... how much rust is too much rust?

[keyboardmonkey]

I've recently returned to cycle touring after a few years' layoff. I now have a light tourer/Audax bike with an aluminium frame. However, I still can’t help wondering whether it is worth trying to restore my old steel (and rust) framed bike. The chap in the shop I bought it from was horrified that I was still riding it with this amout of corrosion on the frame. I fitted a new rear derailleur and a few other bits for a short tour before I got the new bike. Is my old one worth any more expense, or should I finally lay it to rest?

[thirdcrank]

Rust has no structural strength. Try cleaning it back to bare metal. I think a certain amount of rust can be common on the chainstays by the rims, but that at the bottom of the down tube looks a bit ominous to me. Remember that if a frame has not been treated internally, it can rust from the inside and you don't know till quite late in the day. shake the frame to se if it rattles. Ping the tubes. Try to see if rust can be shaken out when the stem and seat pin are removed.

[keyboardmonkey]

Thanks, Third Crank. I think I might keep the frame oiled then strip it down during the summer as a bit of a project.

[531colin]

I have a 531 frame more than 40 years old. It now flexes too much to carry touring luggage. I think that must be internal corrosion. I dont ride it far from home! Before you spend money on your old frame, check the rear dropout width, to see if it will take modern wheels.

[saudidave]

It looks grim but I suspect that it is just surface rust pushing the paint off. Strip the paint off and see how much pitting there is. It takes for ever for the structural strength of a frame to be jeopardized by rust. Of course the chap in the shop was horrified -he wants to pray on your fear so you will buy a new bike

[keyboardmonkey]

Of course the chap in the shop was horrified -he wants to pray on your fear so you will buy a new bike

Now, now, saudidave (although I did buy my new bike elsewhere). I hope you're right about the rust only being a surface problem, although I won't risk scraping any more off until the summer when I'll have time to work on it almost daily, and in good weather. Cheers.

[PBA]

All good advice so far.

Rust is about five times the size of the steel used to make it. So a little steel loss can produce a lot of rusting.

If you are not touching this for some time oil or phosphating would be appropriate if you think it's condition is going to get worse between now and summer. In the absence of water corrosion will be effectively nil so keep it dry.

When you do scrape off the rust you will be looking for any loss of material thickness. If this is observable in any of the higher stressed areas - bottom bracket and head tube spring to mind then you need to proceed with caution - if at all.

Remember that while the tubes will be quite thin, they are likely to be thicker at the joins.

Also remember that if you build up the bike with a rusty frame you can "swap" in a new frame later but if you don't use the rusty frame you just don't have that essential second bike...

[keyboardmonkey]

Thanks for that, PBA. Sorry, colin531, that I somehow missed your comment. My 531ST frame is nearly a quarter of a century old, and (apart from the rear derailleur, 7 speed cassette and chain) the most recent parts are early-mid 90s kit. The hubs are Deore DX and the rims are decent Mavic ones.

So if the frame doesn't collapse underneath me I hope to reuse what components I have after a bit of tlc and greasing etc (I'm putting back the old silver Deore rear derailleur now it's fixed).

I've hardly used the bike for ten years. In October I fancied a bit of a bike ride so I went around the Yorkshire Moors and Dales - about 300 miles in five days (not including the enforced rest day - I was shattered after two days of cycling). I'm hopeful there are some more miles in it yet. Thanks again - Chris.

[Freddie]

Get it shot blasted, some old 'un I know who does a lot of resprays on older frames only has them shot blasted, as he says if they're too weak to be ridden the shots will tell (pierce holes, perhaps...).

[Russell160]

I would second the shot blasting option, you can get it done for a £10 or so in most places. Yours looks pretty grim but so did mine and after a blast mine came up nice and clean. You could ask them to give it a blast in and around the bottom bracket area and see what happens. I see you are in Yorkshire: you could take it to Elliss Briggs in Shipley who are a proper bike shop with frame building expertise, they will give you an expert opinion on its basic condition. They also know a very good powder coaters also in shipley or bingley whose name escapes me. Another thing: there is a product called JP Weigle Framesaver available from a firm called Ceeway Framebuilders. This is basically an underseal that you can spray inside that will at least arrest rust. Personally, I have found it's easy to end up spending quite a lot of cash on an old frame and bike and you end up thinking: ooh, I could have got a new one for that. On the other hand, there is a curious satisfaction in making something last...

[asterix]

I have a 531 frame more than 40 years old. It now flexes too much to carry touring luggage. I think that must be internal corrosion. I dont ride it far from home! Before you spend money on your old frame, check the rear dropout width, to see if it will take modern wheels.

531 does flex rather a lot for touring IME. 531 ST is a better bet or maybe oversized 531. I have had all 3 and prefer the latter 2. The 531st is 1987 vintage and completely clean internally. Older frames can be cold set to spread the drop out width (see Sheldon Brown R.I.P.) without harming the frame (been there, done that).

[531colin]

Flex in my 40 year old frame has come on and gradually got worse. It was stiff when new, even with the original 531DB. It has cast lugs and oversize seatstays, which I think were from a tubeset for tandem or sprint use at the time. Back end is now 135mm. When something finally breaks, only full military honours will do! Ridiculous how we get attached to the things!

[keyboardmonkey]

Thanks for the advice, folks. I didn't imagine shot blasting would be so cheap. If I can't find anywhere nearer I'll probably get in touch with Ellis Briggs shortly. Cheers.

[keyboardmonkey]

Crikey. I asked for advice about this almost a decade ago. Somehow I didn’t post an update until prompted by another thread. Still going strong, pictured last month:

Thanks again to all those who offered their encouragement.

[[XAP]Bob]

Too much rust is only a problem in that it can hold water etc and promote more rust. The actual problem is not enough steel left