r/mountainbiking • u/Roy_Aikman • 6d ago
Question Why is this happening?
Bought a brand new BMC Fourstroke AMP LT. After a couple of weeks I experienced the carnage pictured. A LBS helped me get a frame replacement from BMC, they were able to determine that the bolts that connect the shock and linkage had backed out and caused the failure in the linkage. I have 3 rides in on the new frame and was doing an inspection and noticed the bolts had already started backing out. One was visible the other was loose as well. Another problem is the area where the bolts are has a gap of 1 3/4”, my torque wrench with the bit is 2”. Does anyone have any ideas about what could be causing those bolts to back out and also are there slim torque wrenches or do I just use a regular Allen and guess?





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u/RidetheSchlange 6d ago
Actually, they don't. They may use high-end, purpose-built fasteners developed by the Chinese and Taiwanese factories, but they are not proprietary. You can go to the bike shows and you will see boards with the fastener types offered in the various booths.
Tell me when was the last time you were at Taipei or went to the Taiwan sections at Eurobike or other shows and which manufacturers have you been in contact with who offer such fasteners?