I've got a Dahon Mu P8 which I bought in spring 2007. The frame broke 5 months later just above the soldering for the tube mount (where the seatpost slots in). This kind of crack would probably happen if the seatpost was above its max setting but I am nowhere near the max!
I got my bike back 12 weeks later (!). Now, it's been about 3 months of cycling on the new frame and I am concerned the frame is going to break again. I've got the exact same creaking noise happening arount the same spot on the frame when riding it. It is not showing any visible signs yet but the noise gets more frequent and at this rate it won't last another month!
I've seen at least one other person with that problem on a different (older) model (http://groups.google.co.uk/group/uk.rec.cycling/ browse_thread/thread/fa7a665c84cbfae0/58498b9a466bf33f? hl=en&lnk=st&q=dahon+broken+frame#58498b9a466bf33f)
Has anybody experienced anything similar on a Mu P8 or other Dahon models?
Has anybody experienced anything similar on a Mu P8 or other Dahon models?
This is no help to you, but I have a jetstream xp 30 months old and given it a hammering on long rough rides on roads and trails . I weigh 15 stones. I have been expecting something to break among the delicate lightweight parts but so far nothing has.I put long bar ends on the carbon bar and although something creaks when Honk up hills it seems to be surviving.I destroyed one of the lightweight QR levers very quickly but am more careful with the others. Even the wheels are still quite true. TerryJ
I've got a Dahon Mu P8 which I bought in spring 2007. The frame broke 5 months later just above the soldering for the tube mount (where the seatpost slots in). This kind of crack would probably happen if the seatpost was above its max setting but I am nowhere near the max!
I got my bike back 12 weeks later (!). Now, it's been about 3 months of cycling on the new frame and I am concerned the frame is going to break again. I've got the exact same creaking noise happening arount the same spot on the frame when riding it. It is not showing any visible signs yet but the noise gets more frequent and at this rate it won't last another month!
Sounds like they might have had a bad batch of frames - the tube right next to the weld is weakened by welding heat, but that should be corrected by heat-treatment after the frame is built. It's also possible that the seatpost is undersize (or the seat tube was reamed oversize) which would place higher loads on that area - if there's significant wobble when the clamp is undone you could try shimming the seatpost (Coke can is the classic shim material :-).
I've got a Dahon Mu P8 which I bought in spring 2007. The frame broke 5 months later just above the soldering for the tube mount (where the seatpost slots in). This kind of crack would probably happen if the seatpost was above its max setting but I am nowhere near the max!
Quoted message said:
I got my bike back 12 weeks later (!). Now, it's been about 3 months of cycling on the new frame and I am concerned the frame is going to break again. I've got the exact same creaking noise happening arount the same spot on the frame when riding it. It is not showing any visible signs yet but the noise gets more frequent and at this rate it won't last another month!
Sounds like they might have had a bad batch of frames - the tube right next to the weld is weakened by welding heat, but that should be corrected by heat-treatment after the frame is built. It's also possible that the seatpost is undersize (or the seat tube was reamed oversize) which would place higher loads on that area - if there's significant wobble when the clamp is undone you could try shimming the seatpost (Coke can is the classic shim material :-).
That sounds interesting about the sizes. I suppose you are talking about the different diameters in that area. Well, I think this bike has a peculiar design because it has a very large tube (the seatpost tube contains a pump). Additionally around that area there is another internal cylinder (probably 10cm long, 1mm wide) which acts like your shimming I suppose. It seems most of the support is on this internal cylinder but not too sure. The clamp is secured quite tight so that may have an impact!? I'll look into this additional shimming.... Thanks for your help.
