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Seized & snapped bottle cage bolt – options?

inquisitorinquisitor Posts: 9
edited 13 February in Workshop
I tried to remove a bottle cage from my titanium Tripster ATR frame the other day… and the bolt snapped at the head.

So I drilled a hole into the bolt remains and then used a reverse-threaded screw extractor to try and back it out. This is the result:



What are my options now? I have a chunk of steel in an aluminium bolt in a titanium frame.

I've tried using a punch to rotate the remains of the screw extractor so that I can back it out, but have had no success so far – it seems to be jammed.

Posts

  • MattFalleMattFalle Posts: 4,200
    drill it out using a Ti drill bit from b&q, re- tap thread using tap and die set from b&q, put new bolt in but grease it of copperslip it this time.
  • How would I get a straight and centred hole?

    The broken surface of the extractor is very angled, so I think the drill bit will just wonder off to the side if I try to drill into it. Normally I'd use a centre punch to start the hole, but even the punch just slides over the surface 😕
  • MattFalleMattFalle Posts: 4,200
    you could [email protected] file it flat
  • MattFalleMattFalle Posts: 4,200
    not enough extractor to grab hold of with pliers? am thinking not...
  • arlowoodarlowood Posts: 2,519
    Main strategy should be to drill the whole lot out. The screw extractor will be hardened steel so you need a drill bit that will cope. Carbide steel bits could do the job but they are very brittle and need to be used in a very rigid set-up like a tower drill or lathe. You could try them in a hand drill but I would suggest they are not the best option.
    You can get multimedia drill bits such as the Bosch Blue Granite which are carbide tipped. These should do the job

    https://www.amazon.co.uk/Bosch-HCBG600T-6-Piece-BlueGranite-Carbide/dp/B0000TZYZ2

    Not cheap as you may have to buy a set to get the size you need.

    One final option is to just try a basic masonry bit of the required size. They won't last long but they're cheap enough that you can buy several if you need them.

    Just be aware that the broken screw extractor will be brittle and could send shards flying as you drill so wear gloves and face/eye protection.

    Once you've managed to drill out the extractor/screw you need to remove the damaged rivnut and replace it. This video shows one approach to removing the damaged rivnut using a Dremel, that seems pretty neat. In the video he's demonstrating on a carbon frame. With your titanium frame you have lots of leeway

  • mully79mully79 Posts: 311
    If its a cheap extractor sometimes If you hit it hard enough with your centre punch it will shatter or push through the hole.
    That almost always works with a tap but theyre slightly weaker.
  • cryoman1965cryoman1965 Posts: 174
    edited 13 February
    To insert a new rivnut here is an easy homemade effort. Most people don’t have one as a standard tool in the garage.

    N






  • sungodsungod Posts: 13,529
    you might be able to exploit differential thermal expansion to loosen things...

    al has the highest coefficient, i.e. compared to steel and ti it'll expand more as heated and shrink more as cooled

    heating the exposed end of the bolt/broken extractor will tend to loosen the extractor, the tip of a soldering iron or a fine gas torch might do it, then try to back out the extractor (i'm assuming the frame is bare metal, don't try this if it's clear-coated!)

    freezer spray on the bolt might help loosen it in the mounting, but the chances are it jammed due to galvanic corrosion (the al corrosion product takes up higher volume, in a confined space this jams things tight)

    you can use chemicals to attack the aluminium, but if you can get the extractor tip out, easier drill/grind/file it out until it's weak enough to break up and remove

    with al fixings in steel/ti it's advisable to use an anti-seize paste (which should be a zinc-loaded one for al) to protect it
    my bike - faster than god's and twice as shiny
  • arlowoodarlowood Posts: 2,519
    edited 13 February
    arlowood said:



    Once you've managed to drill out the extractor/screw you need to remove the damaged rivnut and replace it. This video shows one approach to removing the damaged rivnut using a Dremel, that seems pretty neat. In the video he's demonstrating on a carbon frame. With your titanium frame you have lots of leeway

    Just had another look at the picks you provided. It looks like the bottle cage mount is a threaded boss welded into the titanium frame so my suggestion with the Dremel is best avoided as that was targeted at a standard rivnut type frame mount. Drilling and re-tapping in a slightly over-sized thread may be the only option then
  • photonic69photonic69 Posts: 1,135
    Had a similar disaster a few years back when a bleed nipple on the wife’s Fiesta sheared off. Drilled it and used an Ezy-out extractor but that broke off like the OP’s problem. Had to remove whole caliper and use a pillar drill and a very small bit to drill out the Ezy-out. It was a pig of a job even with the pillar drill. I’d take it to an Engineering shop rather than a LBS to get them to remove the remains. Then use your LBS to pretty up the damage.
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