Is there a tried-and-true way to unstick the handlebar clamp on a Cinelli 1R stem?


Pic from velobase:



https://www.velobase.com/ViewComponen...=102&AbsPos=50

The 1R had an internal wedge built inside it if I'm not mistaken. PB Blaster and some time, maybe a bit-O-heat.

Yes, it's the wedge. I'm thinking that if I put a tool in there, I can push it backwards.

Loosen the bolt and tap up on it.

Wedge possibly cracked (and toast) and that's jamming things? Here's a couple photos of the parts: in the first, Stem, with screw and steel wedge installed and also lying on the side, and the "white metal" wedge/clamp that fits against the bar. That one's cracked.



In the second, three bar wedges, two of them cracked -- shows that they don't always fail in the same place.

Lube and tap. Do not put heat on it, that's way off base.

This happens a lot. A dead blow hammer at the faceplate usually works, easy does it.

Because the 1R is a poorly designed stem.

I think it's more the materials available at the time.

and the XA.....

I wonder if they tried making the 1R's white metal wedge out of steel.

Sooner or later I'm gonna make some billet 7075 1R wedges...sooner or later.

BTW...What's wrong with XAs???...I have those on a bunch of bikes, 26.4 and 26.0...zero issues.

They crack across the front...

Most likely a small sample from people over tightening 26.0 bars in 26.4 stems, if I had to venture a guess.

I'll take a couple of those 7075 wedges...sooner than later. I've busted a couple!

Guilty...& right in front as mentioned. On a pantographed Merckx XA stem too.
All the other XA's I have (4) are OK. One w/ a shim to hold ITM bars from slipping....

Thanks for the responses.

Charles, that photo break down was super, super useful.

I unscrewed the bolt, gave it a light tap, and the bar was free.

I now have a pair of 64-40 Cinelli's in 26.4 for trade for a pair of 44's

EDIT: And it took me longer to write this post than to free the bars.