is a 2mm steel steerer tube thick enough to thread?
03-12-06, 07:28 PM
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Not something that I'd try.
What are you planning to cut the threads with? I own a set of taps for threaded forks, but I wouldn't bet on my ability to get the threads started squarely. This sounds to me like one of those jobs where the confidence level of the mechanic is inversely porportional to the likelihood that he's ever done it before.
What are you planning to cut the threads with? I own a set of taps for threaded forks, but I wouldn't bet on my ability to get the threads started squarely. This sounds to me like one of those jobs where the confidence level of the mechanic is inversely porportional to the likelihood that he's ever done it before.
03-12-06, 09:42 PM
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The wall thickness is likely thick enough, but it's not a good idea.
Reason 1 - As mentioned, getting the die started squarely would be difficult.
Reason 2 - The threads on production steerers are rolled instead of cut. Rolling actually deforms the metal surface and results in a stronger, more durable thread. Cutting leaves a jagged "V" shape at the valley in between each thread that can lead to a stress crack. The valley of a rolled thread looks more like a "U".
Reason 1 - As mentioned, getting the die started squarely would be difficult.
Reason 2 - The threads on production steerers are rolled instead of cut. Rolling actually deforms the metal surface and results in a stronger, more durable thread. Cutting leaves a jagged "V" shape at the valley in between each thread that can lead to a stress crack. The valley of a rolled thread looks more like a "U".
03-12-06, 10:06 PM
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Originally Posted by eddiebrannan
any help appreciated
However, you won't be able to fit a standard stem into it. I got bit by this once on a Gunnar. Had to take the fork to a machine shop to get reamed out to the standard 7/8" inside diameter.
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03-14-06, 10:02 PM
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Sheldon, have you ever noticed that once you enter a thread ...... it stops. Oh wise one!
03-15-06, 08:41 AM
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Originally Posted by toolboy
Sheldon, have you ever noticed that once you enter a thread ...... it stops. Oh wise one!
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03-15-06, 09:23 AM
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Originally Posted by Sheldon Brown
That's plenty thick enough, standard steel steerers are 1/16" (1.6 mm) thick.
However, you won't be able to fit a standard stem into it. I got bit by this once on a Gunnar. Had to take the fork to a machine shop to get reamed out to the standard 7/8" inside diameter.
Sheldon "Probably Better To Stick With Threadless. It's A Better System Anyway" Brown
However, you won't be able to fit a standard stem into it. I got bit by this once on a Gunnar. Had to take the fork to a machine shop to get reamed out to the standard 7/8" inside diameter.
Sheldon "Probably Better To Stick With Threadless. It's A Better System Anyway" Brown
Code:
+-------------------------------------------------+ | To stay young requires unceasing cultivation | | of the ability to unlearn old falsehoods. | | --Robert A. Heinlein | +-------------------------------------------------+
yeah i checked the fork and a standard stem fits in it, therefore it CANNOT be 2mm thick, despite the guy selling it to me saying "i don't know where you get those calculations from" like i'm making up the number of millimeters in a goddamn inch.
1.6 x 2 = 3.2 + 22.2 = 25.4mm = 1 inch, so yes, 1.6mm makes sense. thank you.
eddie "i don't care if it's a better system, there'll be no threadless doodads on my bike" brannan
03-16-06, 08:33 AM
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Originally Posted by eddiebrannan
yeah i checked the fork and a standard stem fits in it, therefore it CANNOT be 2mm thick, despite the guy selling it to me saying "i don't know where you get those calculations from" like i'm making up the number of millimeters in a goddamn inch.
1.6 x 2 = 3.2 + 22.2 = 25.4mm = 1 inch, so yes, 1.6mm makes sense. thank you.
eddie "i don't care if it's a better system, there'll be no threadless doodads on my bike" brannan
1.6 x 2 = 3.2 + 22.2 = 25.4mm = 1 inch, so yes, 1.6mm makes sense. thank you.
eddie "i don't care if it's a better system, there'll be no threadless doodads on my bike" brannan
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03-16-06, 03:57 PM
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i just measured another fork and discovered that while measuring w/ caliper that i was using the flat edge, so it gave me 2mm, but your correct it is 1.6mm, my bad! 
Last edited by na975; 03-16-06 at 04:56 PM. Reason: info
03-17-06, 11:53 AM
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no sweat na975, if you'd been right the fork wouldn't have fitted on my bike, so i'm glad you measured it wrong.
anyway, fork was cut and threaded with no problems whatsoever. as discussed we cut it a couple inches too long, threaded from there and then cut again to length. straightforward, albeit a good workout for the arms! certainly nothing to be wary of in the future.
anyway, fork was cut and threaded with no problems whatsoever. as discussed we cut it a couple inches too long, threaded from there and then cut again to length. straightforward, albeit a good workout for the arms! certainly nothing to be wary of in the future.
03-17-06, 01:18 PM
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yeah the clearance with the downtube isn't quite that tight. about half an inch at the closest point
