Bicycle Mechanics - Wow - What is going on with this frozen headset/fork/stem combo??

http://i1015.photobucket.com/albums/af273/4oncraigslist/670701c6.jpg

I'm trying to disassemble this frankenbike for parts.

It's an old Lotus, but the previous owner swapped out the original Tange fork for a longer Reynolds 753. He also put on an aheadset, and as you can see in the picture, there are still some threads exposed.

I am desperately trying to get the stem and handlebars off, but loosening the bolt on the stem wont release it. I don't have experience with aheadsets. My first instinct was PB Blast and twisting it out, but so far I haven't had any luck. I figured I would come here for advice before making a serious mistake.

If you have any idea what I should do, please let me know! Thanks so much.

http://i1015.photobucket.com/albums/af273/4oncraigslist/670701c6.jpg

I'm trying to disassemble this frankenbike for parts.

It's an old Lotus, but the previous owner swapped out the original Tange fork for a longer Reynolds 753. He also put on an aheadset, and as you can see in the picture, there are still some threads exposed.

I am desperately trying to get the stem and handlebars off, but loosening the bolt on the stem wont release it. I don't have experience with aheadsets. My first instinct was PB Blast and twisting it out, but so far I haven't had any luck. I figured I would come here for advice before making a serious mistake.

If you have any idea what I should do, please let me know! Thanks so much.

That's not an "Aheadset"... "Aheadset" is Dia Compe's brand name for their threadless headset. Yours is obviously threaded. If it says Aheadset on the head cup, well... that's definitely a Frankenbike!

You have loosened the stem's wedge bolt. As implied, there's a wedge at the bottom. All you need to do is tap the top of the bolt with a rubber mallet and it'll break free. If it's been there a while and rust and corrosion has worked its way into the interface between the stem and steerer it may require penetrating oil, leverage, and perhaps destructive removal.

Don't worry about breaking anything. The stem is not associated with the headset at all on a threaded fork. It is only in contact with the fork's steerer tube. Once you tap the wedge loose, do whatever you must to loosen the stem. A big hammer may work.

There are also chemicals you can use, if the aluminum stem has corroded and bonded itself to the steel steerer. I'm not familiar with them though.


That's not an "Aheadset"... "Aheadset" is Dia Compe's brand name for their threadless headset. Yours is obviously threaded. If it says Aheadset on the head cup, well... that's definitely a Frankenbike!


Looking at an Aheadset in a drawer here, the font looks suspiciously similar to that of the photo. I'm not sure how it would work, but that might actually be a threadless headset!

For the sake of confusion: threaded "Aheadset" (http://www.aheadset.com/bicycle-headsets?p=TD.1)

I'm not sure how it would work, but that might actually be a threadless headset!

Wow I have never thought of that, maybe the top cup is threadless and since the fork was threaded they just mounted 2 locknuts on top of the threadless top race? I only see one lock nut in the picture, maybe the other is hiding. Anyhow, yeah tap that bolt down and twist that stem free! Unless someone tightened it so hard that it expanded your steertube, it should break free.

I hit it with a rubber mallet. Perhaps a real, direct hammer shot is what is needed. I believe it said Tange on the top of the headset, and aheadset on the bottom. Is this possible?

hit the bolt down with a hammer.

Stop: Hammer-time

If the hammer doesn't work right away, try to drip some Liquid Wrench into the gap between the stem and the steerer tube and come back in about half an hour and hit it again.

Please note that you will need to brace the fork at the crown with some support if you will have to hammer hard on the stem assembly. You do not really want to transmit all that hammering force down the fork legs and dropouts if you want to save it for another project or just avoid damaging it. I 'd use a legnth of 2X4 wood under the fork crown between the fork legs and support it on two chairs or horses. Doing so might also help prevent damaging your headset bearings and races if you want to reuse the headset again. specially if you were hold on to the frame with the fork off the ground while you were hammering.

Chombi

Thanks for the tip, Chombi.

Yeah, leave the wheel on the fork so the tyre cushions the blows.

I prefer to put an allen-bit socket into the stem-bolt before hammering it down to free the wedge. Easier to get a square blow in-line with the bolt that way. Using an L-shape allen key always ends up causing some of the force to go where you don't want it.

I hit it with a rubber mallet. Perhaps a real, direct hammer shot is what is needed. I believe it said Tange on the top of the headset, and aheadset on the bottom. Is this possible?


Yes. Definitely a Frankenbike. If the rubber mallet didn't work, hit it with a steel hammer. The stem looks pretty beat anyway- I don't think you'll hurt it any more whacking it with a hammer. The frame and front brake look worthy of preservation, though.

I have a 3lb leather mallet for just such occasions - also a steel hand-sledge wielded lustily against a small scrap of 2x4 atop the offending wedge-bolt will work.

Stop: Hammer-time

http://i584.photobucket.com/albums/ss286/brian3069/298tio.gif

A rubber hammer isn't good for this job at all. You want to create a high force on the wedge, rather than giving the whole bike a slow, heavy hit.

1. Get yourself a long steel bolt metric 8.
2. replace the aluminium bolt with the steel bolt. Make sure you got the thread at least 4-5 turns in.
3. Whack it hard from above with a light hammer. No rubber, no wood between. If you use a light hammer, you dont need to worry about bracing the fork crown. The frame's inertia is enough to counter the blow.
Of course bracing won't do any harm and might make you feel better. ;.)

Sorry to bump an old thread, but I just wanted to update and say that I got the stem free, and will be replacing the wonky headset and passing the frame onto a shorter friend.

Lots of great tips here, thanks everyone for your help.

next time, do regular the maintenance , a few minutes ,
a thin bit of grease on the stem and wedge bolt saves the grief
when they rust and corrode together.