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Old 07-31-10, 09:32 PM   #1
tmh657
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Ebay frame purchase has head tube roundness issue. Repairable?

Bought a frame on ebay and it arrived in the cosmetic condition as described and pictured n the auction. It's from 1999 and Reynolds 853 tubing.
Came without fork or anything else. Bought new headset at LBS and had them install it. Put new carbon fork in and it did not turn smoothly. Put in another new headset, same issue.

Inspect headset cups and they have a definite flat spot on one side. It's like the head tube is not perfectly round on the inside. Is this something that can be repaired ?
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Old 07-31-10, 10:21 PM   #2
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Have your LBS see if the head tube can be reamed.
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Old 07-31-10, 11:03 PM   #3
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sometimes a crushed headtube has to be bent back round. If you ream them when they are too d-shaped it can result in too thin of a wall and result in eventual failure.
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Old 08-01-10, 05:41 AM   #4
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The shop that installed the head set said the frame is damaged, period... no mention of trying to ream it so I am thinking I will go to a different bike shop and get input from another mechanic or look for a frame specialist. I don't want to drop a bunch of money on a $150 frame.

I suppose I could contact the ebay seller and just ask him to take it back but I have been looking for a nice steel frame in my size for awhile.
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Old 08-01-10, 09:24 AM   #5
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The headtube needs to be worked to as close as possible to the original round shape. If it was already reamed to size, reaming anew will remove more metal resulting in an oversize hole. It need not be absolutely perfect, since there's some spring to the metal, and will conform (within bounds) to the flange of the headset cup when it's pressed in.

If possible, reface the headtube to bring it to perfectly square, with out reaming (some ream/face tools make this possible using a non-cutting guide, others don't). That will ensure proper seating of the cups.

There's also another possible issue. It's possible that the same forces that flattened the tube, might have introduced some flex over it's length. If that's the case, the two pressed in cups will not share a common axis, which is critical to good headset function.

I suggest you consult another shop, but be very clear that you do not want them to ream the tube, because that will cause issues that will be difficult to resolve later.
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Old 08-01-10, 09:38 AM   #6
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Might be able to put a steel headset in there and force itself in and roundif its not too ovaled you might try a cheap steel one and press it in,
then try the light alloy one you would likely prefer.

a good machinist could make a tool to expand the inside of the tube,
I expect My father could , but at 80, he passed on 9 years ago.

Or, A tapered piece of steel, perhaps, to bang onto could round out at least the outside edge, and that may get it closer so the headset reamer would not take out too much head tube wall thickness..

Heat will pull the tube out of round while being brazed , I have my DIY lugged frame from 25 years ago
I'm still using it occasionally. it ovaled out a bit the ream did thin part
of the tube more than the other and it's still serviceable .
[I'm using a steel Ofmega/ 'Avocet' headset]

I believe it could have been lessened if I used a longer tube for the headtube and cut it after the braze cooled.

Buying a frame jig which fills the tube with a plug to hold it round while hot, will of course help.

Last edited by fietsbob; 08-01-10 at 09:45 AM.
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Old 08-01-10, 10:22 AM   #7
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Quote:
Originally Posted by fietsbob View Post
Might be able to put a steel headset in there and force itself in and round if its not too ovaled you might try a cheap steel one and press it in, ...
A older steel headset might solve the problem being sufficiently rigid to flex the tube to spec, but it won't solve anything and the tube will likely ovalize when it's removed.


Quote:
Originally Posted by fietsbob View Post
.....Heat will pull the tube out of round while being brazed , I have my DIY lugged frame from 25 years ago
I'm still using it occasionally. it ovaled out a bit the ream did thin part
of the tube more than the other ....
That's why raw tubing for headtubes comes with an undersized ID. It's designed to provide enough material to allow some distortion and for reaming to spec. after brazing. Once it's reamed, and ovalized again, removing more metal will result in a sloppy fit.

If you have decent hand skill you can probably correct it yourself with a piece of pipe and block of soft wood. Find the largest pipe which will fit into the headtube. If the flat area is small enough you might be able to flex it back simply by levering the pipe against a point 3-5" down in the tube. use judgment because you don't want to bulge out the area you're using as a fulcrum. For a more sever bend, shape a curved saddle into a block of wood to accept the tube & support it on some sort of an anvil, place the pipe over the damaged area as a mandrel and hammer back to shape. Check your work frequently to avoid going to far and flaring the end of the tube. Once you're close, the cup should be able to flex it as it enters.
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