70slibrarymusic

Hello again! I've made a previous post mentioning this problem before but I feel like it got buried among the other questions. Wanted to get more opinions by posting it on its own with pictures.

So I've managed to take out the quill stem problem is the expander seems stuck on the bolt. I took out the little tiny screws holding the expander in place and managed to get both that and the bolt out. I'm not sure if I'm missing anything but this thing would not budge at all even after about a week of soaking with WD-40.

Was wondering now if I can just put the stem in without the little bolts holding the expander in place. Since the main stem bolt still turns, theoretically it can still wedge the expander up right? Would this be safe? Thoughts?

sovende

I don’t have any experience with the Dura Ace stem but I imagine that the set screws are required to keep the cone wedge from being unscrewed when tightening or loosening the stem when installing, adjusting or removing it. It’s a bit hard to say for sure but the smaller threaded section of the bolt appears to be “left hand threaded”! Have you tried to remove the cone wedge by turning it clockwise?

malcala622 

Its possible the WD40 isn't breaking down the possible corrosion between the threads. Maybe some PB blaster will help a bit more.

merziac

@70slibrarymusic

The set screws need to be in place, I was confounded by one of these and found the explanation buried somewhere but didn't save it.

They actually keep it from getting really stuck when installed, they are like limit screws, never did fully understand but it did eventually make sense.

70slibrarymusic

I have and it is quite stubborn. Doesn't budge at all whether tightening or loosening. Forgot to note that it's actually in a position where it is only partially loose, had to really put some elbow grease to get it off.

My theory is something could've lodged within the threads because as I was taking it off, I was able to turn the bolt quite easily until it just got stuck like this. Would PB Blaster be effective if that was the case or would another penetrant be more apt?

merziac

70slibrarymusic

I was thinking of taking them off because at this point, the stem becomes fully wedged into the fork without even being halfway thru the slots where those limit screws would stop the expander. Do you think it's possible to find a replacement for this part only?

merziac

If you take/leave them off it will get stuck in the steerer, the threads work against the set screws in the slot to force the expander loose, with out them the wedge will not loosen once tight.

I know it is counter intuitive but all that is likely working correctly, I would but it back together and test fit with lots of grease in and out to see and understand how it works.

Look up the Shimano instructions online for the specific one you have for a little more info.

masonv45

Clamp the wedge in a vice (with wood cushions) and use the double/nut technique to turn the bolt. Also might help to heat up the wedge with heat gun.
From the type of metal I see from the pictures, I think one of the wedge threads stripped and now that stripped piece of metal has bound up the threads on the bolt/wedge.

merziac

@70slibrarymusic

Forcing this into submission will likely damage it and possibly make it useless or worse like stuck permanently.

Like I said, mine was stuck in the steerer initially and I got it out, thought the same as here to begin with, stopped when I got to the vise and figured it out enough to realize it was ok and that I needed to stop forcing things.

Didn't understand it totally but enough to not butcher it and to make it work.

sovende

Another thought is that the set screws have damaged the threads .
I appreciate that the Dura Ace component line up is near or at the top of the Shimano “food chain” but too me, it sacrifices function for form. The weight savings and lack of visible fixation bolt heads certainly have their appeal but the “engineering” seems to have drawbacks. Aside from the issues experienced by the OP, I see that a special (long) hex wrench is necessary (but included with the original stem.) I’m not sure if the conical, internal wedge that expands a relatively thin (at least at the bottom) stem quill is as sturdy as the more traditional external wedge that utilizes a much thicker stem quill.

shoota 

Well now there's an important detail. Sounds like you forced something past its design. When I got my stem someone told me to leave the screws in and to NEVER overtighten or overlossen, whether in the fork or not. I think I see why now, although I have to admit I don't understand how these stems work yet.

Doug Fattic 

I recommend that you listen to Merziac and do not use more force to try and undo the problem you created yourself by using too much force. Shoota is right, you forced something beyond its design. They work nicely when you follow instructions and realize that the soft aluminum wedge dislodges itself from the stem when you turn the stem bolt counterclockwise. It will loosen without hammers or heat. You have to be careful not to turn it too far or something breaks. The problem comes when one assumes it is like other stems and it is not. One can also get in trouble when the stem is stuck to the side of the steerer even though the wedge is free from the stem.

There are 2 sets of threads on the stem bolt. The lower threads holding the conical wedge are left hand threads (as already mentioned). You have to be really careful with that conical wedge because it was made out of aluminum instead of steel. That means it can easily be damaged. Here are instructions I found in an old DA stem box.

jdawginsc 

Were these sturdy in the steerer? Not sure I understand how these work well.

merziac

Welcome to the club, you wanna be the Prez?

merziac

Pretty sure they were, never seen an issue until you take them out, then the fun starts.

Doug Fattic 

They worked fine. I used one on my primary bike for years. The idea is that those 2 little set screws in the conical wedge kept it from turning when the main binder bolt is turned. Because the binder bolt hole on inside of the stem itself is stepped (to kept the binder bolt from rising like would happen in a normal stem), it pushes the wedge away from the bottom of the stem freeing it. It was not necessary to use a hammer to hit the binder bolt to free the wedge. Because the binder has two sets of threads going in different directions, it can be counterintuitive how to use it. Those familiar with traditional quill stems can get into trouble if they treat a Dura Ace the same way.

Looking at the original picture on this subject thread, it appears that it was just as it should be. Perhaps the OP can tell us differently. A bit of grease everywhere (maybe with nozzle or pressure help) while it was completely assembled after he did a nice job of cleaning it and it should have worked fine.

70slibrarymusic

This was actually a problem I also had to deal with.

Well, I think it's that right there. I think the problem was caused by my clueless caveman instinct to hammer the bolt. Another lesson learned the hard way. Wish the previous owner told me about this although I doubt he would've knew anyway because it seemed like the bike hasn't been taken apart for a decade or so.

Any ideas where we go from here? Or do I just look into getting a new stem? I actually have a nice little Sakae Ringyo quill lying around that would fit well with the SR bars it came with.

shoota 

Another important detail!

shoota 

I just installed one on my Tommasini and it's working well. I had to order new T-handle hex wrenches though, that expander bolt sits wayyyy down there.

Doug Fattic 

In your defense, it isn't obvious how they work unless you read the instructions. And what real man ever reads instructions? I was actually rushing around to find those instructions before you did what most others would do and treat it like a normal stem.

I'm not sure of the innards on your stem. I think you have unscrewed the bolt from the head that is still inside? Those 2 little side screws keep you from doing that but they are out now. So try screwing the long bolt back into the head (which is still in the stem). Once you screwed it up tight, now you can screw in the little side screws into the conical wedge. Perhaps now you can gently use some elbow grease to see if the long bolt will turn in the wedge.

Here is a picture of a Dura Ace stem and the 2 tools that came with it. The hex tool isn't all that long so a normal one will probably work. The cheater bar that goes into the short end of the hex tool has been a standard tool I use all the time for uses other than working on Dura Ace stems.


You not only need these tools to work on this stem but most of us need the instruction sheet too.

repechage

Finicky design.
display it, go Nitto or something else.

like resetting the boobytrap otherwise

70slibrarymusic

I unscrewed the hex bolt by removing the limiting screws and turning the exposed cone expander from the bottom. I think I'll do one last attempt at soaking just the part of the bolt with the cone expander. Definitely not a good item to deal with for a first build. Though I did learn a lot through this, nothing like learning through trial and error!

Thanks to everyone, really appreciate the responses.

Doug Fattic 

I'm going to assume that the problem is that the wedge nut is stuck on the bottom of the binder bolt? It might be stuck there because of your elbow grease and force. It is also possible that gunk has frozen it in place. The product PB Blaster is designed as a penetrating lubricant to free stuck nuts and bolts. You might try that.

If indeed the problem is a stuck wedge on the bolt, you will want to somehow carefully hold the wedge while you are turning the bolt. That may include putting it all back together and letting the slots in the stem itself keep the wedge from turning as the blot is turned. The ø of the biggest part of the conical wedge is just over 3/4". It is aluminum so it is easily damaged. If it was in my shop and I wanted to save an expensive stem, I would drill a hole (with a hole saw) between 2 pieces of wood. I would place the 2 pieces of wood in a vise to hold the wedge in the hole securely. Than I could use greater force to remove the bolt. Remember that the bolt has a left hand thread on the bottom treads so to loosen the bolt from the wedge, you will be turning the bolt clockwise.

To others not the OP: These stems work well once you understand how they function and don't go beyond their limit tightening and loosening.

sovende

As the old saying goes, “Good judgement comes from experience , experience comes from bad judgement . Nice bonus of this forum (and many others) is that we get the benefit of the experience of others regardless of how they obtained it .