motobeprof

I'm having trouble removing an old (1970's) TTT Record stem from the TTT drop bars. I want to mount another bar. I've loosened the clamp bolt and pried the clamp open slightly, but the bar won't come out. There is clearance between the two such that it should slide right out, but no such luck. When I turn the stem, its gouging the bar. What's happening here?

bikeman715

there maybe a burr on the bar than need to be file down before they will come out.at one point in the life of your bike someone may have tighten the clamp to tighten and cost the burr.

MichaelW

You need to rotate the bar within the open stem clamp to avoid gouging. I think the bottom of the clamp is narrower than the top to any curve in the bar has to fit around this shape.

FBinNY 

+1 Brute force won't work here, it calls for finesse.

The stem is cut narrower at the bottom precisely enough to clear the curves, so you need to rotate the bar at each bend to line up the narrow section of the stem with the inside of the curve at that point.

If the stem doesn't have ttt's self wedging system to keep it open, Try this trick to keep it open: remove the pinch bolt, and thread it in from the wrong side, put a penny into the slot, and tighten the bolt to jack the stem open about 1mm while you work the puzzle. Do not ever-expand the openning to try to clear the bar, it'll weaken or crack the stem.

motobeprof

The top and bottom of the stem clamp are symmetric and the bolt hole has no threads, just a through hole. I cannot even get the stem moved more than a half inch from its centered position on the bar. It's as if there is some sort of pin inside the stem clamp that is intended to keep the bar from rotating. Prying the clamp open is very tricky... I don't know how I'll ever get the stem mounted on the new bar!!!

FBinNY 

Unless someone did something weird (which should never be discounted), there's no mechanical connection between the bar and stem. Odds are there's some bit of corroded metal that transfered between the two parts over the years. Working it back and forth dry will only make things worse.

Improvise a reliable wedge, like a piece of wood you can tap into the slot to keep things open while you work, (I use pennies, one of which is filed into a wedge) then use an anti-galling oil such as "Kroil" (available in hardware or automotive stores), or other oil thinned slightly so it wicks in nicely, to keep the parts free as you try to work the bar out. Try to rotate less and push horizontally more during the process. If it still feels pinned, pass a length of dental floss into the slot and try to work it all the way around to locate the specific source of the binding.

As you work it out, keep it well lubed, and once beyond the ferrule or bulge use finesse to navigate the turns.

Worst case scenario, if you want to save the bar and are willing to sacrifice the stem, saw a deep slot across the top, the spread it open until it cracks, but let's hope it never gets to that.

motobeprof

Ok, I got the bar off the stem. Had to destroy the bar, but the stem is what I really wanted. It looks like my mistake was to try to twist the bar off before adequately prying the stem open (as noted in the forum comments). This caused severe galling, as seen in the photos. I polished this out with some emery cloth wrapped around one end of the old handle bar. This worked out fine and I'll be able to use the stem to mount the new bar on my new (old) fixie. Thanks for your help!

FBinNY 

I'm glad it worked out, and that the galling wasn't severe enough to destroy the stem. Two suggestions for the future.

1- never try work two tight pieces of metal apart without introducing oil as an anti-galling agent.

2- look again at the stem, as we said earlier, it definitely is cutaway slightly at the bottom. It'll be important to keep this area at the center of the turns when threading the new bar.

DannoXYZ 

It appears from the photos (4th) that the narrowest part of the stem is right under the clamp bolt. Just rotate the stem so that this part is on the inside (tightest) curve part of the bars and it'll slide off easily.

It appears that this stem was forced apart to fit a larger bar than the stem was designed for. In which case, it most likely cut some gouges into the bar at the edges of the clamp which prevented it from sliding out easily. The forced-apart clamp also means it won't be as easily spread apart even more to release the bar. The clamp should have its mating faces at the clamp parallel, not angled outwards like in the last photo.

Also would be a good idea to polish the inside of the clamp down to a 400 AR finish. The ragged rough surface you have now is ripe for introducing cracks. Also deburr the edge of the clamp so you don't introduce stress-riser scratches into your new bar. TTT stems are typically 26.0 or 26.2mm, make sure your new bar is the correct size.