I know there was no collision, but I believe the handlebar damage was because someone hit the bike when backing up. Maybe that twisted the frame in some way. I've ridden the bike for a couple of miles and other than having to adjust the front derailleur it still rode well. In fact my ride on the old girl was what convinced me to ditch my flat bar bike for drop bars this season.
Given its age, you may want to discuss over on the C&V forum. Lots of old school frenchie bike lovers over there.
Those Mafac brakes are good with KoolStop pads. No need to swap them out.
Powered by vBulletin® Version 4.1.12 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.