Wilts1969

HI,

I'm hoping someone can help me solve an issue I have with a recently purchased used Dahon MU P8.

The issue I have is that the telescopic folding steering column doesn't seem to fully tighten, so when using the bike the steering column slides down to it's lowest position. The other issue is it appears loose on lateral movement, I can turn the column about 10 degrees to the right when holding the front wheel. When trying to turn the column to the left with resistance it doesn't go off centre, which is what I would hope turning to the right would do, but evidently not.

Can anyone suggest a solution to the problem. It was only purchased to use as a folding bike when using our campervan.

If it helps the serial number is D706702403.

Many thanks

Duragrouch

Some Dahon telescoping handleposts were subject to a recall. You should check online, there are clues for that in terms of serial number and looking for a letter on the post when unfolded. Warning: If needed, replacement of the handlepost base is fast; Have them (Dahon dealer) do that with you present, and do not leave before checking that the new handlepost does not tilt left or right (from rear view, make sure parallel with extended seat post), I have received defective handleposts when replaced under recall, did not notice until home, they had already trashed my old part.

Besides that, the telescoping clamp should lock things in telescoping, you might have to adjust the screw on the other side of the lever that does the clamping. Also, make sure both tube clamp surfaces are clean, no oil or grease.

I cannot recall, but I think some telescoping posts, the top portion is round (cylindrical) so can rotate freely when unclamped, whereas I think some others may be a D-section, with limited rotation even when unclamped. In the latter case, it would partially rotate like you said, indicating not totally clamped like it should be. Once that is figured out, you can "center" the steering by loosening the clamp bolt at the handlepost base, that clamps it around the fork steer tube, center steering with respect to fork, tighten clamp.

The lateral rocking could be:
- looseness at handlebar clamp, check that is tight.
- looseness at the telescoping clamp
- looseness at the base of the handlepost, which could be a loose hinge pin, but I think the later posts like on Mu's may have a different mechanism at the base, where the pin tightness is not a factor when post is locked up. Can't remember. In any case, the base will have an adjustment for closure tightness, you can see the adjustment nut when the post is "open" (folded).
- Loose headset adjustment; When the post is folded, and the clamp bolt loosened, there is a large 10mm(?) hex key bolt in center that adjusts headset, tighten that just snug, using the short end of the allen/hex-key wrench as handle, not the long end, (i.e., do not overtighten), then center steering and tighten clamp bolt.

(I don't have exact answers because my older Dahon Speed has a fixed, non-telescoping handlepost, and a simpler base clamp. In storage I have a Speed with the telescoping post, but it's not here to look at.)

Wilts1969

Thanks for your detailed response.

I've got in contact with Dahon to see if my serial number is in the recall batch, depending on their reply, I'll then progress to trying to source a suitable replacement if not covered. I've seen some non-branded stems & column on e-bay, so may have to consider that route. It's only a 5-6 times a year use as a casual cycle into the nearest town, so I didn't want to be throwing a kings ransom at the bike if I could help it. Now to find out which size telescopic column is required is required on this model.

Once again thanks for taking the time to reply, much appreciated.

Duragrouch

Stem recall details, easy to check:

https://www.cpsc.gov/Recalls/2009/da...to-fall-hazard

tds101 

Go with a LitePro handlepost... They're a solid, decently priced choice. I swear by them.

https://www.aliexpress.com/w/wholesa...38502c25pSr12N

I ordered multiple times from aliexpress with no real issues, EXCEPT for the abominably long waiting period for order to arrive from China. The LitePro stuff was top notch!

Ron Damon

FnHon handleposts are good too.

Duragrouch

(aliexpress above) Nice looking handleposts, I like that they have one-piece ones, a bit more rigid and I think better in durability in the long run versus telescoping posts. Also nice, come in different lengths, up to 40cm. My old Dahon fixed steel handlepost is 44cm, but I'm sure if I look hard enough, there are longer ones available. I wish they would publish the "angle" of the posts, either the inclination forward versus the steer tube, or forward offset at handlebar height from steering axis. It's still a question for me, if I change things, to go with less offset and no handlebar clamp, and install a suspension stem instead.

Ron Damon

You don't have to look hard. In fact, you don't have to look at all. Here's a 41cm long, banana shape Litepro job. It sells for under $40, and it doesn't have to be replaced every two years at a cost of €200 like the one on the Avian.

Duragrouch

Hey Ron (or anyone else), I was looking online at various handleposts and ran across this diagram, referencing a Dahon Radius V Comfort lower handlepost 09; Have you ever seen this and know how it works? It doesn't look like it's reversing the base 180 degrees, because in both positions it is tilted forward:


Darned if I can figure how they would do that with the folding base.

I know I might get the same effect with a double-clamp-stem setup, but I'm still interested in this. Thanks.

Ron Damon

Don't know, sorry.

Wilts1969

Thanks for all your help and suggestions, it's very much appreciated. After not hearing back from Dahon in a week, I've re-sent another email hoping that someone may actually reply.

Failing that, I'll get the tape measure out the the existing stem collar and make sure I get the correct replacement for the stock stem on the Dahon MU P8. Next stop Ali-xpress and the Litepro or Fn Hon:-)