Yet Another Cycling Forum

General Category => Freewheeling => Folders => Topic started by: drossall on 15 March, 2018, 11:25:00 pm

Title: Broken Dahon
Post by: drossall on 15 March, 2018, 11:25:00 pm
I wrote off my Dahon this evening. I hit a fairly modest pot-hole. The frame broke just behind the main joint. Looking at the metal, I can see that a problem had been developing in the weld (the metal is white), but it looks as though the actual main tube went pretty-much in one go.

I was dumped in the road of course. Nothing serious - scratches and clothing damage. However, it does shake your confidence in the design, especially as I come down the Pentonville Road every day. Glad it didn't happen at a higher speed there.

Obviously any single-beam design isn't as strong as a proper diamond frame. Any thoughts though on folder strength for a rider who is heavier, but not beyond the published design strengths of these things? Are Bromptons actually stronger than Dahons/Terns?
Title: Re: Broken Dahon
Post by: StuAff on 16 March, 2018, 12:16:12 am
Eeek. Glad you're OK. As a scrawny git I can't really help on the frame strength thing...
Title: Re: Broken Dahon
Post by: handcyclist on 16 March, 2018, 07:36:12 am
Eeeew, scary. Glad you're ok.

If it helps, I never thought my Dahon was very well made. They are definitely constructed down to price, and the are known to have quality control issues. I spent a long time facing the main joint on the one I had to make true so it tightened properly. In the end I lost faith in it and bought a secondhand Brompton, much happier with that.

I'm guessing you're not the first owner?
Title: Re: Broken Dahon
Post by: drossall on 16 March, 2018, 07:45:18 am
Correct. I believe it to be a 2006 model. I bought it from our very good LBS. They said it had sat on canal boat as an "In case we want to go somewhere" bike, very little used. Since September 2014, I've used it daily, commuting into London.
Title: Re: Broken Dahon
Post by: handcyclist on 16 March, 2018, 07:52:20 am
Mmm, wonder if the 'white' you refer to was corrosion ..... anyway, a Brompton get my vote. I think there is one in the FS section.

<edit> I see you've seen that!

Title: Re: Broken Dahon
Post by: Torslanda on 16 March, 2018, 07:52:55 am
I'm no Brompton apologist but I would point out that a steel frame is unlikely to fail in that way. Although it's pretty certain to be noisy before it does...
Title: Re: Broken Dahon
Post by: 1nterceptor on 16 March, 2018, 06:54:43 pm
Pretty happy with my 2013 Brompton S6L-X. Used it for my 16.5 mile one way commute for years;
in all kinds of weather:
https://www.youtube.com/watch?v=MLeZhBw3cjI&list=UUHyRS8bRu6zPoymgKaIoDLA&index=43
Have done some lite dirt riding a few times:
https://www.youtube.com/watch?v=pNuuT-nRer4&index=42&list=UUHyRS8bRu6zPoymgKaIoDLA
Been tossed about on over a dozen trips/flights. Pretty common to see my box upside down:
https://www.youtube.com/watch?v=LVLPtnQKwzQ&index=4&list=UUHyRS8bRu6zPoymgKaIoDLA
Title: Re: Broken Dahon
Post by: drossall on 16 March, 2018, 09:59:47 pm
Yes, I'm certainly thinking carefully about materials and construction for a replacement!

For the ghoulish, who like to see the corpse, here it is:

(https://www.dropbox.com/s/6ua0i0hga876chi/Dahon-break-main.jpg?raw=1)

(https://www.dropbox.com/s/a94x4b6uk2wtjr2/Dahon-break-front.jpg?raw=1)

(https://www.dropbox.com/s/tthqs20w82m8lnn/Dahon-break-back.jpg?raw=1)
Title: Re: Broken Dahon
Post by: StuAff on 16 March, 2018, 10:01:33 pm
Yes, I'm certainly thinking carefully about materials and construction for a replacement!

For the ghoulish, who like to see the corpse, here it is:

(https://www.dropbox.com/s/6ua0i0hga876chi/Dahon-break-main.jpg?raw=1)

(https://www.dropbox.com/s/a94x4b6uk2wtjr2/Dahon-break-front.jpg?raw=1)

(https://www.dropbox.com/s/tthqs20w82m8lnn/Dahon-break-back.jpg?raw=1)
:o :o :o
Title: Re: Broken Dahon
Post by: Kim on 16 March, 2018, 10:12:32 pm
Yup, that's b0rked.
Title: Re: Broken Dahon
Post by: drossall on 16 March, 2018, 10:36:07 pm
Thanks. I wasn't sure whether it might be fixable, but it's good to have one of the forum experts clear that up for me.
Title: Re: Broken Dahon
Post by: Kim on 16 March, 2018, 10:53:30 pm
Maybe with a fuckload of cable ties?
Title: Re: Broken Dahon
Post by: Torslanda on 16 March, 2018, 11:00:40 pm
You're missing a trick. There are two holes in the endplate of the borked bit. Bung some 3x2 in the frame, a couple of good length woodscrews through the holes and stick it on Gumtree. If you're bothered about frame integrity, get some gorilla glue. S'easy.

Robert's your auntie's live in . . .  :thumbsup:
Title: Re: Broken Dahon
Post by: drossall on 17 March, 2018, 08:05:26 am
See, now I'm in two minds. I was all ready to scrap it and buy a new bike, and the cunning repair ideas start coming in.

Torslanda, I could do you a discount on the bike if you'd like to buy it and do the repairs yourself?
Title: Re: Broken Dahon
Post by: PaulF on 17 March, 2018, 08:24:17 am

Maybe with a fuckload of cable ties?

Don’t be silly, something that big would need duck tape ;D

Or the standard Singletrackworld response: are you sure it’s not a sticker?
Title: Re: Broken Dahon
Post by: Jurek on 17 March, 2018, 08:36:42 am
Shame its not a steel frame.
You can repair those using magnets.
Title: Re: Broken Dahon
Post by: CAMRAMan on 17 March, 2018, 08:53:26 am
'Tis but a scratch...
Title: Re: Broken Dahon
Post by: Torslanda on 17 March, 2018, 08:57:24 am
See, now I'm in two minds. I was all ready to scrap it and buy a new bike, and the cunning repair ideas start coming in.

Torslanda, I could do you a discount on the bike if you'd like to buy it and do the repairs yourself?

I'd be interested in rebuilding it on a new frame . . .
Title: Re: Broken Dahon
Post by: ElyDave on 17 March, 2018, 09:37:02 am
Surely a bit of t-cut and it'll polish out?
Title: Re: Broken Dahon
Post by: Kim on 17 March, 2018, 01:02:49 pm
Shame its not a steel frame.
You can repair those using magnets.

If it was an electric bike, you could use electromagnets...
Title: Re: Broken Dahon
Post by: PaulF on 17 March, 2018, 01:05:51 pm
Shame its not a steel frame.
You can repair those using magnets.

If it was an electric bike, you could use electromagnets...

Surely that would mean it would fall apart when you stop at traffic lights?
Title: Re: Broken Dahon
Post by: zigzag on 17 March, 2018, 01:53:57 pm
send those photos to dahon with a short story and see what they say
Title: Re: Broken Dahon
Post by: Jurek on 17 March, 2018, 06:10:14 pm
Shame its not a steel frame.
You can repair those using magnets.

If it was an electric bike, you could use electromagnets...

Surely that would mean it would fall apart when you stop at traffic lights?
Always with the negative.
What is it with you? 
;)
Title: Re: Broken Dahon
Post by: Jurek on 17 March, 2018, 06:17:21 pm
send those photos to dahon with a short story and see what they say
Good call.
Title: Re: Broken Dahon
Post by: clarion on 18 March, 2018, 10:56:46 am
Shame its not a steel frame.
You can repair those using magnets.

If it was an electric bike, you could use electromagnets...

Surely that would mean it would fall apart when you stop at traffic lights?
Always with the negative.
What is it with you? 
;)
You trying to induce puns?
Title: Re: Broken Dahon
Post by: CAMRAMan on 18 March, 2018, 11:55:28 am
Guilty as charged
Title: Re: Broken Dahon
Post by: drossall on 18 March, 2018, 01:40:38 pm
Surely that would mean it would fall apart when you stop at traffic lights?
Well, given that on Thursday it fell apart when I didn't stop at traffic lights*, what's the difference?

*The pot-hole (actually a slightly-depressed grid cover, I now notice) was at a pedestrian crossing. The lights were green though.
Title: Re: Broken Dahon
Post by: drossall on 18 March, 2018, 01:42:56 pm
send those photos to dahon with a short story and see what they say
I dropped a note to Dahon on Friday. I'll let you know what they do say. I'm not sure I could expect a warranty replacement on a 12-year-old second-hand bike. However, in my view they ought to be concerned at their frames failing.
Title: Re: Broken Dahon
Post by: loadsabikes on 18 March, 2018, 03:02:58 pm
I do have a P6 with the titanium rear end. It also has a Son dynohub, an S bag and bike travel bag.
It is virtually unused, probably no more that 300 miles.
It has to go to finance a new forge.
Title: Re: Broken Dahon
Post by: drossall on 18 March, 2018, 03:28:15 pm
I'd be interested in rebuilding it on a new frame . . .
Torslanda

Sorry, I nearly missed this message amongst all the facetious ones. It does look as though I'll have a bunch of parts to get rid of - and I need the space for the replacement. I didn't really consider a rebuild, and you've given me pause for thought - but I think I've lost confidence in Dahon frames enough to think still that I want to move on. Also, the handlepost won't suit a modern frame, and I had to do some modest filing on the seatpost to make it move freely, so not sure whether that would work with a new frame.

Otherwise, though, the parts are as shown in that rather rough photo. You can see that I had the Dahon Ultimate rack and the Stash Box. The original rack is hanging in the shed too. MKS FD-7 pedals fitted - I've got one spare pedal (I broke one) plus the original standard rubber pair. Aber Hallo stem extension. Wheels are replacements (the original rims wore out) - front a Kinetix and rear just an ordinary upgrade with QR. Assuming I end up with a Brompton, I'd be happy to let that lot go for a donation to a third-world charity, if we can figure out how to get them to you.

Not to mention a couple of spare tyres, plus two winter tyres that I got on a heavy discount, ready for the next Beast from the East, on the day the bike broke ::-) , and a couple of gear controls that I never quite got round to trying. Those can go in Classifieds when I'm sorted.
Title: Re: Broken Dahon
Post by: Jurek on 19 March, 2018, 08:55:47 am
Shame its not a steel frame.
You can repair those using magnets.

If it was an electric bike, you could use electromagnets...

Surely that would mean it would fall apart when you stop at traffic lights?
Always with the negative.
What is it with you? 
;)
You trying to induce puns?

Not currently, no.