Originally Posted by
macstuff
Thats ridiculous, you don't have to be a frame builder.
I have the deepest of mechanical experience a person can have, and what you are talking about doing is fundamentally wrong and dangerous. It has nothing to do with bikes and everything to do with a mild steel tubing, even ChroMo for that matter.
That doesn't mean don't do it, go ahead.... by all means, learn.
How does a stem attach?
One of the reasons that Schwinn went to 21mm stems was to bring the warrantee claims down. They were lifetime warrantee bikes.
When they did that, their "approved" suppliers had 21mm machinery to make stems for other companies. Cheaper so a few companies bought. Not many.
What was happening, and what will happen to yours, is a common occurrence. Tightening and loosening the stem again and again, or even a couple times too hard will push the wedge out and tear and bulge the steer tube. It may even be too thin to act as a footing for the swedge and push through the first time you tighten it down. The question isn't can you, it's should you.
As you mentioned somewhere up there, it must be hogged out to more than 22mm.... whatever to fit. there has to be wiggle room to insert the stem.
The steer tube becomes too thin. There are threads there on the outside not helping with this situation also. At that point it is a danger to ride.
I've pulled apart many old bikes with bulged steer tubes. It was a common occurrence in the "old days"
Best is to just buy another used fork for $30-50. We have a co-op salvage here where a proper 22mm i.d. fork for that would be $6
Im not dissin ya', you're just over thinking it as far as the steer tube is concerned.
Turning down, grinding down, honing down the stem is still just a hard answer to an easy question.
A cheap fork and you have a worldly choice of stems. Even a stoker adapter stem would be a good choice.
Just sayin'
i'm only going by what was
told me here at least once...THAT IT CAN BE DONE. and some of ya'll seem to think i'm dead set on doing it.
i'm not overthinking. if i don't fully understand something, i will ask questions until i do....unless i get frustrated and say eff it. but, given the contradictions between replies in this thread, isn't it easy to see where one might be inclined to continue questioning? for example, if the OD on a 21.1 and 22.2 steerer are the same, then milling the inside of the 21.1 would bring the wall thickness to the same as a 22.2 steerer, right? so, it would seem at least somewhat logical there's no problem given than millions of 22.2 steer tubes are out there UNDAMAGED. that being said, as it's been pointed out, there's risks. different types of steel. unknown factors. okay. i can accept that. i'd read elsewhere that one reason among others that schwinn used the 21.1 size was because they used a poorer quality steel and had to compensate somehow. and, eventually, they used better grades to where they then adopted 22.2. those bulged steerers i would imagine to be a symptom of that. plus, meat heads hammering down on the external hex head bolts that used to be used vs the allen heads. harder to torque those down as much....though, i'm sure it's been done
ps. of course you don't have to be a frame builder. that question was more about what are your qualifications? you gotta admit, there's a lot data that gets thrown around without experience to back it up. at least you didn't get ballistic like that one guy did...geez. iow's, thanks
