stem question
 

I'm no mechanic, so maybe my question is quite simply answered at the beginning of next week when the bike shop opens. Here's my issue:

When I was getting bikes ready for the nice weather we're having, I noticed that my more comfortable bike, a Motobecane Jubile Sport, has the handlebar stem extended twice as far as my Schwinn Traveler, another bike of otherwise the same geometry. Naturally, I decided to raise the handlebars on the Traveler. I unscrewed the long bolt and tried to pull the stem. It wouldn't budge. I read somewhere that to allow the stem to come loose sometimes a gentle tap does the trick. So, that's what I did, and I was able to work the stem up to match the height of the Moto's.

I noticed a line with an arrow drawn to it on the stem. I'm pretty sure that line shows maximum height the stem can be extended. I lowered the stem to that line, and tried to tighten the bolt. I wouldn't tighten. I took off the front wheel and looked up the headset from the bottom. I see now that I can barely make the stem go up without disallowing the bolt from connecting with the nut inside the headset.

Is it fair to say, given these observations, that I'll need a longer stem and bolt from the bike shop? The stem is only about four inches long.

I think what happened is that you only dislodged/removed half the (quill) stem. The half still inside the tube is the "wedge" part, which when pulled toward the top part by the bolt, slides sideways to secure the whole stem in the tube by friction.

You need to push the stem in, thread the bolt back into the wedge part (not tight), then gently tap the bolt to dislodge that bottom wedge. That wedge can get stuck in there pretty tight, especially if too little grease was applied to it originally, so I'd suggest spraying some penetrating oil inside the tube all around the perimeter of that wedge. Use PB Blaster or Kroil if possible, but at least something like Liquid Wrench. Let it sit awhile, tap/bang again, and repeat (perhaps letting it sit O/N).

You were right about the maximum safe height line -- there's a similar line on seatposts.

Thanks. That makes perfect sense. My review of online instructions only revealed drawings. Sometimes, drawings can be misunderstood by those, like me, who haven't actually seen the parts disassembled. Fixing the problem right now.

Note the important part about screwing in the bolt to the expander wedge that's stuck in the steerer-tube. This prevents damaging the threads when you tap/bang on the bolt (not the stem).

Typically I'll unscrew the bolt about 3-4 turns, then tap the back of the allen-key with a hammer to dislodge the expander. The stem is then released and you and move it up or down to adjust. Then tighten the bolt.

On really stuck expanders, I use a socketed allen-key to give a flat surface to whack with a rubber mallet. Or lay a piece of wood on top of the allen-socket and smack with 10-lb dead-weight mallet.

I'll be sure to screw the bolt into the expander wedge first a little before tapping. Thanks.

Update: The danged expander is still stuck. I used penetrating oil, tapped. Then I waited all day, reapplied penetrating oil, tapped. Nothing. Won't budge.

Wondering if I'm just not tapping hard enough. I'll try again tomorrow. Hate to have to take it into the shop for something that seems like a normal fella oughta be able to do.

I believe many forks have thicker tube walls down close to the crown - possibly the wedge is lodged down in the reduced diamter.

Try taking off everything that is blocking access to the bottom of the fork (brake, fernders, etc.), then thread the bolt in from the bottom and tap with a hammer to dislodge the wedge. Try to be gentle and do not bend the bolt.

Yeah, how far down the steerer is the expander? Use PB-Blaster, much, much better than Liquid Wrench or WD40. I've had stuff stuck so hard I couldn't free it, even with Liquid Wrench followed by pounding with a 10-lb hammer (mushroomed and destroyed the allen-key socket). Then I sprayed PB-blaster and set it aside. A couple hours later, I heard the plink of the expander falling down inside the fork on its own...

[QUOTE=keiththesnake;8535061]Wondering if I'm just not tapping hard enough.QUOTE]

Correct. "Tapping" isn't what you should do. As already recommended, use PB Blaster, and if it's still stuck, hit that sucker HARD, and repeatedly if necessary, using a hammer. You're not going to hurt anything on that old Traveler.

And consider yourself lucky:), because all you're dealing with is rust between the wedge and the steerer tube. What's really bad is when galvanic corrosion sets in between the aluminum stem and the steel steerer tube. The two parts might as well be welded together in some cases, and it's a royal PITA to free them-

Umm, most likely do not have n adjustable stem or head on the bike.

It's been suggested that I most likely don't have an adjustable stem or head on the bike. How can that be? I mean, the stem's got a maximum safe height line on it, so isn't it fair to assume that the stem's adjustable? I've never read about a Schwinn from the 80's that you couldn't adjust the stem height -- not that I'm claiming to know more than anyone, that's why I'm here asking.

I think my next move will be to remove the tire and brake assembly, spray some more PB in there, thread the bolt in from the bottom, and give it a good whack or two from the other end. That makes sense. It makes sense especially if the inner diameter of the head tube is really more narrow at the bottom than at the top.

So, as you can probably guess, I'm still in the same boat with the stuck wedge.

Don't worry, you've got a quill-stem that goes inside the fork's steerer tube. Just soak the stuck wedge with some PB-blaster, re-install the bolt. Install a socket and WHACK it with a hammer. :)

Going from the bottom is a good idea, but most of the time, you want to WHACK in the opposite direction as the original pull. Sometimes they actually bite into the metal of the steerer tube and you want to move it out in the opposite way it dug in.

If it's that stuck, I might suggest leaving it there. You mentioned you had two bikes with the more comfortable one with a higher stem. I say keep the one with the frozen stem in that position for when you've got stronger legs and can sustain a lower bar position.

Victory today. Took the rubber mallet to it with the bolt backed off the wedge a few turns. The penetrating oil did the trick, I guess, because there wasn't much weight to the mallet. Shows a little rust, so I'm going to clean it up and apply some white grease before assembly.

Now, I'm going to see if the longer stem from an old Azuki that I have laying around will fit. If it's a hair too big a diameter, I can handle that. Too small, and I'll have to look elsewhere for the fix.

Ignore that comment. You have an adjustable stem. I don't think I've ever seen a non-adjustable stem. I've seen fork/stem combos that had no room for adjustment, but they are still adjustable.

If you could get in there with some sandpaper or a really stiff bottle brush and smooth out the surface, then grease up all the entire interior wall surface, it would tend to stabilize that inner surface and ease future adjustments.

If your Traveler is 1984 or earlier, it will need a 21.15mm (.833") diameter quill stem. The much more common size is 22.2mm. It's enough of a difference that it's generally impractical to try and use a 22.2mm stem in a 21.15mm steerer tube unless you're good with a lathe and have access to one. Maybe the Azuki uses a 21.15mm stem as well, or maybe your Traveler is later than 1984, anything's possible. Some old Nishiki's used that size as well as decades of Schwinns-

I'm proud to announce that the longer stem off of the Azuki fits perfectly in the Traveler headset. I'm cleaning out the headset tomorrow and adding white lithium grease before assembly. I'll have the job done tomorrow.

The whole time actually spent on the project was about 15 minutes, even though I spread it out over a number of days. Once the stem and handlebars are installed, I'm going to apply white hockey tape with stained shellack to match the Brooks saddle I bought used last season. If I'm too cheap to buy a new stem, I'm too cheap to buy Brooks bar tape.

Project is complete. Thanks for the good advice.

How about posting some pictures? I mean - it's a delusion you're suffering from unless we can see some pictures!

Traveler Headset stem size
 

So how do I tell the stem size?

Dude, lower that stem!

It's a good two inches above its minimum insertion mark. Carnage in 3... 2...

Kimmo,

I understand your point. I think (hope) she's rusted on by now. I've been riding with it "barely in" for half a year. Ride about 11 kilometers each way to work into the city. I have found replacement stems, just trying to fitgure out what is this stem size so I CAN replace it with something that fits. Hurts my back to put stem back down. I don't know if I could "cheat" and bring the handlebars up (kind of upside down). As soon as I get a higher replacement stem, I WILL put something in much safer. Kimmo, appreciate the response regardless. Hopefully the carnage you speak of is, will not happen.......

No seriously lower the stem. Whatever discomfort you feel now will seem like nothing once you end up with a broken collar bone from the ensuing crash.

So stem should be lowered. I know, I know.

To replace the stem, I see on pictures that have been sent suggest the bike is a 86 or 89 frame and the stem is a SR Custom Alloy 100 mm. So I can go online and order a 130 mm 22.4 mm or 25.4 mm (opening?) quill, threaded stem? Does that fit this, does anyone think might be correct? I still do not understand how to determine the opening, is it 1" or 1 1/8"?