Is my Fissure dangerous??
05-06-17, 10:26 AM
#26
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05-06-17, 10:30 AM
#27
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I read this after my long post. Your approach is good, but as an engineer I would humbly suggest that a machinist might be of more help/
You don't want to "lay" a collar with high-temperature forming: you want to machine one and shrink fit it. This is because to form something, you'd first have to machine the forming dies anyway. Male AND female. Machining the collar directly cuts the machining in half, and eliminates the forming step.
You could use aluminum, but you'd want the collar at least as thick as the original flange. I think steel would be less bulky and about the same weight (maybe less).
Many approaches shown in the Australian link you posted involved welding. You can weld your frame, but you'd then have to post-weld heat treat the whole frame which would require a new paint job. And that Bianchi pale green is sweet.
Whatever you do, if that crack has propagated to the head tube, get someone who knows what they're doing drill a hole to eliminate the stress concentrator (that is, the end of of the crack).
Good luck!
You don't want to "lay" a collar with high-temperature forming: you want to machine one and shrink fit it. This is because to form something, you'd first have to machine the forming dies anyway. Male AND female. Machining the collar directly cuts the machining in half, and eliminates the forming step.
You could use aluminum, but you'd want the collar at least as thick as the original flange. I think steel would be less bulky and about the same weight (maybe less).
Many approaches shown in the Australian link you posted involved welding. You can weld your frame, but you'd then have to post-weld heat treat the whole frame which would require a new paint job. And that Bianchi pale green is sweet.
Whatever you do, if that crack has propagated to the head tube, get someone who knows what they're doing drill a hole to eliminate the stress concentrator (that is, the end of of the crack).
Good luck!
05-07-17, 05:52 PM
#28
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Bikes: A steel framed 26" off road tourer from a manufacturer who thinks they are cool. Giant Anthem. Trek 720 Multiroad pub bike. 10 kids bikes all under 20". Assorted waifs and unfinished projects.
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If going steel, stainless would be the go no need to paint, but use a retaining compound to try and isolate the SS from the aluminium. A slightly thicker aluminium collar might cause less electrolysis.
Ream and face the headtube afterwards. Looking at where the crack is, it could be caused by the interference between the headset and tube being too small, it stretched the head tube causing a stress crack.
Ream and face the headtube afterwards. Looking at where the crack is, it could be caused by the interference between the headset and tube being too small, it stretched the head tube causing a stress crack.
05-07-17, 06:11 PM
#29
Its all about the cruise
I would take it back to where it was purchased and go from there. Its a very nice bike. to cob job the thing wouldnt be just imo...
05-08-17, 10:16 AM
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If going steel, stainless would be the go no need to paint, but use a retaining compound to try and isolate the SS from the aluminium. A slightly thicker aluminium collar might cause less electrolysis.
Ream and face the headtube afterwards. Looking at where the crack is, it could be caused by the interference between the headset and tube being too small, it stretched the head tube causing a stress crack.
Ream and face the headtube afterwards. Looking at where the crack is, it could be caused by the interference between the headset and tube being too small, it stretched the head tube causing a stress crack.
05-15-17, 03:39 AM
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