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Discussion Starter · #1 ·
I was wondering if anyone had any experience removing a bound shock mount bolt form a '16-'18 Stumpjumper Carbon frame.

As I was removing the shock bolt to do an air can service I heard a couple pops coming from the bolt, however the bolt was turning freely. Once the bolt had backed out from the threaded insert I was not able to remove it from the frame as I have done before. Furthermore I can not get it to re-engage in the threads by turning forwards. When I rotate the bolt I can see the spacers between the frame and shock eyelet (pictured below) rotating with the bolt but can hold those in place with my fingers. Am also sure that the bolt has not sheared as I can see both ends turning.

After saturating the exposed threaded region with PB blaster overnight I have tried popping it out using a hammer and undersized bolt from the backside and wiggling the bolt head with vice grips to no avail.

During previous maintenance the bolt shaft was always coated with a light coat of Park grease and the threads with blue loctite and torque'd to spec. Given that the bolt is rotating I am pretty sure that it is not corroded in place. Below are some photos showing where the bolt is located at the moment.

Has anyone had any experiences like this or have any suggestions before resigning myself to dropping it off at a shop?
 

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Pad something heavy (several pounds) with a few layers of rag and hold it against the frame on the bolt head side. Then tap the other end of the bolt with a punch (or similar). Backing the frame with a weight increases the effectiveness of the tapping the bolt by reducing the amount the frame moves in response.
 

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I had this happen on my Ibis a few months ago. It didn’t make any sense to me. Threads weren’t engaged but bolt wouldn’t come out. And it wouldn’t go back in either. I was like “WTF? What’s keeping this bolt in?”

Using a punch, I started with some light taps, trying both directions. Ended up taking some way harder whacks and the PB Blaster to get it to come loose. I never did figure out what was keeping it in.

If you have another bolt of the same pitch, maybe try threading it in to push the stuck bolt out. Just an idea. I’d be really careful not to flex the frame tab too much.

Or try solvents or lubes of increasing levels of aggressiveness. The PB Blaster was a good thought. Maybe alcohol or a mild degreaser next.

Good luck.
 

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Discussion Starter · #5 ·
Thanks for the suggestions. Went back with a board wrapped in a towel and was able to position it between my leg and the frame so that it was supporting both the top and bottom tubes. Gave it several quick blows with a punch without any movement of the bolt. Wasn’t sure I wanted to hit it much harder. Going to let it soak in PB blaster longer and will try again.

Definitely a ‘wtf’ situation. Am wondering if the shock eyelet is somehow twisted relative to the bolt and thus pinching it.
 

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Thanks for the suggestions. Went back with a board wrapped in a towel and was able to position it between my leg and the frame so that it was supporting both the top and bottom tubes...
That's a big improvement, but the inertial of something heavy with minimal padding increases the sharpness of the taps. I suggest something like a two pound hammer head or similar held against the frame with a couple of layers of rags.

The weight and incompressibility makes a big difference. I know this from extracting press-in BBs and other bearings that were installed with retaining compound.
 

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Discussion Starter · #8 ·
Quick update for everyone who chimed in. After a few more attempts of hammering out the bolt with various heavy objects bracing the frame I decided that the best course of action was to drop it off at the lbs.

In the end the bolt had to be drilled out. The mechanic saved the bolt which was straight as an arrow and lacked any corrosion. What he did find was that there was a good deal of play between the upper shock mount and the mounting hardware which was traced back to the wrong size mounting hardware for the frame. I suspect that at some point the shock mount moved in a way that caused the bushing to be misaligned with the bolt and ended up pinching the threads when I tried to remove it.

New bolt installed along with new mounting hardware. There was still some play between the shock mount and mounting hardware but apparently much less than before. Crossing my fingers that it doesn’t happen again.

Thanks for all the input.
 
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