Stuck Stem
 

Would anyone know of a good way to remove this remnant of a stuck stem (that was cut off) from inside of this fork (without ruining the fork)? It's aluminum inside of a steel steerer tube. I've been carefully hack-sawing and Dremeling at this piece for a long time and I feel like there has to be a better way.

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And for what it's worth, I took it to a bike shop many weeks ago when the stem was still whole and they couldn't get it out, so I've just been spending some time here and there trying to surgically remove it.

Have you tried driving it out from below?

As an aside, there's not many bike shops around anymore that can work on anything without a threadless stem....


verktyg :50:

Chas.

Stick it in a bucket of lye or drain cleaner and let it eat up the aluminum.

+1
I have soaked forks with stuck stems in them in Oxalic Acid & also in Evapo Rust with the same results, after about two weeks the stems came right out. Evapo Rust is safe for aluminum so it doesn't eat at it like Lye or OA, but still worked just as good.

Glenn

Thanks for the tips. I'll try soaking it in something.

It did get a thorough dose of PB Blaster while it was still whole and stuck in the headtube, didn't occur to me to try the chemical option again.

You could also try freezing it. Because aluminum expands and contracts at a greater rate than steel, you may have some luck.

Something else to try would be to start drilling it out, using progressively larger bits until you can fit a hacksaw blade in there. Then carefully start cutting it. A couple good whacks with a hammer and drift from the backside should take care of it.

EDIT: You could also try heating it up with a torch or heat gun. In working on cars in the past, sometimes just an application of heat and subsequent metal expansion will break whatever bond is between two frozen parts.

Didn't know about using lye for this. Interested in your opinion on this approach for a seized stem in a fork that's still on the bike. Could it work if I seal off the stem end, fill the steerer tube with oven cleaner and let it sit? How long do you think I'd have to wait?

Oven cleaner isn't strong enough and is usually a modified ammonia. Lye based draine cleaners can harm paint. For stems, a few days of repeated penetrant like PB Blaster or the WD 40 equivalent, qnd a rap with a mallet or hammer downward are usually enough to free a stem.

A machine shop with a drill press can bore out most of the aluminum ,

then you chip out what's left and then the wedge will fall Out. from below that is what you will Hit.

You can also take the blade out of the hacksaw frame and saw thru the aluminum vertically in a couple places

then like pie wedges the AL tube will come out.

Thanks oddjob. I've already gone the PB Blaster route, keeping it full over a weekend, but no success. My next step was to try the same with acetone/ATF mix.

Use a half and half mixture of acetone and transmission fluid. Much better than any penetrating oil including kroil.

The last two stuck stems I had ( Centurion Le Mans & Trek 460 ) were removed while the forks were still on the frame, I just turned the bike upside down. The Le Mans I used Evapo Rust and the Trek I used PB Blaster and a little Evapo Rust mixed in, I would tap on the fork with a soft face dead blow hammer like a tuning fork and let it vibrate. Both took about a week & a half but it was so cold I wasn't working in the shop and would check on it about every two days.

Glenn

Here's how I removed a totally corroded in seatpost on a Tri bike:

Starting with cutting the seat post off leaving enough materiel to grab in a bench vise, I started cutting a split in the post with a jab saw and finished the cut with a folding brush saw.

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After an hour or so I finally broke through the aluminum at the bottom of the post. It was not only electrolytically welded to the inside of the seat tube but rusted solid (rust expands/grows making removal more difficult.

Word of caution... make sure that you're only cutting the aluminum and nut getting into the steel tubing. That's why I start at seat lug split in the rear. I can cut down ~25-30mm to get the deeper cut started.

I was finally able to remove the post by crushing it to break the bound to the seat tube. Reaming and honing afterward cleaned up the seat tube ID.

A simple glop of grease inside the seat tube and on the seatpost would have prevented this....

FLI (Friggen Lazy Idiots) :troll:

The grease trick works with stems too!


Addendum... While Centurion Ironman bikes came stock with them, who in their right mind would use a fluted seat post in a triathlon bike where water is going to get down into the seat tube??? I guess T-letes don't have to be very snart!


verktyg :50:

Chas. The Impaler

i've done exactly that with the steerer still in the frame, but i wonder if using acid would be quicker now that the steerer is out and it would be an easy dunk.

I had to do this to an aluminum bottom bracket sleeve stuck in my Fuso.

It still required screwdriver and hammer to get those pieces out.


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Heat. Heat the steerer tube up with a heat gun.