09-22-2013, 08:26 AM
Hi all,
I'm new here, but thought I would share my recent experience trying to repair a crack in my Merlin Taiga frame. The crack originated in the weld between the BB and the seat tube during a cycle tour in southern Chile. Two attempts at welding were unsuccessful and it was suggested by several shops that I junk the frame. Having $800+ invested in S&S couplers plus many thousands of miles of love and companionship, I couldn't do it, so I set out to find a repair on my own. My dad is a machinist and we contemplated a mechanical fix - some sort of brace or clamp, but it all seemed too complicated and time consuming. In the end, I went with carbon fiber/resin for ease of application and access to supplies and have just finished the very time consuming process of wrapping and epoxying, sanding and repeating many times. I found some websites of people building bamboo bikes and loosely followed their patterns for wrapping lugs, using 24K carbon fiber tow (basically CF twine, unbraided), wrapping up the down and seat tubes and the chainstays while crisscrossing under and over the bottom bracket. Several layers of resin with snippets of the CF thread followed, with heavy sanding in between each layer. A finish layer of straight resin finished. Below are pix of the final result. Jury is out on how long it'll last, but there's 5 layers of carbon fiber wrapped in various patterns and 7 layers of resin and it is incredibly hard and stiff. The objective was to halt the advance of the crack and stabilize the BB. Let me know your thoughts or if you have any questions.
[attachment=4473]
[attachment=4474]
I'm new here, but thought I would share my recent experience trying to repair a crack in my Merlin Taiga frame. The crack originated in the weld between the BB and the seat tube during a cycle tour in southern Chile. Two attempts at welding were unsuccessful and it was suggested by several shops that I junk the frame. Having $800+ invested in S&S couplers plus many thousands of miles of love and companionship, I couldn't do it, so I set out to find a repair on my own. My dad is a machinist and we contemplated a mechanical fix - some sort of brace or clamp, but it all seemed too complicated and time consuming. In the end, I went with carbon fiber/resin for ease of application and access to supplies and have just finished the very time consuming process of wrapping and epoxying, sanding and repeating many times. I found some websites of people building bamboo bikes and loosely followed their patterns for wrapping lugs, using 24K carbon fiber tow (basically CF twine, unbraided), wrapping up the down and seat tubes and the chainstays while crisscrossing under and over the bottom bracket. Several layers of resin with snippets of the CF thread followed, with heavy sanding in between each layer. A finish layer of straight resin finished. Below are pix of the final result. Jury is out on how long it'll last, but there's 5 layers of carbon fiber wrapped in various patterns and 7 layers of resin and it is incredibly hard and stiff. The objective was to halt the advance of the crack and stabilize the BB. Let me know your thoughts or if you have any questions.
[attachment=4473]
[attachment=4474]
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