June 16, 2010

Fixing Wobble in Dahon Folding Handlebar

Problem: The hinge where the handlebars fold down from the frame has a slight wobble as if the locking mechanism has a little play. The locking mechanism includes a pad on the handlebar-side of the hinge, which has several allen key screws.

Short-term Fix:
Building off the shim concept of break_2_fix, consider the following (it's working for me):

Material: Get some heavy foil, just a little 3 x 3 square is fine... heavier the better, within reason.

General Concept: Create a foil shim to mold over the locking mechanism to make it have a tighter lock. Warning: This is a bit crude, so use some good judgment in adopting this solution.

Tools: scissors.

Setting: Observe the part of the hinge attached to the handlebars. In the center is a silver metal pad that has the allen wrench screws on top and on one edge. This is the pad that moves to lock the handle bar. The part of the pad that is arch-shaped has a lip on it. That lip slips into a grove on the part of the hinge attached to the bike frame when locking.

Process: Cut a 3" x 3" square of foil. Lightly press the foil over the "pad" referenced above to create an impression of the nearly square-shaped pad (square-shaped except for the arch along one edge).

Use the scissors to trim the foil to within about 1/8-1/4-inch of the outline of the pad that is now molded into the foil.

Carefully mold the remaining foil over the pad. Fold it down firmly on all edges taking particular care to fold under the part on the arched lip of the pad.

Extra: You can use a blade of the scissors to carefully cut little half-moon slits in the two holes on top of the pad where the allen wrench screws are; carefully fold the edges of foil, at the slits, down into the holes to improve the foil's grip to the pad (I considered glue, but.. doesn't seem necessary).

Trial: Carefully lock the handlebars into place. If it seems too tight, don't force it. If too loose, you could try two layers of foil or other refinements.

My outcome seems to be just right. Locking it into place seemed, if anything, to make the foil better molded to the locking pad mechanism.

Good Luck


1 comment:

Yuriy Akopov said...

Hi, I've stumbled upon this post while looking for the solution of the similar problem.

Before I used a piece of plastic in a similar way you described to get rid of wobbling, but actually all you need to do is to tight the screw in your handlepost (10 mm wrench needed).

The procedure is very simple and obvious and is also described in the service guide available on Dahon website.