Folding bikes

[Sky]

These are kind of cool:

YouTube - YikeBike - Urban Freedom

YouTube - YikeBike - pre launch party

[2dabeach]

We were satisfied with our Dahons until I was riding home from the post office recently and the aluminum seat tube that supports the seat fractured and split in two. Almost fell off the bike and scraped my upper leg on the remaining section of the seat post. I contacted Dahon and was told "While a broken seat post is uncommon, metal can fatigue over the years. We suggest you try our new Biologic Post Pump". I never had metal fatigue cause a failure on any bike I ever owned. That reply gives you a good idea on how Dahon manufactured their bikes and supports their customers.I would spend the extra bucks and buy a quality product.

[85MH325]

Originally Posted by 2dabeach

We were satisfied with our Dahons until I was riding home from the post office recently and the aluminum seat tube that supports the seat fractured and split in two.

Most manufacturers have a lifetime warranty on their frames. If your seat tube fractured, I'm surprised that Dahon won't replace the frame for you.

Like auto manufacturers, bike manufacturers have products tailored at different price points. To achieve that, there are areas where compromises are made. Less expensive bikes are typically not ridden as much. When a less expensive bike is pressed into service as a daily commuter, they fail at a much higher rate... WalMart $89 mountain bikes are a prime example. Usually it's the components that fail though, not the frame itself.

Damage (dings, dents, and so forth) can also weaken a structural component on a bike. That kind of damage can occur more easily on a folding bike simply because of how they are used, transported, and stored.

Not knowing which model Dahon bikes you had or how you store or use them, it's obviously impossible for any of us to determine exactly why yours failed, but it would be interesting to know which model Dahon bikes you had, how old they were, and how much use they saw before yours failed. BTW, seat post failures are fairly common from fatigue, especially on mountain bikes that are ridden hard. Seat tube failures are less common. If a seat tube fails, its usually at the seat post clamp on a frame that the seat post is moved regularly on. Usually folding bikes also have a rider weight limit... and obviously the closer one approaches that limit, the more likely stress failures are to occur in the bike components and frame.

On higher end mountain bikes, a good Thompson seat post (marketed as one of the strongest available) alone can run $150.

Roger

on edit: after re-reading your post and Dahon's suggestion of replacing your seat post with the Biologic Pump seat post, I presume that your frame is intact, and it's the seat post that needs replacing... I likely have the same seat post on my Trek F600s and F400. They're about the most stout seat post available on a mass-production folding bike. The seat post on the Giant Halfway is only about half as stout as the Dahon post.

[2dabeach]

Originally Posted by 85MH325

Most manufacturers have a lifetime warranty on their frames. If your seat tube fractured, I'm surprised that Dahon won't replace the frame for you........Roger

Roger The Dahon is the "Speed 21" model # LC014 and was purchased in Mar 2000 for $450.00 . We used it occasionally when on vacation with our sailboat and starting using it during the past four winters camping in Florida when we could no longer take our mountain bikes with us after purchasing our Airstream. According to the specs, the seat post is made from T6-6061 aluminum. The post broke off just below the place the tube narrows down to accept the seat. I am not Happy with Dahon, as I thought they would at least want to inspect the seat post to try to determine the reason for the failure.

[wahoonc]

I have seen a couple of seat post failures recently. Both happen to have been on older Dahon bikes. Aluminum has a different fatigue process than steel and quite often will fail without warning.

If I understand you correctly the bike is 10 years old? Dahon could care less about a bike of that age, for all they know you left it outside and used it for stunt riding.

I was in my local bike shop a few days ago and someone brought in a Schwinn from about 1970, the crank arm was broken off Those things are made out of cast steel! I have seen a few bent in my day, but never broken. We were looking at it and noticed that about half the cracked area was discolored, which means that was an old break that finally failed when a 200# person stood on it, versus the 100# kid the bike was originally purchased for.

Buy the biologic seat post and keep on riding. FWIW I recommend purchasing Dahon products from ThorUSA. He has a good reputation and stands behind the products he sells.

Aaron

[2airishuman]

Originally Posted by 2dabeach

Roger The Dahon is the "Speed 21" model # LC014 and was purchased in Mar 2000...

hi 'beach...

it's NO fun having a seat post fail while on the bike.

i have had this happen a couple of times, once with warning and the other time without any warning.

it is NO FUN to ride 15 miles home withOUT being able to sit...
____________

but this is a 10 year old seat post and aluminum does fatigue/fail often withOUt warning.

i'm not a fan of THAT specific d' frame (the folding connection can weaken/fail under stress)

but again it's 10 years old (i assume it's not been used a LOT but 10 years is 10 years)

and apparently failed where one would EXPECT failure (at the top/neck)...





small wheeled ADULT bikes typically have VERY LONG seat posts ((that one is 18-22 inches ? ))...

and they must tolerate a LOT of stress, MUCH more than a typical 10 inch post.

while it's not likely written anywhere obvious, these bikes had a rider limit of about 170-180 lbs...

IF the frame is crack free, straight, and the seat post TUBE opening OK, get another post as has been suggested.

but IF u are over 200 lbs, get another bike.
__________

and fyi MOST of the newest/strongest/lightest/most expensive/respected seat posts...

have a 1-2 year warranty for failure, while some have a limited lifetime warranty 4 manufacturing 'defects'...

many serious mountain bike riders CHANGE seat posts annually or every 2 years because of POTENTIAL failures...

i do have a couple of seat posts on ROAD BIKES that i expect to last 25-30 years...

but they are titanium and cost more than most COMPLETE bikes made 10 years ago.
__________

D' made a boat load of that model/frame style so OLD exact replacement posts can be found on da'bay...

but that's buying some1 else's ABOUT to fail post...
__________

again i think we understand the surprise, UNhappiness and upset,

but at 10 years one should be expecting hubs/spokes/rims/bottom bracket and a variety of parts to fail...

occasionally there are RECALLs for defective or potentially defective bike parts...

but i don't see 1 for that specific seat post...

cheers
2air'

[Gene]

The bike thread is back. After considering buying folding bikes last year, it seemed good ones were really expensive, and less expensive ones were cheap and couldn't take much abuse. So we did nothing. Then we went camping last summer with friends who have very, very expensive bikes. They brought an extra one for me to try out. Barb has a pretty good road bike. Our friends are people who have ridden cross country and are somewhat intense about bikes.

I tried one and found that despite all my exercising, I wasn't exercising bicycle muscles. I was a weakling. The only time I had been on a bike in the past 30 years was earlier last year when Barb and I rented a tandem—that was a strange experience. My atrophied muscles were not convincing me to buy a bike. I didn't feel comfortable on that bike either. The next day our female friend went out with Barb and friend hit a pothole in the dirt road, went over the handlebars and gashed her knee and elbow. Much gravel and dirt had to be removed, stitches applied, and all eventually healed. Male friend had fallen off his recumbent the day before and scraped his leg nicely. This did not make me want to buy a bike ever. These guys are experts and they are falling off their bikes!

A neighbor's husband died late last year and his mostly unridden mountain bike is available to buy. I think it's a Specialist. Barb is interested and thinks we could bring her road bike and the mountain bike on trips. I don't think the bike killed him but after our other friend's experiences, I'm not sure.

I have no idea how I could fit two bikes (without damaging them) and all the other crap that lives in the pickup bed. I was originally looking into folding bikes because they are easier to stow away.

The bike thing, like this thread, just won't go away. Maybe I can get a power chair.

Gene

[flakeyjake]

We love our folders, but we also service them regularly like the truck and the trailer so they continue to work properly. As to dying when riding, even the pros have met their demise when racing.

Bikes, like A/Ss, will never go away.

Hugh

[HiHoAgRV]

1, 2, 3, 4, breathe! Ok, really old thread is back alive...

Thru a weird series of events I now have a Classic Dahon Stainless folder. I gotta buy new tires (and get my running gear balanced?) but so far it's a pretty cool camping bike. Kinda heavy, around 30 lbs but it sure fits into the bed of the truck/shell better than our full sized ones.

Any suggestions for 16" tires? I can swipe a set of soild rubber ones off of the neighbors kids bike he got for christmas but I'm betting there are some better choices...

[wahoonc]

Originally Posted by HiHoAgRV

1, 2, 3, 4, breathe! Ok, really old thread is back alive...

Thru a weird series of events I now have a Classic Dahon Stainless folder. I gotta buy new tires (and get my running gear balanced?) but so far it's a pretty cool camping bike. Kinda heavy, around 30 lbs but it sure fits into the bed of the truck/shell better than our full sized ones.

Any suggestions for 16" tires? I can swipe a set of soild rubber ones off of the neighbors kids bike he got for christmas but I'm betting there are some better choices...

Steal the kid's tires... go ahead I dare ya!

I use Kenda Kwest on mine, one is still running the original OEM tires. Cheng Shin is another reasonable brand. Got pictures of your bikes? I have two of the old Dahon Classic III's, along with several other "folding" bikes; Raleigh Twenty's, Atala, Columbia, Rixie...

Have bunch of big bikes too but that is another story.

Aaron

[HiHoAgRV]

Here is how it arrived home. Some of the hardware is rusty, I plan on bead blasting and painting. The chain guard is MIA but other than that it rides pretty good.

[flakeyjake]

I would recommend Schwalbe Marathons (had these on my 16-in wheeled recumbent) or Greenspeed Scorchers. Also, take a wheel in to a bike shop that sells 16-in tyres and have them see how easy or difficult it is to mount/dismount the tyre casing from the rim. On my 20-in wheels, the Kwests were always hard to work with while the Schwalbes were easy.

[gandttimes]

Another vote for the Schwalbe Marathons. I had KWests on my Bike Friday folding tandem ( 20in) an after 2 blowouts, changed to the Schwalbe and the difference was quite noticeable.
George

[wahoonc]

I like Schwalbe tires too, but they can get pricey... Especially if you have a fleet of bikes like I do.

I do use them on my most ridden bikes.

Aaron

[Airtandem]

I have run the Schwalbe "Big Apple" and Marathon tires on my bent tandem. I like the Kevelar for reducing the chance of getting a flat. I changed brands after having 3 flats and only 2 repair kits and walking 5 miles home with my Kwests.
As a safety factor, I like the reflective sidewalls of the Schwalbes.