I love my dahon, but it's been nothing but problems
 

i have a 2007 Dahon Speed P8 20" wheel folder. it's a great little bike and it was the bike that got me back into cycling after a long hiatus, but it's been one problem after another with the bike.

first, here's a pic of the bike with the mighty chicago skyline as backdrop:

http://img261.imageshack.us/img261/585/bikeskyline2.jpg


the first problem was quite minor, but the emergency pump in the seat post broke when it fell out of its housing going over a bump and it got caught in a road crack that bent the shaft, rendering the pump useless. not a huge deal, but annoying none-the-less.

then last spring, while giving my bike a tune-up, i noticed frame cracks starting to form around the seat tube. the speed P8 is a cro-mo model and i was very surprised to see frame cracks developing in a steel frame bike that was only 2 years old and had never been in a wreck or mistreated. i took the bike back to the dealer where i purchased the bike and much to their and dahon's credit, they honored the lifetime frame warranty and switched out the cracked frame with a brand new identical frame free of any charge.



pic of the frame cracks:

http://img706.imageshack.us/img706/1904/framecrack1.jpg



after the frame crack issue was resolved, i ended up riding my dahon a lot less frequently. it became my reserve commuter bike, only used on days when inclement weather threatened so i could duck into the nearest CTA station and fold it up and ride the train if needed (i really don't enjoy riding in the rain like some hardcore commuters do).

then this spring, while once again giving the bike a tune-up, i noticed a dangerous looking crack that went all the way through the rim of the rear kinetix pro comp wheel. i took it back into the same shop and the they said the crack definitely made the wheel unsafe to ride, but that the warranty on that part had now expired. a replacement wheel is gonna cost me ~100 bucks.



pic of the rim crack:

http://img256.imageshack.us/img256/8341/crackr.jpg



so now the bike sits hobbled, waiting for me to decide when to pull the trigger on getting a new wheel. i've since purchased a 3rd bike in the meantime, so i still have two other bikes i can ride, but i do miss the flexibility of having the folder for bad weather days (CTA doesn't allow normal bikes on trains during rush hour). however, with the problems i've already had i fear what lies next down the road if i do get the new wheel fix and start riding it again. the bike is only 3 years old and has already had some fairly serious issues.

sometimes there are lemons.
my aluminum dahon vitesse from 2007 or 8 has been going on quite well.

Weird man. Nonetheless, sorry to read about the negative experience. The frame thing is quite surprising, IMO. The wheel thing -- I can't see it in the photo -- less surprising. How many miles on that rear wheel?

My Curve D3's been fine-- and I'm at the outer limits of height and weight for it.

The Espresso that I picked up used has done over a year of hard urban commuting. Only problem there was when the original already past their prime Kendas dumped me over in black ice.

Otherwise, plus one to what invisiblehand wrote.

How do you like those Shimano 530's? (the pedals)

I'm starting to feel the same way about the two Dahons I've been riding. My Curve D3 has had a frame alignment problem right out of the box, the two rear dropouts are not parallel to each other; and now I've discovered a front fork alignment problem with my Vitesse, I just removed front wheel for the first time and discovered overtight cones, underlubed bearings and a bent axle, and the wheel would not remount straight once I rebuilt it.

I'm not sure about the rim crack because I cannot see it in that photo. Could you put it in Paint, circle it, and repost it? To be honest all I can see is the rim wear grove but I assume that you know that is supposed to be there. My Mu P8 is coming up on a year old and while I have not had it out much this year (long story) it is doing quite well so far. I did change out the brake pads over the weekend when I found that they were worn and had lots of aluminum flakes embedded in them, especially on the rear. That can scuff your rims up and if you have the same then maybe that is all you have, as I say I can't see the crack. On the one hand Thor can sell you a wheel for $87, but with tax and shipping its gonna be ~$100. It does come with a new cassette apparently.

Ken

Looks like the rim cracked in the wear indicator groove. The worn patch on the rim is presumably where the brake rubs the resultant bulging section. I reckon that's a manufacturing fault and should be honoured by guarantee.

The frame crack - that is not uncommon and I have long maintained that is a design fault - long lever (seatpost), fulcrum (seat stay), short lever (shim). recipe for enormous stress on the weakest point, the --- * drum roll * --- stress relief hole!

You can see nicely in the pic how the seat stay lines up perfectly with the crack site. Nicely done, Dahon.

that sucks about the seat crack. i imagine you followed the guidelines with the seat post minimum insertion requirements?

There is another possibility. Get a new rim and have someone build you a new wheel, or do it yourself. It could probably be done for well under $100. You can also try to beg a new one off Dahon but the warranty limits their responsibility to pay for items that break no matter what the cause. So if they aren't in a generous mood you won't get any results that way. Doesn't hurt to ask.

Ken

what just happened
I write a 5 page letter opinion and click reply to thread and I get a blank ... what the heck ?

thor

You would thing that forces from the lever, seat tube, are reacted by the seat stays at the top and top tube at the bottom. Thats where the stiff spots are. This assumes that the seat post has enough insertion to engage the top tube.

I wonder if when the holes are drilled or punched if there are not some fine cracks from the process that later become larger as their stressed.

i'd estimate somewhere in the ballpark of 5,000 - 6,000 miles.




love 'em. with my dahon out of commission, i've switched them over to my new motobecane road bike (which i use as a commuter). i LOVE having the option to be clipped in or not. i LOVE not needing to worry about what footwear i have on if i just want to grab a bike and go run a quick errand. to me there's no reason in the world not to have a dual sided pedal because i'm not a gram-counting racer and all of my bikes are used in a variety of recreation & utility roles.




that's precisely where the crack is, and the worn patch on the rim is from the section that bulged out. the pic may not show it clearly, but the crack is actually all the way through the rim. when i held the rim up to a window, i could see tiny rays of daylight coming through. not safe at all. it might be a manufacturing defect, but with the bike being 3 years old, the dealer said that it would be impossible to know if it's from defect or rider abuse/misuse, accident, or other unknown force, so no warranty.




Always. i'm only 5'-9" so i never came anywhere close to minimum insertion line on the seat post.




i already asked (see above) and they weren't in a generous mood :(

probably better as I had some views about this which might not have been along some of the lines above....
,
thor

So I reassessed my Vitesse wheel last night. The fork seems OK but the axle is bent enough to affect performance - the bearings bind and if the wheel isn't loaded into the fork with the axle at just the right angle, the wheel is completely out of alignment in the fork.

So I went to my local Dahon dealer and tried to buy a new axle - this is a bike that's still under warranty, but I figured it would be faster and easier just to replace the axle myself. The dealer called the company rep and it turns out that Dahon doesn't stock small parts and the only way I can get a new axle is by replacing the whole freakin' wheel. Plus they don't have the wheels in black. The local dealer said that in their experience Dahon just canabalizes other new bikes for these parts instead of maintaining inventory of parts. How lame is that?

I ended up with a new aftermarket 150mm axle that I'm going to have to cut down to 110mm to fit.

I'll also rant a bit here about the rim-eating brake pads that came stock on this bike. Tektro's with the words 'for alloy' molded into their backside. I've had experience with these 'for alloy' or 'for aluminum' brake pads before; they have 1-2mm chunks of aluminum cast into the brake pads that reduce the life of rims substantially. Once I got wise I replaced them but some damage had already been done.

As much as I like my Vitesse, I think I'm done buying from Dahon until they can get their act together a bit more.

after seeing that crack on the seat tube, I checked my vitesse and I've got the cracks too.
not as bad as in the OP picture, but I can definitely see and feel it.
I'll have to take it into an LBS and see what they can do with the warranty.

I thought the stress relief cut was on the back instead of the front. Maybe this is why the frame is more susceptible to damage?

the newer Dahon frames have a gusset welded on in front of the seatpost that is supposed to reduce flex in this area and prevent these cracks from forming.

I lost a reissue Raleigh chopper frame when a crack formed in this location. Raleigh's warranty explicitly said that alloy frames were not covered.

thanks, but that's still a whole hub, which is more than I need, and it's not in black, which is the color I need.

:)

Yeah, well... Occasionally you get what you pay for. Or a little less. ;) I had a low-end Dahon for awhile, and had a few more mechanical issues than with similarly-priced standard bikes. However, I haven't seen any solid statistics on Dahon's (or anyone else's) repair rates.

Hopefully the replacement frame will be the new design. As to the wheel, while I concur it's possible that it is a manufacturing flaw, and that 20" wheels are generally stronger than larger ones, after that many miles it's a little harder to identify the true cause.

I'd say if you aren't feeling it, sell it. Just make sure you either fix the wheel first or fully inform the buyer that the rear wheel must be replaced. If you really miss having a folding bike, consider picking up a higher-end folder.

Welding causes the steel tubes to temper around the joint areas. that part of the bike already receives a lot of stress and cracks.
if the bikes were brazed i would think the possibility of premature cracking in your situation would be significantly reduced.

"Lemons" are supposed to be screened out by something called "Quality Control" at the factory-certainly not at the dealer or at the final purchase at the customer's end. I have finally adjusted to the new reality of "gambling" to get a working product of any type-not just bikes. I purchase something and bring it home. I make sure to use it as much as I can for at least a week or under any time frame specified by the warranty or purchase agreement. If it works that is wonderful as there are no headaches for me and the product should not give me any major trouble for it's intended lifespan. If the product is defective, I make sure I bought it originally at a retailer that has a good return policy and return it very quickly. Plus I usually use a credit card with additional protections for this built right in.

Thank for reinforcing something I was merely suspicious of for quite awhile now can actually place my finger on. I still think that Dahon makes wonderful bikes. I still have the 2 I bought new for quite a while now. But they are certainly not perfect. I treat them like I would do a car that is over about 3 years old. With not 100% complete trust in them (much like a cheating spouse).

Steely Dan /AEO Do your bikes have an alloy shim in the seat tube?

yes.

I had a look at my 2009 Vit. today, alloy shim, no sign of cracks, but the slot and cut-out are (appear to be) the same. My 2006 D7 had a plastic shim, hence the question.

yes. both my old frame that cracked and the new replacement frame had/have an alloy seat tube shim. in fact, in the detail picture of the frame crack in the first post of this thread, you can see the alloy shim through the seat tube slot.

OK, I goddit now, on mine the slot is at the rear of the bike, not the front, and there's a fillet welded in from the top tube to the front of the seatpost. (My 2006 bike had a plastic shim. )

mine is at the rear, but the frame is made from aluminum.

Yup, and you have a crack. Any news yet?

waiting for warranty.

the whole reason I bought aluminum vitesse over steel mariner was because I had to ride it in winter.
lots of brime here.

does yours have the extra gusset on the front side?