Tube extension doesn’t work

[marcs2000]

i recently bought a steering tube extension to have my handle bar raised by about 10cm. The extension came with a very long screw going through the center of the steering tube and 2 screws to tighten on the outside. I cannot get the tube to stay fixated even when i tighten all 3 screws super tight. The handle bar still moves around when applying some force.
what am i doing worng?

 

[cougie uk]

I've not seen these extensions. Do you have a link to the item ?
Can't recall seeing a bike with one ?

 

[marcs2000]

https://www.rutlandcycling.com/part...XdkXsB6ncmpTupjzDOPdpoyxy_ctZwvwaAqQ4EALw_wcB

does that help?

 

[ColinJ]

You shouldn't tighten the long central bolt 'super tight'. That needs to be tightened just right - tight enough to stop the steerer clonking about, but not so tight as to jam up the headset bearings.

As for why the handlebar moving... Does the handlebar stem stay fixed relative to the stem raiser but that moves on the steerer tube, or does the stem raiser stay put on the steerer tube but the stem moves on the raiser?

 

[cougie uk]

Aha. Clearly something is moving but you need to work out what it is.

Is it the stem on the extension post ?

Or is it the extension post on the fork ?

When you say applying force - you just want the steering secure - there's not much to stop a wheel turning unless you're doing some pretty gnarly stuff off road?

 

[ColinJ]

Aha. Clearly something is moving but you need to work out what it is.

Is it the stem on the extension post ?

Or is it the extension post on the fork ?

I just said that!

Ok, I just wrote that...

OFFS, I just typed that... pedants!

 

[numbnuts]

View: https://youtu.be/ZCoxnnvFl1Q

 

[marcs2000]

Thanks guys. I did see that video by Jason and I am doing pretty much exactly what he says but problem still persists.
In my view, it is the extension that is rotating around the tube. Its not rotating all freely but if I apply a bit of force, it does move.
THe only thing maybe could be that I am tightening the middle screw too tight.

 

[ColinJ]

How much force are you applying to create that movement? (I assume that you are holding the front wheel between your legs to stop it moving sideways?) Can you get that movement easily by pulling one-handed on one end of the bars? That should NOT be possible. If you have to use both hands, one pushing hard on one end of the bar, and the other pulling hard on the other end, that doesn't sound worryingly loose since that is way more force than you would ever exert when actually riding the bike.

Make sure that the circular cap on the top is pushing down on the top of the stem NOT on the top of the steerer tube. It is not there to hold the stem on, but to control how hard the stem is pressing against the headset so that the bearings are loaded properly. As he pointed out, you need to make sure that both of the bolts on the stem are below the top of the steerer but that might mean that the top cap isn't pushing down on the stem itself. If that is the case, add a short spacer above the stem which the cap will then push down onto the stem.