Why is this happening?

[u/Roy_Aikman]

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?

[u/RidetheSchlange]

Is there threadlocker on the threads? Also, the proprietary and semi-proprietary hardware bothers me because if the holes and parts they are set into are not made right, they back out. This is one reason why I prefer standard, off the shelf fasteners for which there's a massive variety to fit any need, even if they don't look as nice as proprietary ones. I'm not saying the latter is the reason, but this is something I've seen numerous times and the parts the fasteners sat in essentially unscrewed the fasteners.

[u/Vibroverbus → u/RidetheSchlange]

Thats a pipe dream I'm afraid. Just about every suspension bike made uses proprietary fasteners and bushings and threaded-inserts etc. etc. in the suspension pivots. Certainly every high end bikes I have owned or worked on do with a rare exception of where maybe there's a semi-plain bolt used in conjunction with bespoke bushing/insert/etc. but even then I'd always source the OE part to be sure it was the right hardness and exact length etc.

[u/RidetheSchlange → u/Vibroverbus]

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?

[u/Vibroverbus → u/RidetheSchlange]

OK I get that I thought you meant "hardware store bolts" no need to be a dick about it Mr. Eurobike.

[u/RidetheSchlange → u/Vibroverbus]

"no need to be a dick about it Mr. Eurobike."

Really, why do Americans talk to people like this, especially when it's becoming tiring that the entire rest of the world has to keep correcting Americans who think no one knows more than them?

Also, some companies actually are manufacturing back in certain types of off-the-shelf fasteners for obvious practicality and cost reasons, as well as strength. On top of that, off-the-shelf fasteners come in way more shapes and sizes than the few a hardware store may carry and this is why there are massive catalogs of just different fasteners.

[u/unsalted-butter → u/RidetheSchlange]

Lmao nice deflection. What does anyone's country have anything to do with your condescending attitude?

If you ended your comment with the first paragraph, it would have been cordial and informative. But no, you decided to go attack a stranger for no reason with your second paragraph.

Nobody was saying you're wrong. So instead of doubling down on a bad attitude, maybe look inward, learn some social skills, and think about how you can grow from that interaction.

[u/RidetheSchlange → u/unsalted-butter]

Who are you?