MetalPedaler

Hey Guys!

I just bought a 97 Klein Quantum Race, and while assembling it, I noticed that there was no expander wedgie thingy on the end of the stem- it looked like this:


Well, I've never seen a quill stem without an expander, but i don't have experience with bikes- so I inserted the stem into the headset and tightened the bolt- and VIOLA[sic]- it threaded into something.

What am I missing [as in not understanding] here? Is the expander merely already down in the headset, and...no...wait- this stem isn't even shaped like the other quill stems I've seen before, on the bottom end- maybe this is some kind of different system? I don't know- edumacate me!

What do I have here? (If you could provide a diagram as to what's inside the headset, instead of the usual expander bolt, it'd be helpful)

Anyone?

FBinNY 

Either the wedge was already stuck in the fork, and you happened to pick it up with the bolt, or it's tucked inside the stem and you missed it.

It's easy enough to find out. Loosen the expander bolt until it rises about 5mm, and no more. Tap it down to free the wedge, and remove the stem, and the wedge will still be hanging on the bolt where it belongs.

MetalPedaler

Thanks. I was actually thinking of doing that- but just thought I'd check here first- figuring maybe this was some kind of different system that I had never seen before.....

dsbrantjr

It looks like you have the "cone" type of expander. See the leftmost photo in this reference: https://en.wikipedia.org/wiki/Stem_(...t)#Quill_stems It looks nearly identical to yours; the cone inside has its small end upwards toward the bolt. Like the wedge type, make sure that you grease the internal and external parts so that the stem does not seize into the steerer.

EDIT: Here's a picutre of the bolt and cone, to save you taking yours apart to see what's inside: https://www.ebay.com/itm/CINELLI-allo...p2047675.l2557

FBinNY 

I didn't mention this earlier, but I suspect you have a relatively short frame, and the stem was possibly inserted fairly far.

Fork steerer tubes are reinforced internally at the bottom 2 inches or so. Above that the ID tapers open until it's the standard 7/8" diameter. When totally unscrewed the wedge drops down and jams in this tapered transition zone, which is how you were able to pick it back up by pushing the stem down then tightening it.

If you do have a short frame as I describe make sure not to push the stem all the way down until it bottoms out. Keep it about 1/16" above that so you'll always be able to push the wedge clear when you want to remove it.

MetalPedaler

We think alike! I had just found a similar pic on Ebay, too, by searching for this stem. I KNEW it had to be something like that [or a wedge that stayed inside the headset]- It dawned on me after I went to bed, that there was no way it could be regular expander wedge, since the bolt does not extend down past the bottom of the stem.

Just out of curiosity: Would the other type of stem [with wedge expander] work in there, if I ever had to replace the stem?

Ah well, I have to take it apart anyway...to grease it. Thanks for the tip!

FBinNY, It's a 55cm frame- but these Kleins do have rather short head tubes- which might explain the fact that this headset has a big spacer.

-DGDescapeefromNY

dsbrantjr

Further to what FB states, when you install the stem be very careful NOT to bottom it out into the tapered section at the bottom of the steerer. If you expand it into the tapered section it can let loose without warning exactly at the wrong time. See this reference https://sheldonbrown.com/handsup.html#threaded and scroll down to the "Too Low, Danger!" section for an explanation and a diagram, which includes a cutaway diagram of your cone type stem. Handlebars coming loose is only funny in the cartoons.

dsbrantjr

Yes, the wedge type should work provided that it is the correct diameter and has enough steerer length to not bottom out.

MetalPedaler

Excellent! I had tried looking on Sheldon's site last night...but didn't find that!

[Wow- that diagram says it all- that was something I was never aware of! This is probably the single most important thing I have learned about bikes, in.....ever!]

MetalPedaler

Oh, and while I have youse guys: The nut on the very top of the headset- on top of the spacer- is there any special way I need to torque that or anything? it was loose when the bike arrived- but I don't really think it was necessary for the previous owner to have loosened it to remove the stem....