Terrible Dahon latch design
 

I just got back from dropping my new '06 Dahon Speed P8 off at the bike shop. I'm a little ticked off at Dahon at the moment. Now I am bikeless for the next week and I'm still not sure if they will even replace the part. What a crummy design they came up with for the handlebar/stem latch. The old method they used on the Boardwalk was much better. I don't know how they expect that small piece of plastic and those two little springs to "last a lifetime" as they say. I really wish I had looked closer before buying. They really need to redesign that.

If you "like" that cheap latch on a midrange bike, check out the safety on the main latch on a Birdy... a cheap bit of plastic on a very expensive bike.

@maunakea - the stem lever on a Birdy is fashioned from metal, but has a thin plasitc over-coat. If it was made out of plastic, I would never ride my bike!

That's the scary thing about the Dahon. If that piece of plastic ever cracks....I lose control and probably go flying. I can't believe they ever came up with that idea.

fear&trembing the Birdy latch I'm referring to is the safety on the main latch that releases the rear triangle to fold under the maintube, not the stem latch. All the Birdies I've seen in Japan (have yet to see one in the States) have a flimsy plastic safety latch.

[transition to hijack of a highjack] ... on the DT FS, the safety on the main latch is the spring loaded metal hinge pin... one of the many things I like about the DT frame.

@Maunakea - That thing! Bromptons don't even have that to keep the rear triangle in place! It is not really an issue - I actually think it is quite a clever little gismo (if tawdry looking) as it flexes in order for the screw to engage...

Yes... it is apparently safe ... no reports of Birdy crashes from the rear triangle unexpectedly going into stow position ... but it's a poor ornament on an otherwise well-engineered and fitted bike.

That was one of two failures on my Birdy, the the screw that that little plastic catch catches on (try saying that when you've had a few 'sherbets'!) pulled out of the frame, the other failure was the handle bars snapping off in my hands as I rode (luckily) uphill. 5 mins later I would have been doing 40 mph downhill! Yikes! Birdy sent a replacement to Avon Valley Cyclery in Bath and it was fixed free of charge.

Loose steering stem joint is v scary ! - I Have done it once on the Brommie and nearly lost it. I lost balance very quickly, and in the panic couldn't reach the clamp. At least that's human error as the joint is screwed tighter by hand so 100% adjustable.

I also have a love/hate relationship with the brommie tuck under rear.... love the way it instantly folds under to form a smaller standing package ... Hate when lifting bike up (eg over a step) , and the rear drops and dangles on the floor. It never happened but I also worried that if going down a really steep hill & I hit the front brake hard, all the weight would go forward and rear would tuck.
Merc seem to include a catch but its a 3rd part upgrade on the brommie.

Luckily I was just unfolding my bike when it went.

I would have thought if the problem of the Birdy and Brompton were so much of an issue, there would have been many cases seeing the volume that both manufacturers sell.

I believe R&M recommend replacing the stem and its latch after 3 years. The new model Birdies have a differently designed stem mechanism that is both stronger and safer.

I, too, am confused as to what actually broke. Maybe it's something new for '06? I can't think of 'two springs' anywhere on my P8. OP, was it A) the clamp at the top of the steering column, B) the hinge at the base of the steering column, or C) the folding hinge?

What plastic are we talkin about here? I cannot speak for all the other folders ,, just back to the original post about a Dahon .... Thats a pretty hefty chunk of steel in there. The only "plastic"is a piece of delrin which slides the quick release, instead of being metal to metal which would increase wear.
The new latch is a pretty neat piece of engineering allowing the stem to only unfold if the quick release is ALL the way open. Even without proper tension ( which is even adjustable ) the stem will hold 100 %.

All I can think off being plastic is the outside "hook" which is the second preventer of a loose quick release. That one might break if you run it into a wall, like many other items which will break, if the speed is big enough..... ( not Dahon specific and not even folder specific , if you crash hard than forks wheels headsets and what else not needs to be replaced . But even than I would bet that the latch will be still workin.

Thor

jackcoke can you drop by the LBS and take some pix before they fix it. there's probably time ... you're waiting on a part.

I am really curious as to what this plastic piece is also. Both my Boardwalk and Jetstream XP have a plastic little arm/hook that keeps the handlepost latch "secure". The Boardwalk has the older type latch and I have broken the plastic thing on there twice now. On the Jetstream it has never broken.

If that is the plastic thing you are referring to then I would not let my bike sit in a bike shop for a week waiting on that part. Use some velcro or something, be creative. If the latch is correctly tightened then the piece holding the latch up really does not need to be that strong, it is just a safety.

Plastic latch?
 

Totally agree W/ Thor's post. As a very satisfied Speed P-8 owner(2006) I too am very interested in which plastic thing failed. Please give us a better discription.

I don't have the bike here so I can't take a picture. I'm not sure what the correct terms are but I will try to describe the situation. Where the handlebar assembly meets the frame there is a latch mechanism. When you move the latch handle it pushes on a plastic piece that then moves a spring loaded metal piece to secure the handlebar assembly. With my bike the metal part with the two springs inside was not moving correctly, somehow was caught up on something but neither the bike shop owner or myself could determine where or why. Because it was jammed the plastic part was either having too much force put on it or not enough to hold it in place and it would pop off when folding. Once it got wedged to the side and became gouged up by hitting something it wasn't meant to strike. The whole thing is a mess. Hopefully they will replace the whole assembly. You can give plastic a fancy name but it is still plastic. It didn't take that much force to gouge this piece up, it is rather soft. That may be a good thing because you wouldn't want it to crack. If you own one of these bikes I think it would be a good idea to inspect this part once in awhile because if it fails there is no redundancy built into it.

The only things that look like plastic to me are the stopper hooks to secure some latches (depending on the bike model) as described in the manual.

see

http://www.dahon.com/support/manuals...pactmanual.pdf


Maybe there's a pic where jackcoke can see the plastic part he's talking about.

I found this on epinions.com. It sounds like I am not the only person that has had trouble with the handlepost latch mechanism. This came off a review of a Helios, it must have the same setup.

"I am riding this bike for a year now and the overall experience is great. I rode through Chicago winter and summer, rain and shine and the bike is still in great shape. Tires, brakes, shifts, handling is still perfect 10.
The only problem that this bike has is the steering column. The latch broke and needed to be replaced. It seems like a quite fragile solution and I would not recommend to try one of those Chicago type potholes."

What was Dahon thinking when they designed that damn thing....????

somebody is miffed .... I still can not find anything to substitute the claims.... there is a delrin slider in there which looks to the untrained eye to be plastic. Well its the same stuff I paid bucko dollars for to exchange the bushings in my car suspension. the same stuff which is used in high dollar applications where oterwise the wear and tear would destroy components.

I mean every dealer ( not just Dahon dealers) can order such parts from Dahon.

To google around and find other folks with seemingly the same problem .... well.... why not calling Dahon and get the problem fixed instead ???

thor

Day 10.....bike is still not fixed, Dahon has not replaced needed part.

@jackcoke

somehow I don't get it. Me and different others have asked you to define which plastic part broke.

Even some links have been posted to help you show the part you mean - for ex. http://www.dahon.com/technology/component/radius.htm
http://www.dahon.com/support/manuals...pactmanual.pdf

etc.

We still don't know what the damn thing is that broke/failed on your bike.

So either you're able to show/tell WHICH PART OR MECHANISM HAS FAILED or just stop complaining. It really doesn't make any sense like this.

Just my .02 cents

I just looked at my Jetstream.. having read some of the posts I think I know the piece.. enclosed is a photo.. I'd surmise the white platic piece pushing on the aluminum sliding latching plate is the piece that is buggered.. if the latch were improperly set up and a fair amount of force was applied to the latch handle in an effort to get the latch to close, then something has to give.... from the scenario, I would guess not only the plastic piece is ruined, but the aluminum sliding piece (with the two screws) would also be marked up as well as the handlepost it engages.... if I'm correct, I would assume that a new handlepost would be needed as this is a new bike and the bits should all appear new.. I don't think this is a bad design as I've never seen (nor have I heard) of any wear from that plastic bit and I fold an unfold my bike a ton...

Bruce

Adjustment?
 

Just wondering if the factory adjustment at the stem was altered or mis-adjusted. Seems to me that is the only way that part can be messed up.