alvinator

I want to put an Albatross bar on a Schwinn Letour Luxe that I just acquired but I need a long stem in 21.15 diameter. I was planning to have a Nitto forged stem machined from 22.2mm to 21.15mm; would that be ok to do?

well biked

I think it would probably be okay, but how would you do it? If you're thinking of a lathe, I don't think the shape of a quill stem is very conducive to that. I've heard of folks sanding them by hand, but 1.05 mm is quite a lot to sand, and they usually end with something like, "man, I'll NEVER do that again!"

I've got a tall 21.15 stem on my le tour luxe, I just watched ebay and nabbed it when it came up, it was about $6. Not as tall as a Nitto Technomic of course, but still a very tall stem. They're out there if you're patient-

kendall

can easily be done on a lathe, will take a bit of creativity to do, but anyone that's used a lathe for any time should be able to mount it.
Make sure that whoever does it leaves a fillet at the end of the cut to eliminate stress risers.

Ken.

cascade168

Sheldon Brown describes exactly how to do this on his French bikes pages. His low tech approach is to use emery paper and do it by hand!

Go to this page:

https://www.sheldonbrown.com/velos.html

and see the "Handlebars/stems" section for more.

well biked

To each their own. I still say with a little patience, a nice, tall 21.15mm SR stem (usually marked .833" on the stem) with a 25.4mm clamp diameter can be found on ebay. I know I found one.

well biked

Also notice the French stems are 22.0 mm, compared to the 21.15mm on old Schwinns. So you're only removing .2mm to make a 22.2mm stem fit a 22.0mm French fork, but you're removing 1.05mm to make a 22.2mm stem fit a 21.15mm Schwinn fork. Even then, it can be done I'm sure. But that's a lot of material to sand off by hand.

Of course, the poster above says it can done on a lathe. I'll take his word for it, but I don't think I could do it.

cascade168

Yup, you're right. I was thinking it was 0.1mm he needed to remove. I've done it a couple of times and it's not as easy as you might think. 1mm would take forever by hand. My bad (math).

Marlin

I tried sanding down a 22.2 mm stem to 21.5, but it would have taken a long time. I finally resorted to a grinder, not grinding above the point I wanted to insert it to. This stem was pretty thick, so I wasn't concerned with making it too weak. The result was not pretty, but the ground down area is hidden. I only did this to get a trial fit, not something that I will use permanently.

poopncow

re: Lathe, a 4 jaw chuck allows you to grab non-round objects. each jaw moves independantly of the others. set up, accuracy and machine time will depend on the skill of the operator.

I wouldn't bother unless I really really really want to & still have access to a shop

kendall

Myself I'd turn plugs for the bolt hole and inserted end, then center drill them and turn it between centers, maybe 20 minutes time. But I have lathes and mills here at home.

ken.

poopncow

can I barrow time on your machines ?

poopncow

Come to think of it, with the 4 jaw chuck, you'll still be best (need) to add a plug so that the end can be supported by the tailstock. Thanks for the idea Ken!

P

well biked

Something I've wondered about, what do you machine shop guys think about this: instead of altering the stem, what about reaming or boring the steerer tube? Schwinn wanted a thicker walled steerer, so the only thing that's different about the fork is the wall thickness of the steerer. Outside diameter of the steerer is the same as a standard fork, threading is the same, etc. Apparently they just used thicker material to make the tube. I've examined very closely Tange forks from old Schwinns, and compared them to a standard 1" Tange fork, and there appears to be no difference at all except for the wall thickness of the steerer tube. Is there a practical way to increase the inside diameter of the steerer tube by about 1mm?

nerobro

any machine shop can do it. most likely they'd use a boring bar.

rhenning

Of course you would pay $50 and up to have a machine shop do it when if you look a bit you can find one for maybe $10. Roger

kendall

rhenning has a point there, for a lot of things it's cheaper to find a ready made part that works as you want, in many cases it's easier to have it done at a machine shop. For -most- bicycle related items it's not cost effective to have a shop do the work.

It's only cost effective if you have access to the tools to do it, a lot of the things I make are only inexspensive because I have the tools, if I had to pay to have them done, or even 'rented' tool time, the cost would be far too much.

I originally got my tools because I did a lot of custom bike and car work, and the machine work was exspensive, so I spent $3k on lathe and mill, and saved over twice that the first year I had them on machine work, but I was sending work out three to four times a month

If you have the machines, know someone who has them, or can use them at a school/trade center, it's worth it, otherwise it's not, UNLESS you just have to use a certain stem or something that fits the look/style you want and isn't available in the size you need.

Ken.

Halthane

If you have access to a lathe with a four jaw chuck it'd be really easy to do actually. Mount the end to be turned into a drill chuck on the talistock to get it centered in the chuck. Chuck solidly, break out the chamfering cutter and go to town.

jsavage451

honestly a bit late on this topic but this thread helped me so i figured i would share what i found. I used a 21.15 stem riser as a makeshift threadless adapter. Sunlite makes it and i think you can find a few others too. then i cut it down as you would any new threadless steerer tube. make sure not to place a star bolt, it'll block the stem bolt. I did, however, take a trash star bolt and placed it inside a wine cork in order to fasten a top cap, otherwise you have a open hole at the top of the stem. other than that your best bet is boring out the inside of the steerer tube. i know 7/8th drill bits = 22.2mm so if you have a metal bore at 7/8th i think you could put it off that way, skipping the lathe. havent tried it yet though so dont take my word for it. hope this helps anyone else stumbling across this thread.

fietsbob

+1 another approach .833 tube type stem raiser ,
then a threadless type stem clamped around the stem raiser tube...
star nut is totally un needed ... it's a threaded headset..
just plug the top so It won't fill with rainwater.