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Front Derailleur Clamp Overtightened
Just bought a used steel frame with slight indentation on seat tube
resulting from prior owner overtightening the front derailleur clamp. The tube has an indentation about .5-1.0 mm deep all around the tube in the shape of the clamp. Is there a problem with continuing to clamp a FD in the same spot? I am having some other work done on the frame. Should I have a sleeve brazed over the tube? Thanks, Wayne |
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Front Derailleur Clamp Overtightened
Wayne wrote:
Just bought a used steel frame with slight indentation on seat tube resulting from prior owner overtightening the front derailleur clamp. The tube has an indentation about .5-1.0 mm deep all around the tube in the shape of the clamp. Is there a problem with continuing to clamp a FD in the same spot? I am having some other work done on the frame. Should I have a sleeve brazed over the tube? What frame is it? On a 753 or an EL I might be concerned but on an SP or similar, surely not. It may also be paint deformation and not a dent. At any rate it won't harm you if it does crack [1] and the only suitable repair is a new seat tube. On most frames I'd ignore it, on delicate materials I'd inspect often and ride it anyway until or unless a crack appears. [1] may have to walk home but you won't land on your nose. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
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Front Derailleur Clamp Overtightened
quality duct tape from HD at $11 roll. |
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Front Derailleur Clamp Overtightened
On 03/10/2011 01:05 PM, Wayne wrote:
Just bought a used steel frame with slight indentation on seat tube resulting from prior owner overtightening the front derailleur clamp. The tube has an indentation about .5-1.0 mm deep all around the tube in the shape of the clamp. Is there a problem with continuing to clamp a FD in the same spot? I am having some other work done on the frame. Should I have a sleeve brazed over the tube? Thanks, Wayne is the seat tube straight or butted? if straight, I'd be tempted to try to work the dent out with a dowel, or a socket on a locking extension. However, I'm not a bike wrench, so I don't know if that's actually a good idea or not. nate -- replace "roosters" with "cox" to reply. http://members.cox.net/njnagel |
#5
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Front Derailleur Clamp Overtightened
Nate Nagel wrote:
On 03/10/2011 01:05 PM, Wayne wrote: Just bought a used steel frame with slight indentation on seat tube resulting from prior owner overtightening the front derailleur clamp. The tube has an indentation about .5-1.0 mm deep all around the tube in the shape of the clamp. Is there a problem with continuing to clamp a FD in the same spot? I am having some other work done on the frame. Should I have a sleeve brazed over the tube? Thanks, Wayne is the seat tube straight or butted? if straight, I'd be tempted to try to work the dent out with a dowel, or a socket on a locking extension. However, I'm not a bike wrench, so I don't know if that's actually a good idea or not. If indeed it is dented (paint deformation is common there), the butt of a butted tube is below the FD clamp area. If it's crimped from a derailleur clamp and is then formed back out smooth (mandrel and hammer or mandrel and rolled in steel blocks) before clamping the same part over the same spot I don't see where you necessarily come out ahead. If anything that may aggravate the situation. Depends. As I wrote earlier, it may well be simply paint deformation and we still don't know the material. With 1.6mm mild steel tube you can work most any machinations you like with impunity. On a tempered 0.3mm tube, not so much. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
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Front Derailleur Clamp Overtightened
On Mar 10, 6:46*pm, AMuzi wrote:
As I wrote earlier, it may well be simply paint deformation and we still don't know the material. With 1.6mm mild steel tube you can work most any machinations you like with impunity. On a tempered 0.3mm tube, not so much. -- Andrew Muzi * www.yellowjersey.org/ * Open every day since 1 April, 1971 The bike is an early 2000 Santana Arriva. Tube set is supposed to be Columbus 8/5/8. Can't be sure, but my ear tells me it is butted well below the clamp area. Removal of paint in the deformed area confirmed it was paint deformation. I never would have guessed that because the paint was not cracked or split and very hard. It took some effort to scratch through the paint but after removing the paint I discovered an unblemished seat tube., Thanks for the great information. There is no substitute for experience. I appreciate the contributions of shop owners like you that share thier knowledge. I have in the past and will continue to support your shop with phone orders and encourage others to do so. Wayne Sulak |
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Front Derailleur Clamp Overtightened
On Mar 10, 6:05*pm, Wayne wrote:
Just bought a used steel frame with slight indentation on seat tube resulting from prior owner overtightening the front derailleur clamp. The tube has an indentation about .5-1.0 mm deep all around the tube in the shape of the clamp. Is there a problem with continuing to clamp a FD in the same spot? *I am having some other work done on the frame. *Should I have a sleeve brazed over the tube? Thanks, Wayne I used to be a bit cack-handed with my early racing bikes and I'm sure I'd have done it if was possible. I'd guess a braze-on boss has been removed and the band on derailleur was fitted whith the paint still soft. I've had exactly this work done, quickly, but have never moved the clamp. I'd expect an indentation to be there. Whatever it is, rub back the paint and use a filler before rubbing back again and finishing with a colour coat. You need to be able to move your derailleur height depending upon the outer chainring. |
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Front Derailleur Clamp Overtightened
On Mar 10, 7:05*pm, Wayne wrote:
On Mar 10, 6:46*pm, AMuzi wrote: As I wrote earlier, it may well be simply paint deformation and we still don't know the material. With 1.6mm mild steel tube you can work most any machinations you like with impunity. On a tempered 0.3mm tube, not so much. -- Andrew Muzi * www.yellowjersey.org/ * Open every day since 1 April, 1971 The bike is an early 2000 Santana Arriva. *Tube set is supposed to be Columbus 8/5/8. *Can't be sure, but my ear tells me it is butted well below the clamp area. Removal of *paint in the deformed area confirmed it was paint deformation. *I never would have guessed that because the paint was not cracked or split and very hard. *It took some effort to scratch through the paint but after removing the paint I discovered an unblemished seat tube., Thanks for the great information. *There is no substitute for experience. *I appreciate the contributions of shop owners like you that share thier knowledge. *I have in the past and will continue to support your shop with phone orders and encourage others to do so. Wayne Sulak buy a series of big ball bearings, to press the dent out from the inside. 8/5/8 doesnt apply to seat tubes. butt is only the bottom, wall thickness,is straight at the top for seat post fitting. |
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