Mountain Bike Forums

Hi, this is my first post. I recently bought a mountain bike online which arrived partially dis-assembled for easier delivery i assume, anyway the handlebars were fixed to the stem, but i had to fit the stem to the steering tube myself. This was my first time doing this, but it seemed straight forward enough. A bolt running through the stem attached to a wedge(nut type thing with ridges), so attached and tightened it all thinking it should be fine, went for my first ride today and 10 minutes in the handlebar became loose and mis-alligned! i quickly braked jumped off and straightened tried again samething happened only worse than before, so i gave up and started pushing it home. I noticed the handlebars becoming looser and looser as i pushed it until the complete stem with all attached slid right out the steering tube! =[ i thanked god it didnt happen while i was traversing traffic at speed. Ive just attempted to fix and tighten everything back up, but i cant see any difference between what ive done now and what i did upon first putting it together im worried about riding it and need some info from the experts

Thanks

Hi Shanny,

Sounds like you have a quill stem attaching your bars to the bike.

You may find the answer you need on this link: http://www.sheldonbrown.com/gloss_st-z.html#stem

Look down the page for an explanation of how the stem works. It seems likely that you may not be tightening the central bolt enough to lock the stem and the wedge into the fork steerer tube.

Be careful to ensure that the steerer part of the stem is correctly inserted into the fork. There is a mark showing the minimum insertion needed to ensure a safe connection.

Hope you get your problem sorted out and can get back cycling safely soon.

Regards

Incognito1