Replace head tube?

[sussex cyclist]

I recently had a steel frame custom built. It turns out the head tube was slightly deformed. (This wasn't discovered until after I'd ridden it around for a bit and had to remove the headset). I sent the frame back and they've reshaped the tube and are satisfied it's now good; however, they've given me the option of completely replacing the tube if I prefer (no charge). I'm trying to decide if major surgery is better avoided for any reason.

[mig]

how are the tubes joined?

[sussex cyclist]

Fillet brazed

[slowster]

I am not sufficiently knowledgeable to advise, but I think it would help to provide more information.

- By deformed do you mean that one or both ends of head tube was slightly ovalised, or something else?

- Did the framebuilder confirm what the cause was? (My limited understanding is that deformation may sometimes occur as a result of the particular circumstances of heat applied during frame manufacture, e.g. I think it might be more likely with TIG welding which heats the head tube unevenly (on the rear facing parts of the tube where down and top tubes are welded, than with a lugged head tube using lower temperature brazing and heat applied all round the lug enclosed tube.) Edit - I see it was fillet brazed, so the heat was on one side of the tube, but I think brazing with brass solder would be at lower temperature than TIG welding.

- What tubing is it? I presume it would be easier to use tools to correct the deformation with a non-heat treated alloy like Reynolds 520/525 and 631, as opposed to 725 and 853.

[sussex cyclist]

It's Reynolds 853.

There was a distortion towards the back of the head tube, thought to be caused by heating and cooling during the brazing process.

[Barrowman]

I used to ride with a professional welder who built his own frame and I also discussed a similar problem to this with him and a professional framebuilder who is also a friend ( we were discussing a problem with a fillet brazed Higgins Trike Frame which had been run with the head assembly loose which had split the head tube) If you braze or weld tubing you get something called a 'heat affected area' . Like heating to harden or soften steel. My understanding is every time you heat it you edge the process along. ( We put a half lug over the tube to !correct' it and silver soldered it rather than replace the head tube)
I know the framebuilder uses a device to re shape deformed tubes on rebuilds of classic frames ,perhaps your framebuilder has done the same (and if they had spotted it they would probably have put it right without notifying you ) . I would be inclined to leave the brazed joints well alone personally .

[Valbrona]

It is hard to imagime 853 deforming like that during the framebuilding process ... the HT wasn't 853 in the first place? Framebuilders dunna like heat treated head tubes because of the difficulty to face/ream such tubes.

[sussex cyclist]

I assume the HT is 853 like the rest of the front triangle.

Here's a pic they sent me of the repaired tube:



The issue was on the lower left, where the wall of the tube appears to be thinner.

[slowster]

I presume that the head tube has now been reamed (re-reamed?) to ensure that the headset cups will be aligned, but because of the distortion reaming has removed more metal from the head tube in one place.

I don't know what to suggest. This is yet another occasion when Brucey's knowledge and advice is so sorely missed. Hopefully other posters with more knowledge will be able to advise you.

[rareposter]

I had an 853 tube cut out of a frame and replaced when it got dented; the repair and respray was so good it looked like a brand new frame. Rode it for another few years with no issues at all before selling the bike on.

You don't seem to have much luck with frames do you?!

That head tube looks perilously thin to me although I assume the frame builders are happy with it and know what they're doing...

Look at it this way though - if that was a mass production bike, you'd simply be given a new frame...

[531colin]

This is a bit of a tale of woe, isn't it?
I don't imagine an individually- built 853 frame is cheap.
The builders have sent it out ** wrong. ** (well, I don't think its right, and it can't be both right and wrong.)
When you have pointed out the fault, they have "repaired" it, but also offered you a more extensive "repair".
I'm guessing that they discussed the first repair with you? I think that if you have "accepted" a repair, you can't then return the item for a refund or complete replacement, which I think would have been my preferred option. (sale of goods act?)

Do you now have to accept a repair?
Is the headset a traditional headset with externally- visible cups, or is it an integrated thing where the bearing just drops into the end of the head tube?
If the bearing just drops into the end of that tube, that looks like a problem to me........the hole doesn't look round, and its very thin in one area.

What is the frame warranty with the existing "quick and dirty" repair, and what would the warranty be if they replaced the head tube?

As somebody already said, if it was a mass-produced frame you would simply have got a new one.

[pwa]

I would ask for a new frame, done right. Would you have paid what you did if you had known this is what you were going to get?

[slowster]

Tony Oliver commented on this subject in his book 'Touring Bikes', published in 1990. His preference with lugless frames was to use an oversized head tube with thicker walls, especially for tandem head tubes which he states are 'where most of the problems occur'. He was using a (probably long ago discontinued) Vitus 33mm tube at that time which was 1.5mm thick, unlike a 31.75mm diameter tube with 0.9mm walls. The 33mm tube was 'of sufficient thickness not to go oval when lugless brazed'. For lugless seat tubes (the other potential problem tube because it too requires reaming) he used a modified lug to sleeve the tube in otder to provide reinforcement.

Tony Oliver also mentioned old vintage Higgins Ultralight trikes, which were typically lugless, exhibiting bulging of the head tube around the area the headset was fitted, because after many years vibration and riding stresses would cause the thin, non-reinforced head tube metal to creep. I suspect that even if your frame is fine for many years, the head tube will similarly start to deform eventually.

In view of the above, if it were me I would opt to have the head tube replaced.

[mig]

one of the reasons i bought a few hand built frames back in the day was to avoid this very sort of thing. ie valuing the attention to detail that the maker should apply to the frame.

i'd ask myself one thing - would that thin bit be on my mind as i rode the bike? every time i launched downhill? every time i honked uphill? every time i had to yank the front brake as another car emerges from a side street.

it would me!

[peetee]

one of the reasons i bought a few hand built frames back in the day was to avoid this very sort of thing. ie valuing the attention to detail that the maker should apply to the frame.

i'd ask myself one thing - would that thin bit be on my mind as i rode the bike? every time i launched downhill? every time i honked uphill? every time i had to yank the front brake as another car emerges from a side street.

it would me!

Me too. I really don’t like the look of that reamed tube and can’t see it surviving the insertion of a headset cup.