9

I have a second hand Peugeot road bike. I noticed the handlebar was rotating on its own, unscrewed the screw, straightened the handlebar and found out it won’t screw back. Later I found out the screw is a bit deformed which is probably the reason it won’t screw back.

the screw.

Went to my local hardware store and they don’t have this screw. Anything I can do? Are there still screws like this one?, cause these bikes look pretty old.

Improve this question
1
  • 1
    When you unscrewed the bolt the wedge dropped down into the fork. Without the stem in place see if you can use the bolt to engage the dropped wedge. Otherwise, turn the bike over and try to shake it out. (The slightly bent bolt is semi-normal.)
    – Daniel R Hicks
    Commented Jan 5, 2020 at 19:14

3 Answers 3

Reset to default
24

That’s a tension bolt for a quill stem I think. Is there a wedge shaped piece floating around inside the fork now? You can fish it out with that bolt or maybe flip the bike upside down.

enter image description here

The last few mm of the bolt look stripped which may or may not be an issue. The small bend in the bolt shouldn’t be an issue.

Try cleaning everything then reinstalling with a dab of grease on the threads and the interface between wedge and stem. Don’t over tighten the bolt.

You can buy a new quill stem at your local bike store or online for not much $. You’ll need to get the right size for your fork diameter.

Improve this answer
1
  • I'd say the stripped part is the main issue. For one, they aren't able to latch onto the wedge because of the missing threads, and for two, the missing threads are likely due to over tightening at the point where the wedge would normally engage. This means that the wedge isn't applying pressure and causing the loose handlebars. The OP definitely needs a new bolt. I doubt they can get the wedge to tighten or even install, once it's out of the fork post.
    – computercarguy
    Commented Jan 7, 2020 at 19:13
15

Older bikes have what is known as a quill stem. The stem telescopes inside the fork steerer tube and is held in place with a wedge. The long bolt you removed threads into the wedge. When the bolt is tightened the wedge is pulled up.

What you should have done is loosened the bolt, aligned the bars and re-tightened the bolt. With the bolt removed the wedge is not longer attached to the stem. It's either dropped down lower in the head tube or is stuck where it was. You should be able to get the wedge out. Out the stem and look in the head tube with a flashlight. It may simply drop out if you turn the bike upside down, or you can tap it loose with a hammer and long screwdriver or the bolt itself.

When you get it out, reassemble the stem out of the bike. You want to clean and lightly grease the bolt, stem and wedge to prevent things corroding in place in future. With the bolt loose, reinstall the stem into the bike, adjust stem position and tighten the bolt.

The bend in the bolt might not be an issue. I'd be more worried about the state of the threads and the ability to tighten the bolt up hard enough to lock the stem in place.

There are lots of YouTube videos on all aspects of bike mechanics. Here a good one on quill stems from Park Tool.

Improve this answer
2
  • I tried putting the bike upside down and nothing drops. I am able to screw it but not all the way down, at the point I can just twist it infinitely without any change. Which is why I thought the bolt was the problem.
    – Mikey Hasson
    Commented Jan 8, 2020 at 15:16
  • 1
    The bolt is probably not engaging in the wedge, which is why you need to get the wedge out and reassemble the stem and check it all works. Have a look in the steerer tube with a flashlight. If you take the front wheel out you can probably tap the wedge out from the bottom of the steerer tube.
    – Argenti Apparatus
    Commented Jan 8, 2020 at 16:07
1

This thread allowed me to locate the wedge (that fell down into the fork) - bike turned upside down and a tap from hammer dislodged it. Thanks to those who took the time to provide the information - much appreciated. I can head off for a cycle now.

Improve this answer
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.