Bicycle Mechanics - overtightened quill stem - steerer damage

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LP-NZ
08-26-07, 11:15 PM
I am usually pretty cautious about riding damaged parts for fear of catastrophic failures. However, I have recently purchased a used early 80's sarroni, and while giving it a bit of a pre-ride check over (after I had got it home) I realised that the previous owner had overtightened the stem (on a number of occasions by the looks of it), with the result being a number of concentric bulges in the steerer tube. Is this type of damage safe to ride on? Logically I doubt that this is likely to weeken the steerer that much, but it goes against the grain a bit to ride on a damaged fork. I guess I could always try and find a replacement, but part of the attraction of the frame was that it had the original fork.

Any advice would be gratefully recieved.


Handyman
08-27-07, 12:14 AM
I'm only a mechanic of the shadetree variety so I don't know the exact physical properties of your particular hardware. That said, I'm going to suppose your stem has parts similar to anything I've ever worked on - cups, cones and caged ball bearings. The cups are probably pressed into the headpiece tube and are the same, both top and bottom. Remove the cups, clean all the parts and apply fresh grease, install the top one on the bottom and the bottom one on top. As long as nothing is cracked or broken this method is usually adequate to get rid of the "choppy" feeling when steering.

skinny
08-27-07, 12:25 AM
I am usually pretty cautious about riding damaged parts for fear of catastrophic failures. However, I have recently purchased a used early 80's sarroni, and while giving it a bit of a pre-ride check over (after I had got it home) I realised that the previous owner had overtightened the stem (on a number of occasions by the looks of it), with the result being a number of concentric bulges in the steerer tube. Is this type of damage safe to ride on? Logically I doubt that this is likely to weeken the steerer that much, but it goes against the grain a bit to ride on a damaged fork. I guess I could always try and find a replacement, but part of the attraction of the frame was that it had the original fork.

Any advice would be gratefully recieved.You should keep your eye on it because the steerer could split, especially if the bulging is in the threaded area, causing the stem to come loose and then, well, you don't need me to describe the rest. Whether it is safe or not is entirely up to your judgement based on your observations. You may also find it difficult to remove the fork crown race if that is ever necesssary.

A new steerer can be brazed in by a frame builder, and the fork could be chromed, which would be period correct for this bike.


tellyho
08-27-07, 11:26 AM
Handyman, I think the OP's talking about the steerer and stem, not the headset.

I'd be wary of riding it, and would either get a new steerer or a new fork.

howsteepisit
08-29-07, 04:25 PM
If its a steel fork and steerer, no problem except getting the stem to tighten proerly. If you can find a position where the stem tightens properly you're golden, if not rplace the fork

roadfix
08-29-07, 04:34 PM
My steerer did split from overtightening. It split right at the notched cutout on the lower threaded portion. I knew something was not right as the stem kept turning out of alignment with the front wheel no matter how many times I re-aligned it. This happened with a Euro stem which uses a wedge different from the 45 degree angled wedge. I've never had this problem with stems using an angled wedge.