So on the ride with the kids I dropped off a high curb with my road bike. Heard a snap and saw a bolt on floor. Aftwr much seeking I managed to find the bolt and upon much investigation with the kids realised its the bolt for the bottle cage that goes into frame.
Then thought of Colin (I remember once he or someone of that caliber said using lightweight bolts was daft... to my innocence, it was the bolt that came with the frame albeit alloy).
So now I have a sheared bolt inside frame and just 3 weeks before a chairty ride for which I need the bottle cages. whats the best tool/brand to fetch this out... my dremel won't work as the sheared bolt is flush with the frame!...
Easiest way is to use slow speed drill to screw it further in. It will then drop into seat/down tube. Either just leave it inside the frame (you'll not notice it at all)or remove BB and shake it out.
mfezela wrote: ↑Sat Dec 07, 2019 2:46 pm
Easiest way is to use slow speed drill to screw it further in. It will then drop into seat/down tube. Either just leave it inside the frame (you'll not notice it at all)or remove BB and shake it out.
Shouldn't be a problem detting it out of frame as theres a hole in bottom covered in a plastic grommet (for di2 ready stuff)... slow speed drill you say. Wouldnt that rip into the bolt itself as it apears to be made of cheese...
It being soft just makes drilling easier rejoice that it is not stainless steel.
Two options
1 drill grips blt and scres it in
2. drill goes all the way through bolt,
if the later then do as below.
slow speed and a tiny drill bit once through - if it has not dropped then size up and repeat -
Eventually it will just peel the thread apart /you can bend it out into the hole where the bolt was - go slowly when you get to the bigger drill bits and use a slow speed throughout
Usually cleats for me and takes say 5-10 mins per cleat
As aluminum is soft this will just make it much easier for you
You do get bolt extractor drill bits but i not worth bothering for this bolt
Have you tried to unscrew it yet? As the heads sheared off there shouldn't be any tension on the bolt so provided it's not corroded in you might be able to turn it with say a scribe which has a sharp point and you can get it to rotate, easier to do than described.
I'd try to just use the head to wind out the shank first. It wouldn't need to come out much until you could grip it with some pliers or mole grips.
Next try would be a tiny dab of super glue if you think you could pop the head back on without glue going on the frame.
I don't suggest trying to drill counterclockwise but to turn bolt further into and thus through the hole. Unless you've used high strength Loctite, or similar, the bolt should turn as the bit bites but before it starts cutting. A slightly dull bit can help here.
A low speed high torque drill is easier to control. It's unlikely you have space within the frame but a hand brace is ideal.
One caveat: the surface of the sheared bolt needs to be as flat and perpendicular to the thread as possible. This limits possibility of drill bit slipping and distributes torque evenly on the threads. Also (OK, two caveats) place drill bit centrally on bolt shaft.
Thanks eveyone. That's indeed feeling as though I've contacted Nasa themselves. Will try with what Sean said first as I have a Wiha flat head which I ended up bending once so I guess it was ddstined for this event...
Next up one of the drilling methods (either drill it in or drill a hole in it for a torx to hammer in and wind out)...
Driving instructor (for the buses) taught us whilst midtraining: "if you don't ask, you don't get"... so another
Managed to unscrew it out by just holding the broken head over it and unwinding. Thanks all for reminding me how simple it could be (or else I might have resorted to complex methods)...
Nice one.
Funny really, having been lead a merry dance by many such similar mishaps over the years, I now immediately reach for industrial methods to deal with these occurrences forgetting that sometimes, the simple method works.....
htrider wrote: ↑Fri Dec 13, 2019 11:46 pm
Nice one.
Funny really, having been lead a merry dance by many such similar mishaps over the years, I now immediately reach for industrial methods to deal with these occurrences forgetting that sometimes, the simple method works.....
Amazing isn't it. Plus I guess it shows that all them anti seize cimpunds are worth it when winding stuff in for the first time...
Anyway I realised why it happened (I think). Over the years when I've been jumping curbs or going over some gravel bits, cos the Passport bottle cage extender was at its limits, each bump must've been putting a little stress on the (alloy) bolt as the cage tried to push itself further down south. Anyway, I've put paid to the problem to protect from next time. Added some new (alloy*) used bolts but used around 3nm of pressure ** and also left a few mm for the extender to not keep pressuring the head if it moves.
*like you do.
** coynter productive I know and logic suggests using correct torque means the passport adaptor wouldn't slip in first place... but at least this way (hopefully) I'm not putting the rivets at risk..
