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Thread: 21.1 stem?

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    21.1 stem?

    I was given an older (1977?) Schwinn Super LeTour 12.2, It's a nice bike, but I'd like to raise handlebars to a get a more comfy riding position. Unfortunately, the stem isn't long enough. To compound the problem, this bike has a 21.1mm (.833") stem. Needless to say, there isn't a great selection of stems in this size. I searched for earlier threads about this situation, and none of them discussed reaming the inside of the steerer to accept a standard quill stem. Is this unsafe/too difficult/impractical/just plain dumb? Seems as reasonable as sanding down a standard quill to fit, except that once the steerer has been modified, it'll accept any standard road quill.

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    I wouldn't think reaming out the steerer tube is a very good option. I had the same problem on an old Nishiki I acquired. I started in grinding down a standard 1" stem and gave up when I realized how considerably much needed to be taken off. I eventually just picked up on ebay a nice older fork with a standard sized steerer tube. The replacement fork turned out to be a nicer one anyway and fit just fine inside the headtube.

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    Senior Member sydney's Avatar
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    Quote Originally Posted by dbg
    I wouldn't think reaming out the steerer tube is a very good option.
    Not an issue if it atually has more metal in it. A kubiki or some other POC I had certainly had a thicker steerer tube,that was threaded for standard 1".And that is typically the case. But, a proper used one could be cheaper.

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    Senior Member sydney's Avatar
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    Quote Originally Posted by drcrash
    I was given an older (1977?) Schwinn Super LeTour 12.2, It's a nice bike, but I'd like to raise handlebars to a get a more comfy riding position. Unfortunately, the stem isn't long enough. To compound the problem, this bike has a 21.1mm (.833") stem. Needless to say, there isn't a great selection of stems in this size. I searched for earlier threads about this situation, and none of them discussed reaming the inside of the steerer to accept a standard quill stem. Is this unsafe/too difficult/impractical/just plain dumb? Seems as reasonable as sanding down a standard quill to fit, except that once the steerer has been modified, it'll accept any standard road quill.
    Have you checked the inside diameter of the steerer tube. Sometimes it's ok,and it's just the lock nut on the HS that is smaller. If that's the case the HS can be opened up a bit or the locknut replaced.

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    Senior Member biker7's Avatar
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    as usual sydney/bore-troll doesn't know what he is talking about. What you need is a Nitto Technomic stem. Comes 22.2mm quill dia. and is very tall. They also come in many different reaches. You simply take a bit of sandpaper working to progressively finer grit media to bring the quill diameter down just a bit to fit into your SS steerer which has an I.D. of just under 22mm. Its a better alternative than honing the fork I.D. which some do. Go to Sheldon Brown's/Harris Cyclery's site and they talk about them. You can find them from time to time on e-bay as well. I have one on an early 70's Paramount and they are very nice.
    Here's one with 4 hours left:
    http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

    If you get one, be sure the stem clamp dia. matches your handlebar dia. Your super sport has a 1 inch bar...so if you purchase the 26.0mm stem, you will need the Nitto shim which they also sell.
    Enjoy that old SS.
    George

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    OK. But if it truely is a 21.1 bore steerer tube, the sandpaper route will require about 10 thousand sheets and some seriously dedicated elbow grease. 21.1 does exist out there. I have a Nishiki fork in front of me right now that is definitely 21.1. And the Schwinn Twinn tandem I recently restored also definitely has a 21.1 steerer tube. 1.1 MM doesn't seem like much until you try to remove it.


    "It's a small world, but I wouldn't want to paint it" -Steven Wright

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    Senior Member sydney's Avatar
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    Quote Originally Posted by dbg
    OK. But if it truely is a 21.1 bore steerer tube, the sandpaper route will require about 10 thousand sheets and some seriously dedicated elbow grease. 21.1 does exist out there. I have a Nishiki fork in front of me right now that is definitely 21.1. And the Schwinn Twinn tandem I recently restored also definitely has a 21.1 steerer tube. 1.1 MM doesn't seem like much until you try to remove it.


    "It's a small world, but I wouldn't want to paint it" -Steven Wright
    Correctomento. There really are 21.1 quills and steerers with an ID that require them. I's good to have actually seen some of this stuff.

  8. #8
    Senior Member biker7's Avatar
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    dbq,
    I didn't have any problems removing .040" but then I have done a lot of mechanical work and am pretty strong. Aluminum is very easy to take down. Good long quill stems like the Technomic are as rare as hen's teeth now. Perhaps you would like to direct the poster to a site that sells a stem as "long as the Technomic" that will fall into a Schwinn steerer and save him the handy work. I have several shorter stems that will fall in. In fact, here is a pic of the stem from my '77 Schwinn Le tour which is a close cousin of the poster's Super Sport.

    http://members.roadfly.com/georgemann/SchwinnStem.jpg

    George
    Last edited by biker7; 03-21-05 at 04:11 PM.

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    I felt like an idiot after an hour on a bench grinder trying to get a steel quill down to 21.1. I suspect aluminum would be easier. And hopefully it's not actually 21.1. Is the pictured stem unmodified, or was it ground down to fit?

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    Senior Member biker7's Avatar
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    that's an unmodified std. Le Tour alloy stem. A Technomic stem has a much longer quill and what the poster is looking for. Aluminum is much easier to machine than carbon steel. I put myself through engineering school working at a machine shop and so played around alot with machining different materials. I have access to a prototype shop at work which is great for government work :-) Taking an alloy stem down with a belt sander goes fast....the trick is keeping it concentric. First you bring it in to approximate size and then you finish polish it. Machines help a lot but you can do it by hand as well....a bit at a time.
    Cheers,
    George

  11. #11
    Senior Member sydney's Avatar
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    Quote Originally Posted by biker7
    Machines help a lot but you can do it by hand as well....a bit at a time.
    ....and more than 'a bit of sandpaper'.

  12. #12
    Senior Member jeremyb's Avatar
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    always could use something like this

    http://www.ebikestop.com/pyramid_qui..._dia-57657.php

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