Bicycle Mechanics - threaded steer tube replacement on vintage bianchi

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stormywaters
01-29-06, 12:14 PM
well, something terrible happened.

my new (to me) 1983 Bianchi Super Leggera Specialissima was assaulted.

i was at the local bike shop, getting the headsets switched out on my new and old Bianchis, when the person working on my bike made a grievous error. Said person was not being careful with a certain tool, and preceeded to cave in the top of my steer tube. After much panic, the lead mechanic cut the top of the steer tube and was able to get the top of the headset thread on what was left of the steer tube.

After everything was said and done, there was probably 3mm cut off of the top. Since there was so little material available to cut in order to get the headset to thread back on, they couldn't remove the entire caved in portion. That being said, the threads at the top of the tube are flared out and up, and the once clean and factory perfect fork is now hacked. Yes, the headset tightened back up, but I don't know how confident I am in this "repair".

am I over reacting? is there nothing wrong here? the bike is full columbus tubing, and that raises the question: if I decide to have the steer tube replaced ($125 at Joe Bell and Cyclart here in town), is the steer tube made out of columbus SL tubing or just the fork blades?

little help?


Sheldon Brown
01-29-06, 12:25 PM
i was at the local bike shop, getting the headsets switched out on my new and old Bianchis, when the person working on my bike made a grievous error. Said person was not being careful with a certain tool, and preceeded to cave in the top of my steer tube. After much panic, the lead mechanic cut the top of the steer tube and was able to get the top of the headset thread on what was left of the steer tube.

After everything was said and done, there was probably 3mm cut off of the top. Since there was so little material available to cut in order to get the headset to thread back on, they couldn't remove the entire caved in portion. That being said, the threads at the top of the tube are flared out and up, and the once clean and factory perfect fork is now hacked. Yes, the headset tightened back up, but I don't know how confident I am in this "repair".

am I over reacting? is there nothing wrong here? the bike is full columbus tubing, and that raises the question: if I decide to have the steer tube replaced ($125 at Joe Bell and Cyclart here in town), is the steer tube made out of columbus SL tubing or just the fork blades?

My advice is to ride it. If it turns out to be a problem in practice, the problem will be a tendency of the headset to loosen up, not earthshaking nor life threatening. Only consider having more work done on this if the problem actually occurs.

I don't believe there's anything particularly "SL" about the steerer. That $125 price sounds very low to me, must not include paint...

Sheldon "CyclArt Paint Isn't Cheap, But It's The Best" Brown

+-----------------------------+
| Razors pain you; |
| Rivers are damp; |
| Acids stain you; |
| And drugs cause cramp; |
| Guns aren't lawful; |
| Nooses give; |
| Gas smells awful; |
| You might as well live. |
| --Dorothy Parker |
+-----------------------------+

shiftinjon
01-29-06, 12:42 PM
There is a standard here that must be met in order for you to even consider this to be safe to ride. The headset locknut must thread on a minimum of three full turns/threads to be considered fully engaged.

IMHO you have every right to expect them to restore this to the condition it was before their negligence. A partially caved in steerer would not be acceptable to me. And any quality butted cromo steerer should be fine as a replacement.


shiftinjon
01-29-06, 01:01 PM
My advice is to ride it. If it turns out to be a problem in practice, the problem will be a tendency of the headset to loosen up, not earthshaking nor life threatening. Only consider having more work done on this if the problem actually occurs.My experience is that a loose headset can cause a front end shimmy which can lead to an accident. A loose headset will also lead to premature wear on the headset. I would recommend that if you do decide to ride it as it is, you should be very cautious.