Loose stem problem for Downtube 9 front suspension

[s47miller]

I recently got a Downtube 9 front suspension bike, and am having a problem with the handlebar stem stability. There is about 1cm of "play", or front-to-back movement, which makes the bike feel unstable to ride. Most of the movement comes from the hinge joint, with some also coming from the telescoping quick release.

I've tightened the folding joint quill bolt and both quick releases as much as possible, but there is still this movement. It is not only unstable, but seems that the movement will eventually weaken the stem and cause it to fail. Any ideas on how to fix this?

(I saw another thread with this same problem - calling a stem "stim", but the link to Dahon website with the "answer" is no longer accessible. Thanks for helping.)

[jur]

The Downtube stem riser is completely different to the Dahon's.

You could contact the Downtube owner, or you could post a pic detailing exactly where the play in the hinge is. The hinge, although a failsafe design, can have some play if the hinge pin fits loosely. If that is the case, remove the hinge bolt and slide the pin out. A shim cut from a soda can with scissors may be thin enough to fit in and reduce the play.

[Archer-ca]

Another Forum Member came across the same situation and implemented the 'shim' solution as mentioned by JUR,

http://www.bikeforums.net/showthread.php?t=388071&highlight=

Hope it will work out for you too,

Norman

[Pine Cone]

There is about 1cm of "play", or front-to-back movement, which makes the bike feel unstable to ride. Most of the movement comes from the hinge joint, with some also coming from the telescoping quick release.

I've tightened the folding joint quill bolt and both quick releases as much as possible, but there is still this movement. )

Without seeing the bike it is hard to tell, so here are some things I would check...

Have you taken off the stempost and checked to see if the internal stem is tight? I have had mine loosen up which gave me some of the symptoms you mention.

Can you twist the stempost/handlebar group around any if you lock the front wheel with you feet and legs and twist the handlebars?

Is the hinge bolt tight?

Are you sure you have the quick release on the stempost is tightened properly? I have seen people think that the QR lever is just a screw, not a cam with a screw. I bet you have it right, but I have seen people mis-use them before.

Have you contacted Downtube? If there is a manufacturing problem Yan is good about fixing warranty problems.

-Good luck!