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peugeot cracked frame
Hello, I have an older Alummium frame Peugeot.There is a small crack
near the top of the seat tube.It happened when a taller rider raised the seat to high.How much of a problem is this? Can I just lower the seat back down and ride or are there safety issues? What about repair if necessary? thanks dave |
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#2
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peugeot cracked frame
On 28 Feb 2006 14:40:11 -0800, "davec" wrote:
Hello, I have an older Aluminium frame Peugeot.There is a small crack near the top of the seat tube. It happened when a taller rider raised the seat too high. How much of a problem is this? Large, if the crack is below the top tube. Smaller and possibly easy to deal with if it's above the top tube. The top of the seat tube is one of the most heavily stressed parts of the frame; no crack there should be ignored. Can I just lower the seat back down and ride or are there safety issues? If the crack is above the top tube, is there enough of the seat tube present that you could simply shorten it to remove the damaged area, and then relocate the seatpost clamp? Depending on the crack's location and orientation, it might even be possible to simply stop-drill the crack and ride on, though I doubt that this will be the case. If the crack is below the top tube, or if it's above the top tube but not in a location where removing the damaged end is an option, things are less hopeful. If the seatpost is long enough, a failure would probably not be of the type in which the rider is suddenly and unexpectedly dumped from the bike at speed, but the potential for both additional damage to the frame (rendering it completely unrepairable) and hazard to the rider is more than I would be comfortable with. Given that you are aware that the failure was causes by misuse, there's no warranty issue involved. Your choices essentially come down to repair or replacement. What about repair if necessary? This is something that would have to be addressed by a frame shop. It's possible that locating a replacement frame and transferring your components would be a more economical solution that trying to weld the crack, particularly if the frame is bonded instead of welded. If the frame is bonded, there are probably more repair options than if it's welded. -- Typoes are a feature, not a bug. Some gardening required to reply via email. Words processed in a facility that contains nuts. |
#3
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peugeot cracked frame
Werehatrack writes:
On 28 Feb 2006 14:40:11 -0800, "davec" wrote: Hello, I have an older Aluminium frame Peugeot.There is a small crack near the top of the seat tube. It happened when a taller rider raised the seat too high. How much of a problem is this? If the crack is above the top tube, is there enough of the seat tube present that you could simply shorten it to remove the damaged area, and then relocate the seatpost clamp? Depending on the crack's location and orientation, it might even be possible to simply stop-drill the crack and ride on, though I doubt that this will be the case. Sorry, but if you are talking about a crack in the top tube being a problem then I think this statement is false. The top tube is the least-stressed tube in a bicycle today. That's why it was always a 1" tube on vintage bikes, whereas seat tube and downtube were 1 1/8. The top tube is under compression. This is not a severe load. Dents in the top tube - bad ones - often produce no structural consequences. The downtube is the most heavily stressed tube, since your whole body weight is trying to rip the downtube out from the bottom bracket and from the lower head lug. The seat tube takes a lot of flexion from pedaling and so cracks in the seat tube (especially near the bottom bracket area) can easily grow. If the crack is in the seat lug, if any, then I think you are in trouble because the crack will likely grow larger. Depending on the location you should probably either attempt to sand or file smooth the insides of the crack to remove stress risers and prevent it from growing larger, or just ditch the frameset. If you keep the frame it want be good to get a well-fitting 400mm post in an attempt to spread the torque from your body over a wider area of the seat tube. - Don Gillies San Diego, CA |
#4
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peugeot cracked frame
Werehatrack writes:
On 28 Feb 2006 14:40:11 -0800, "davec" wrote: Hello, I have an older Aluminium frame Peugeot. There is a small crack near the top of the seat tube. It happened when a taller rider raised the seat too high. How much of a problem is this? If the crack is above the top tube, is there enough of the seat tube present that you could simply shorten it to remove the damaged area, and then relocate the seatpost clamp? Depending on the crack's location and orientation, it might even be possible to simply stop-drill the crack and ride on, though I doubt that this will be the case. Sorry, but if you are talking about a crack in the top tube being a problem then I think this statement is false. The top tube is the least-stressed tube in a bicycle today. That's why it was always a 1" tube on vintage bikes, whereas seat tube and downtube were 1 1/8, and on many high-tech bikes the downtube is 2x larger than any other tube. The top tube is under compression. This is not a severe load. Dents in the top tube - bad ones - often produce no structural consequences. The downtube is the most heavily stressed tube, since your whole body weight is trying to rip the downtube out from the bottom bracket and from the lower head tube/lug. The seat tube takes a lot of flexion from pedaling in the bb area and so cracks in the seat tube (especially near the bottom bracket area) can easily grow. If the crack is in the seat lug, above the top tube, then it may not grow larger. Depending on the location you should probably either attempt to sand or file smooth the insides of the crack to remove stress risers and prevent it from growing larger, or just ditch the frameset. If you keep the frame I would at least get a well-fitting 400mm post in an attempt to spread the torque from your body over a wider area of the seat tube. - Don Gillies San Diego, CA |
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peugeot cracked frame
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#6
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peugeot cracked frame
davec wrote:
Hello, I have an older Alummium frame Peugeot.There is a small crack near the top of the seat tube.It happened when a taller rider raised the seat to high.How much of a problem is this? Can I just lower the seat back down and ride or are there safety issues? What about repair if necessary? thanks dave cracking is a serious issue - it can lead to sudden catastrophic failure, and personal injury. if you can post a pic here, it would be handy. if not, discontinue use as the prudent action. repair of aluminum frames is uneconomic as they require heat treatment. |
#7
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peugeot cracked frame
davec wrote:
Hello, I have an older Alummium frame Peugeot.There is a small crack near the top of the seat tube.It happened when a taller rider raised the seat to high.How much of a problem is this? Can I just lower the seat back down and ride or are there safety issues? What about repair if necessary? If the crack is above the top tube, there's probably no danger from catastrophic failure. If the crack is small enough, drill 2 small holes, one at each end of the crack. That's about the only practical repair. It might help to use the longest seatpost you can find. |
#8
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peugeot cracked frame
davec wrote:
Hello, I have an older Alummium frame Peugeot.There is a small crack near the top of the seat tube.It happened when a taller rider raised the seat to high.How much of a problem is this? Can I just lower the seat back down and ride or are there safety issues? What about repair if necessary? thanks dave Is the crack vertical or horizontal? EJ in NJ |
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