Fix it or throw it?
 

First time posting, apologies in advance if I don't follow the protocol.

Basically I bought this bike a year ago from a guy on Gumtree, he'd picked it up as a junk bike and fixed it up to sell for charity. I paid $450AUD for it, which I though (and still think) was pretty good value. I'd been searching for 'the one' for a year or so, and was really happy with what I found in this bike. I'm fairly certain it's either a 1984 or 1985 Peugeot PGN10. I use it mainly as a commuter bike about three times a week and have been doing my best to take care of it.

Trouble is he'd put in one of those seat posts that tightens by expanding inside the seat tube, and it seems like it may have overtightened. I brought it in to my local bike ship because I noticed a few lumps in the steal near the saddle, they didn't seem to think these were that significant, but did point out a stress point at the point where the bottom of the seat post sits in the tube (hard to explain, I tried to upload a picture but couldn't). They recommend I get a further opinion from a welder.

Trouble is the welders they'd recommended no longer work on bikes, and I've had a hard time finding someone that still does it where I live. Eventually found someone a good 2 hour drive away; they gave me the following quote:

- $160AUD for "an American made 4130 plain gauge CroMo tube"
- Re-paint anywhere from $200-400AUD

After seeing some pictures he more or less said I could wing it, and just give riding until/if it develops into a crack. In which case he advised that I could get a similar bike for the same price it would cost to repair anyway. I absolutely agree with him on that, but am struggling to get past my sentimental attachment to my bike.

I suppose I'd also like to know whether the 4130 tube would be equivalent to the Reynolds 501 (3 tubes renforcées) that is currently there. And whether a repaint is as good an option as powdercoat (which my local bike shop recommended). I'm a bit of rookie with this kind of stuff, and am struggling to get an idea of what these things are worth. I'm leaning towards having it fixed of course, I just need someone to tell me yes or no either way.

Please be that someone!

If the saddle is at the proper height for you, then I would just ride the bike until a problem develops, if as and when. If you need to adjust the height and there appears to be a problem, then decide. Can't help you with the metallurgical properties of the tubings mentioned. Is the person who gave you the quote a real framebuilder, or "just" another welder? Good luck, but I'd prepare to be disappointed if the tube gives out.

Without pictures, we're just guessing. That being said, unless the bumps are extreme, I doubt you will ever have any cracking problems, or if you do, it will be after thousands and thousands of kilometers.

If it does crack, I doubt the frame is worth repairing. Very few bikes, unless they're extremely rare / valuable, or have sentimental value will ever come close to recouping the costs of a decent frame repair / repaint.

If the bike has a traditional seat binder bolt and someone just used a quill post because that is what they had, you could always try a longer traditional seat post that will go in bellow the stress point .

any pics ?

@danielbh - Bummer! I would figure out how to make it ride worthy without inducing more damage. You do use it for commuting so it has utility as well as sentimental value.

WRT 4130 vs 501 - I will let others comment. To replace the ST would be a challenge with loss of paint around the bottom bracket and seat lug and stays. Don't know if your model has Chrome or not. If so, it just adds to the work. Not worth the effort in my estimation.
Paint vs PC - Paint in the US is more money to apply than PC. The PC results are dependent on the quality of application. Often the details are buried in the thickness of the powder and final state. Yes it is durable but not the same quality as wet paint. Then there is the issue of decals.......

Thanks for all your advice guys, it is much appreciated. I brought it in to another bike shop to ask about the longer seat post solution, but he pointed out that my bike can only take the quill seat posts because there is nowhere to tighten at the top of the tube.

I've been trying to upload a picture all week before eventually contacted an admin, but I got told I can't because I haven't reached ten posts yet (can't post URL to other website with pics either). So all I can do is describe. It's basically a bulge in the tube that covers the area where the seat post is. Consensus seems to be to keep riding until problem gets serious, then chuck it. I'm lacking other solutions and the repair cost does seem expensive, so it seems like I'll go with it.

Thanks again for all your help!

As a final question, are there any other types of bikes you'd recommend? I like the aesthetic of 80s road bikes, happy with not the best quality, just something that can take the daily commute for years to come.