Disclaimer: I'm brand new to bikes. At the moment, with a little weight on the handlebars (like using them as a stabilizer to mount the bike, or standing up on the pedals), the handlebars rotate about this axis. I thought "Oh, sure, I'm a noob. I just didn't tighten this enough." And so, I tightened it some more, and only saw minimal improvements. Now I've tightened it as much as I physically can with the Allen wrench, but it's still not stable enough. Is there a trick to this I may be misunderstanding?
by Mobius1424
20 Comments
If you loosen it back up and put a thin metal shim in there, it will clamp down tight
I would put a rubber shim in between so the clamp can get purchase down into it and the clamping force of the rubber against the metal bar will keep it from slipping in that direction.
Edit: I’m totally willing to believe that I’m an idiot and this won’t work. So I get the downvotes. Can anyone tell me why this won’t work or why I’m wrong? Just curious. Left to my own devices I definitely would have tried the rubber shim.
Put a old tube rubber piece between there and then tighten it
It has plenty of gap in the stem to go tighter. I would replace the button head screw with a hex head screw and use a real wrench to torque it down. Your little hex key probably doesn’t give you enough leverage.
I had a job building those exact cruiser bikes, the metal is inexpensive and will stretch. Find an impact driver or very strong person and close the gap behind that bolt
Not throwing shade, I love when new people start riding, but this is the downside to cheaper bikes, they are not designed to last very long because of the materials used and sometimes require a lot more force to make them rideable over more expensive ones
Use a little carbon install paste (not just for carbon). It’s basically gritty gel and provides something between the metal to “bite” into.
It will scratch your finish (not a problem inside the clamp) so just make sure to gently wipe off any extra
Grease the threads on the bolt, and maybe even a dab under the integrated washer on the head of the bolt against the face of the stem. Should allow you to get it a little tighter without a tremendous amount of additional force.
Grease the threads before you tighten it. You want to stretch the bolt, not bind the nut.
Get a bigger wrench (more leverage to go tighter)
Is the stem ID and handlebar OD different? Could be 26.0mm stem and 25.4mm handlebar.
I dislike single bolt clamps of any sort because there is so much to go wrong with them. As you tighten the bolt it comes to a point where the metal tab the head is pressing against is no longer perpendicular to the bolt.
If you keep on tightening, the sides of the hole through the tab will start pressing against the sides of the bolt, pinching it way before it is tightened far enough.
Any thread in a bicycle should be greased. All threaded holes on cheap chromed parts should be chased with a tap.
Get a bike from a bike shop and not a big box store.
uninstall
Get a file on it and rough it up.
reinstall
Impact driver will solve this
It’s not ideal but you could try putting a turn of masking tape or similar around the bars before tightening the clamp.
Beer can works as others have suggested. I like aluminum foil as you can run as many layers as you need. That and a good ugga dugga
Assembly paste
It looks like that screw threads into a blind hole (i.e. it doesn’t go all the way through) Make sure you aren’tbottoming out the screw. If you are you’ll need a slightly shorter screw (or if you want to roll the dice, put another washer in there)
Single bolt stems on Dutch bars have a terrible movement problem, it is because the loading is irregular on the bar.
If you can get a two bolt, or even better a 4 bolt stem, it works much better
Check serration on handlebar and clamp, have you overtightened it and threads have slipped or the bolts are not torqued to specification