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View Full Version : Mechanic stuff: stuck stem unstuck!


wsbob
10-05-2009, 09:15 PM
The following is just my rather lengthy account of having been presented with an aggravating bike repair problem. If you happen to be one of those folks that find what I have to say to be of no value or particularly annoying, you'll probably want to stop reading right now.....:cool:.

A couple months ago, I realized the handlebar stem on my trusty Trek 560 was stuck fast. To those of you that haven't had or heard of the problem, this can happen with the old style handlebar stems; aka quill, gooseneck, threaded (as opposed to 'non-threaded' which most new bikes seem to have today, and that are designed to not get stuck)...when the aluminum of the stem, due to exposue of moisture and salty sweat, fights the steel of the fork's steering tube that it fits into very closely.

Yearly or bi-yearly removal and light cleaning of the inserted part of the stem avoids the problem. I figure a lot of people, for one reason or another, probably aren't aware of the potential for this problem. Then it happens and like me, they find themselves in big trouble.

Once I had a sense I was dealing with something serious, I started asking questions from bike mechanics I talk to. Also did a lot of online research. Lots of good info out there at BikeForums, Road Bike Review, Sheldon Brown, but this problem of corrosion can be so severe that people have to resort to drastic measures such as cutting the top of the stem off and using a hack saw blade to cut the stem out from its inside. I thought I might be having to do that.

I have very little bike mechanic experience, very few bike tools, a bike stand that's barely usable. The family though has a shop with car tools and a mechanic vice. My initial efforts to apply torque to the stem to free it were very timid out of fear that I'd damage the fork. Didn't put it in the vise at this point...just held the bars stationary with my legs...used the handle of a hammer in the fork tubes close as possible to the head tube to apply force. Later...used a baseball bat at the same point. Didn't free it up.

In trying to solve resolve the predicament, people have come up with and resorted to extraordinary measures to free stuck stems. One of the most extreme I came across, was a guy that turned the bike upside down, sealed up the stem tensioner bolt hole and filled the inside of the stem with commercial drain cleaner. I forget if it was days or weeks to do the job, but what it did was to almost completely dissolve the aluminum stem. Guess it's not supposed to hurt steel....but I couldn't see myself trying that approach.

Ultimately, I decided that before I cut the stem off and hack-sawed from the inside of the stem out, I would try the 'penetrating oil combined with torquing on the handlebar/stem route' first. What oil to use? PB Blaster gets consistent thumbs up from most everyone that uses it; mechanics, DIY'ers.... . That's what I used.

On my bike, the stem tensioner bolt came out....no problem, and the jam nut was free too. I put the stem bolt back in...sealed it up with duct tape...turned the bike over....sprayed a bunch of PB Blaster into the opening in the bottom of the fork...into the steering tube until it rose over the level of the jam nut. Left it alone for 2-3 weeks except to check to see the level was up and to try tap the stem a bit tip (that's supposed to help the oil penetrate). That I could see with the flashlight pointed into the steering tube, over 3 weeks, the level of the oil never dropped appreciably.

Went over to check on it today. After all the thinking about this problem I've been doing, today I realized I had to get stem or fork more stabilized if I was going to be able to effectively apply torque. Went to the vice....used rags and boards to clamp the stem.

Baseball bat wrapped in rags between the fork blades next to the head tube....carefully applied pressure. Nothing for the first 4-5 tries in each direction. Fibers in the bat crunched....at least, that's what I was hoping it was. Then suddenly....movement of the fork about one or two degrees.... . Very resistant, but kept moving it in either direction. Very gradually, the distance it moved increased. Stopped after 20-25 pushes, to let the parts inside cool. Lots of friction going on in there.

Realized I was twisting the forks when I should be twisting the stem with the handlebars so that I could pull up while twisting. Took me a few minutes to figure out how to hold the fork in the vise without messing the fork up; again...cloth and boards between the delicate stuff and the jaws of the vise.

More hard exertion to twist from side to side....gradually 10 degrees....15, 20....now it's getting loose enough so I can start to exert upward force....Yes!....stem started to slide up. Didn't take more than about 5 minutes after that.

I stopped working on it for today at that point. Inside of the steering tube is gunky with rust. I'm thinking of ways to best clean it out to prepare for the new stem.... emory cloth on dowells attached to an electric drill? ...I'll figure out something. Success comes especially nice somtimes. I'll be riding my old faithful bike again before long!

handfab
10-10-2009, 02:19 PM
Glad to hear you didn't have to resort to drastic measures. I've experienced many stuck stems and seat posts as a mechanic.

One last tip I hope you've been told: put a thin film of grease on the stem, the wedge and the threads of the bolt. This will insure it won't seize up with rust in the future.

wsbob
10-11-2009, 12:41 PM
handfab, thanks for the note about greasing the stem and related parts. Haven't yet installed the the different stem I'll be using. Rather than the jam-nut that the stem I removed was equipped with, it has the expander type nut.

I actually prefer the jam-nut type, thinking it's going to be less inclined to get stuck. Also it just seems as though the jam-nut style would fix the stem against the inside of the steering tube better than the expander nut style in a way that would minimize side to side movement when weight is put on the handlebars. Buying used...and the fact there aren't so many threaded stem choices out there anymore, this is what I've got . It's a very nice looking TTT stem though... . Hope it works good. If not...I'll have to get something else.

I believe I heard the bike shop guy (10 years wrenching experience) tell me I could install the expander nut dry, with only the addition of anti-seize compound to the nut and inside of the stem to avoid the grease drying out and gumming up (still using grease on outside of stem between it and inside of steering tube). I haven't reasoned out whether anti-seize would be better here than grease. Either might work if, in future, I do the other part of the preventative maintenance that's supposed to avoid stems getting stuck: Remove, clean, re-install threaded stems once a year.

Grease on the outside of the stem between it and the steering tube makes more sense to me there than anti-seize.