Seized and shredded bottom bracket

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  • Not a shred of aluminium left! Nor much paint to speak of. But I'll be repainting... I'll put a link here to the project thread once I start it.

    That only took what... three months? It was about two weeks once I started with the caustic. At some point I learned that you can just put a crap load of caustic in the ice cream tub and leave it for two days, then change the solution out, repeat, voila. Low faff, like watering a hazardous pot plant.


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  • Tried to strip paint today using Starchem Synstrip. Goodbye to the remaining paint!

    I'd managed to salvage the 653 fork decals for the new paint job, but not the frame decal.

  • I applied it first to forks and main tubes with a brush, covered in cling film and then came back 30 minutes later to try and rub/sand off. Not much joy, got about 2% of the paint off. So I thought I'd try sanding. This revealed the original decals in a cool blue sparkle colour.

    Unfortunately it also revealed a crack. I thought this was just surface rust originally when I bought the bike. But it goes right through the chainstay. It's about 10mm long.

    Toothbrush bristles go through it, so it's definitely cracked the whole way through the tube. It's the location where the tyre on the old build must have rubbed, to removing paint and exposing wearing down the steel. Then I guess time and oxygen did the rest.

    Anyone here know if this is repairable? I've never really seen spot repairs on tubes so I suppose it would need a new chainstay. Is that likely to be £££?
    Edit: Looks like Winston Vaz charges £100 to fit a 631 chainstay. Not horrific, but not peanuts either.

    Crazy off-piste idea: I could strip paint, lightly sand that section of chainstay and then wrap with a ribbon of carbon weave soaked in epoxy. I've repaired carbon frames that way. Is that a stupid idea on steel?

    I've also asked on Current Projects chat and miscellany.

  • What a pisser after all the effort put in. £100 for a new stay doesn’t seem too bad but not peanuts as you say. Main problem is that you can’t see the extent of any rot on the inside of the stay.

  • I guess you could file a relief into it and have a bit brazed in where the crack would have been. Adds some tyre clearance as a bonus. Probably look a bit silly just on one side though

  • You can run a weld in to that. It would be unnoticeable when done. I’ve welded up a couple frames with big cracks and still holding up years later.

  • Well that's promising. The chainstays are very thin on 653 frames though, at 0.6mm. What's the thinnest tubing you've achieved this on?

  • Reading through your thread, your dedication is inspiring. I know for sure you're going to save this frame and eventually get to ride it for a long time to make a happy end to this saga. The weld that Dogtemplle suggests seems too good to be true, though I am no expert in this field. Isn't 653 built with 753 rear triangle?

  • Thanks. Yeah I'll save the frame one way or another. Tbh I just enjoy a good faff.

    653 does indeed use the same chainstays as 753, 0.6mm Mn Mo steel:

    Current plan A is the carbon wrap method. I've done it before on carbon bikes and I'm pretty confident that epoxy bonds well to freshly sanded steel. It's something I can do in my own back garden for a cost of £11. Might make the ride a little stiffer? But chainstays are supposed to be really stiff right? I can even wrap both chainstays to keep symmetry. Total weight gain will be like ~50g, no disaster.

    The one downside is that if I resell then the carbon repaired 653 frame would be worth ~£100 less than if I got Winston to fit a fresh seatstay. But by repairing myself I save £90 so it comes out in the wash.

  • I’ve welded 531 at the thinnest and 531 isn’t a good steel to weld, even so I wouldn’t hesitate thinner. You can weld razor blades, the thin aspect isn’t the hard part. It’s getting the metal clean enough and the inside of that tube is likely to be all scabby.

    I’ve welded up my very old vespa which needed lots and lots of welding on the thinnest crappiest steel panels. It is doable it can just be a pain if the metal is poor quality or dirty.

    The good thing here is that it’s a tight crack, you may be able to run a weld over it and close it up without any filler and it will be fine. So long as it’s clean... from what I recall 653 is a good grade for welding too.

    Short of it though is that it is very possible.

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Seized and shredded bottom bracket

Posted by Avatar for Ndeipi @Ndeipi

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