Snapped allen bolt in carbon steerer expander bung

[rliu]

Hi I was putting in a new carbon bung, the Deda Elementi (

View: https://www.amazon.co.uk/Deda-Elementi-Expander-Bung-23-5x70mm/dp/B079DKRN32/ref=pd_sbs_200_4/260-8071634-7930534?_encoding=UTF8&pd_rd_i=B079DKRN32&pd_rd_r=133c02a4-90a1-4c3f-929b-72a7f6b9c4d6&pd_rd_w=8kw0X&pd_rd_wg=lP1x7&pf_rd_p=96cae456-8d7a-4bc1-91c7-9b20b4dfd7c9&pf_rd_r=G2KJSC80J30GRVEB573B&psc=1&refRID=G2KJSC80J30GRVEB573B
)
The bolt snapped as there was play in the headset even when the top cap bolt felt tight, so I probably over-tightened. As it's a relatively delicate area, just wanted to know if anyone else has got a snapped bolt out with a screw extractor or gone to a bike shop to get one out?

 

[davidphilips]

Only a guess but if you did not loosen the stem bolts and have tried to adjust out free play by keeping tightening the bung perhaps if you just loosened the stem bolts the bung would just lift out, if not then its only a mater of a very light push or tap to the middle of the bung to loosen it and it should lift out (with the stem bolts loosened)?

 

[rliu]

I wish that were the case but I had tightened with stem bolts loose. The Deda bung was not fully removing play even when I was tightening with stem bolts loose, but now with the top bit snapped it's not loose enough to just knock out of the steerer.

 

[derrick]

If the head had sheared of the bolt. Just knock whats left of bolt through.

 

[rliu]

If the head had sheared of the bolt. Just knock whats left of bolt through.

I considered doing that but the rest of the bolt is still quite tight. This bung is also the longer length one (70mm) and most of the bolt is still there even with the head sheared off. I don't want to go too hard on knocking it out as to damage the steerer, as what's left of the bolt is still holding the expander rings in place and there isn't a lot of play in the headset even without the top cap.

 

[derrick]

I considered doing that but the rest of the bolt is still quite tight. This bung is also the longer length one (70mm) and most of the bolt is still there even with the head sheared off. I don't want to go too hard on knocking it out as to damage the steerer, as what's left of the bolt is still holding the expander rings in place and there isn't a lot of play in the headset even without the top cap.

A short sharp tap should do it.

 

[Yellow Saddle]

Tap it and drink a beer. Stop phaffing about.

Then go and find out why overtightening it didn't remove clearance.

 

[derrick]

I considered doing that but the rest of the bolt is still quite tight. This bung is also the longer length one (70mm) and most of the bolt is still there even with the head sheared off. I don't want to go too hard on knocking it out as to damage the steerer, as what's left of the bolt is still holding the expander rings in place and there isn't a lot of play in the headset even without the top cap.

The thread will only be screwed in to the bottom part of the expander.

 

[rliu]

Tried having a look at possibility of tapping out but it's also still attached to another screw at the top, as per below photo.
Have tried to reattach the sheared off head with JB weld and try and unscrew out in a day or two. Otherwise I think taking it to a shop to drill out is the best way forward.

 

[rliu]

Have two bikes so been holding off sorting this one out for a few weeks, started drilling into it with a normal drill bit for a pilot hole then trying to reverse drill it with a screw extractor but not getting any purchase in it at all. Any ideas why that may be?