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I am considering buying an Alan Super Record aluminium frame, but there is a hairline crack in the lug on the bottom of the headtube. Is this a big problem, and would it be unsafe to ride it?

Is there any easy way to fix it, or it is a sign of a more serious problem? I have no access to welding or advanced repair machinery.

picture of lug with a crack

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    I shouldn't even test ride that thing. It's a write off or decorative piece. Well, I shouldn't buy an Alan bikes in the first place. Industry used horrible Al alloys in those days. Fatigue cracks were common. What is more, since those alloys were also horribly susceptible to heat treatments Alan frames were glued into lugs. I don't trust those glues to age well.
    – gschenk
    May 25 at 10:36

6 Answers 6

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Answering your questions in the wrong order, it isn't a sign of "something more serious", it is though a serious defect in the frame.

At best, the bottom cup will be a loose fit, and the crack will slowly propogate upwards if ridden until the lug is split and the bonding to the headtube is compromised somewhere on the scale from "completely" to "significantly."

It is probably repairable by an experienced aluminium welder. I do not know if these old frames/lugs were heat treated, but if you did go for repair, you would lose alot of the fancy scrollwork, the repair would always be obvious to some extent and the headtube would need reaming back into spec to take headset cups as the heat of welding will distort it as well as the extra material being there to form the repair. It is possible that after a few years, under stress, the repair would fail again, or some of the adjacent material as a result of the heat used for the repair.

I would suggest that it's perfect for "Display Only" but don't feel too downheartened: I've heard from enough people that these ALAN frames are very flexy and not to everyone's taste. They do not have the best reliability reputation either, though many people love them and the price has spiralled up over the last 10 years since I'd considered getting one.

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  • Yes, was assuming that using it will eventually split the lug... Especially considering ALAN was famous for not welding, but screwing-in lugs, could be very dangerous. Thank you for the in-depth explanation!
    – goose_lake
    May 24 at 18:58
  • If you purchased the frame with a fork a thorough examination of the fork would be prudent. What caused the head tube damage may have also damaged the fork.
    – mikes
    May 24 at 19:24
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Questions of "Is X safe?" generally class as Opinions and tend to attract both YES and NO answers.

Ultimately it comes down to your personal risk tolerance and the severity of the consequences. If a head tube failed suddenly while you were riding, you could be mudsucking before realising something was wrong.

Conversely, a torn saddle (for example) has low consequences, perhaps just staining your trousers.


Personally I would not ride that frame - there are plenty more bikes out there, just keep your eyes open.

This would be a high-consequence failure if it let go quickly. If it gave-way slowly you'd hopefully notice and cease riding before complete failure.

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    Thank you! Makes a lot of sense.
    – goose_lake
    May 31 at 15:11
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I lost a nice Ghost All Mountain Range MTB to a similar hairline crack.

While nobody can predict when or if it will break completely, the logical argument is this: there was a reason why the hairline crack appeared in the first place. This reason must, with a chance of 99.999...% be something that is not an individual event, but the systemic and constant wear and tear (material fatigue) caused by frame geometry and the dynamic forces acting at that spot. This material is, after all, not glass, where a single pebble impact can easily create hairline splits.

Assuming that it is so leads to the conclusion that the split will indeed get larger over time - no matter how long it takes. As the split has already weakened the area, it can be further assumed that the rate of growth will be at least as fast as before, maybe faster.

Aside of the technical/objective aspects, there is the statistical thinking - no matter how small the chance that the spot fails during a ride in a catastrophic way: the possible damage to the rider is very high, possibly fatal. Think about going OTB at high speed or in dangerous traffic, or over the side of a steep mountain ledge. So the expectancy value of the damage (probability multiplied by damage) can possibly be very high indeed.

Your conclusion depends on your character and risk aversity. I personally went and bought a much nicer new bike - it was a welcome excuse for that. ;)

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  • Ended up passing on this offer as well, since as you're saying it's potentially very risky.
    – goose_lake
    May 31 at 15:12
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There are several red flags:

  • old Aluminium alloys are often very susceptible to stress crack corrosion

  • old frame that saw many load cycles and is susceptible to fatigue

  • this is a very long crack, it is certainly longer than what is visible

  • cracks grow when loaded, even in modern alloys without fatigue or corrosion promoting it

With those red flags in mind, always assume it will fail next time you ride the bike. On failure the lower headset bearing will be lose and the fork would have no lateral stability. In everyday riding there are frequently conditions where an uncontrolled fall cannot be avoided.

Is that acceptable risk to you?

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I had a similar crack on an Apollo. I used a lathe and old piston to make a tight collar which fit over the bottom then refit the cup. 70 mm x 12 mm by correct ID. Probably not what you're looking for aesthetically, but works fine.

I would not ride without fixing but welding will create more problems and deface the Alan so a sleeve is stronger and covers part of the Alan design at bottom of headtube.

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I have found some information that those Alan frames are screwed and glued together. Probably both at the same time. I doubt heating the lugs with welding would do the glue bond any good.

I'd hang it on a wall.

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