petko8680

Hi guys,
was just given a used, but in excellent condition dahon helios bike. Reason for giving it away is that the stem at the very bottom locking mechanism( the one circled in the picture) is loose, so it is turning left or right with just applying small effort, which makes it dangerous to safe as as on as I try to steer, only stem goes in the desired direction, but wheel is keep going straight. I think it is the bracket that has an allen bolt on it( the one you use to fold the stem), but problem is that I can tighten it all the way. There is still about a 1mm gap between the two parts of the bracket, so they don't join completely. I tried to tighten as much as possible, but it doesn't allow me to tighten it all the way. But when I tighten it as much as possible, you need to apply much more pressure in order to turn the stem. Which makes me think that that bracket is the problem. The allen bolt looks a bit short( not sure if that how is meant to be), because when tightened it doesn't go all the way to the end of the thread. So i am wondering if replacing it with a longer one will allow me to tighten the bracket all the way so that both ends can join. Cheers

ThorUSA

I would give you qa link to my site, where it explains how to adjust the handlepost, BUT some moderator would surely bann me again ....
which is silly as others in the industry have their homepages listed in the signature and freely make advertising for their brand... but I digress..

somebody els will find the link under technical ... dahon recall ... and surely post it for you
thanks thor

HGR3inOK

petko8680 - There is some good technical information on Dahons and Terns available at Technical.

-HANK RYAN-
Norman, Oklahoma USA

petko8680

Hi,
thanks. I went to that website, but couldn't find any info that might help me. also went to halfords today and explained them my problem, so the guy there told me it might be the length of the allen bolt that causes that issue. What do you think guys?

ThorUSA

ok .. when u open the handlepost ... u see a big allen bolt silver shiny ..I think its a size 8 ...
You loosen the outside allen bolt ... and than tighten the big shiny one to the point where you have no wobble or free play in the steerer colum.... than you tightne the outside smaller allen bolt ...
voila
done

petko8680

By "a big shiny allen bolt", you mean the one that looks like a circle with a hexagonal hole in the middle(the circled one in the picture below. that's the only picture with similar item I managed to find, as bike is not with me now)?

ThorUSA

yes
see the plate on the left .. don't tighten the bolts there, the plate needs to move

petko8680

OK. Do you mean the plate in the upper right corner, with the two holes in it? The one that should basically lock the handlebar stem, right? I will not touch it at all- will only tighten the big circle shaped allen bolt and the small one on the outside.

petko8680

Hi,
I've done what i've been told and tightened the allen bolt inside the steering column. It actually locks the fork when tightened all the way down. But still got the issue with the loose stem. What else do you think it night be?

P.s. what should be the length of the small allen bolt located at the bottom of the stem? Mine is 1" including the head of the bolt. Cheers

thugpipe

Are you sure that the play in the system is in the head set/stem attachment? have you put one hand on the front wheel and one on the handlebar and pushed in opposing directions while look at the stem? Photos and/or a video would be very helpful

petko8680

Hi,
can't post a video now, but let me try to explain it one more time, as I think I might have not done it properly in my first post. So, basically when all the handle bar and handle bar stem latches are locked, and I hold the front wheel tight between my legs and start turning the handbar to the left or right, it moves almost without any effort from bottom part all way up. Basically the whole stem turns left or right, but the wheel( and fork of course) isn't. So, if i try to ride, as soon as I try to steer, my bike keeps going straight, but my handle bar turns to desired direction. I am start thinking that it all comes from the allen key bolt at bottom of stem as it is just 2.5cm long and I think it needs to be about 3 or 3.5cm.
Will be more than happy to hear your advice.

ThorUSA

several right answers above to fix it.
Now ...would be the time to look for adealer ...any bike dealer ..