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So I have carbon jeffsy in, in very used condition!
The main pivot and the seat tube pivot both undo but push the linkage apart as opposed to sliding out. The bolt for both is stuck in the center tube or in the bearing inner race.
Soaking over night in penetrating spray but as the path of least resistance isn't between the bolt and sleeve there is little chance it will work.
As the seattube bolt is only accessible from the nds I think the only option to free the linkage is to drill the alu bolt out from the bearing race/inner sleeve!
I think this will be the only option for the main pivot only!
New drill bits, increasing in size, lots of patience, cutting fluid. Should be fine!
Have I missed any other solutions before this? I think not
screw extractor on a slide hammer? Put it in the freezer overnight?
sorry , i cant really picture it
Penetrating fluid works by capillary action so should still find its way between the bolt and whatever it's seized with. It may take several applications to have any effect though, can you seal one side with blu-tack and flood it for a couple of days?
If you do end up drilling it out make sure you can get replacement parts before doing so.
Heat can really help, pouring on a kettle of hot water did the trick for me with a stuck bolt a while back
Replacement parts all ready checked
Slide hammer would do nothing as the thread is still engaged when the carbon starts to look like splaying
Carbon and heat aren't friends
(*im not picturing this too well)
Before drilling I’d try soaking in release agent, can you lie bike on side , try to seal the bottom bit (cling film, , rubber band, anything , silicone etc etc) and using cling film, blutack , silicone, putty etc etc anything make a funnel /reservoir at top that you can fill with the release agent so it can soak down overnight and get everywhere and see if it will work in.
this is probably very daft /stupid see note at top), but if you could take the nds side nut off, and using a socket end that would fit over the top of the bolt but hold against the washer (ie to allow the bolt head to push out but hold everything else in place), then brace that against an immovable object and try to punch out from the other end , Sort of try to push the bolt out from the nut side but prevent any sideways movement of anything but the bolt ,
Or put it in a vice so you could push against the nds to push the bolt out.
apologies if the above is cobblers /doesnt make sense/just won’t work
First bit is in the op
Diagram above
Can't push it out as the thread is still engaged when it starts to push the carbon apart so can't go any further with undoing the thread until it moves in the central tube
No nuts to remove, threads are captive in the linkages
Apologies, didn’t quite understand situation.
Surely some hot water can't hurt, carbon gets baked in pretty hot ovens
Bicycle Frames/Posts: Intense heat (like a fire) can destroy carbon fiber, but even excessive heat from boiling water can stress the resin and bonds, risking catastrophic failure in critical parts.
Get some timber and cobble together a clamp around the carbon to stop it spreading.
Those arrows look like that are pointing at bearings not bolts. Anyhow, my question is, as they are all on the same side of the bike, they're not left handed threads are they?
Dude the there are not the issue
Video shows what happens when the bolt on the seattube pivot is undone
Pic 2 shows the drive side captive thread head being covered but carbon so no access
Pic 3 shows the main pivot from the drive side
These 2 show the pivot moving to the right when the thread is undone
Get some timber and cobble together a clamp around the carbon to stop it spreading.
This is what I’d do. Or use a few large quick-grip clamps
Spread the load as much as possible, good plan
Drilling won't work as the threads will either still be engaged or will the up damaged
Surface isn't flat enough to clamp
Need to think again
What’s at each end of the bolt ? Presumably on the bolt side a washer etc, is there something solid on the other end.
could you nose a socket (or spacer or old bearing etc etc) into each end (on the bolt side one with a hole big enough to allow the Allen key thru and the bolt to extract into it, but where it sits against the washer holding that in place ) so that you have two flat bits that are sticking out of the frame and then clamp those bits with bits of wood/metal with two bits of threaded rod etc with a hole to let the Allen key thru on the bolt side
?????? Could you clamp using a wide tidedown or luggage strap.
Lots of zip ties used as a clamp?
What’s at each end of the bolt ? Presumably on the bolt side a washer etc, is there something solid on the other end.
could you nose a socket (or spacer or old bearing etc etc) into each end (on the bolt side one with a hole big enough to allow the Allen key thru and the bolt to extract into it, but where it sits against the washer holding that in place ) so that you have two flat bits that are sticking out of the frame and then clamp those bits with bits of wood/metal with two bits of threaded rod etc with a hole to let the Allen key thru on the bolt side
?????? Could you clamp using a wide tidedown or luggage strap.
That's kind of what I was thinking but with box section. I can't visualize your idea 💡
The strap idea might work
So. Not sure if you've sussed this yet but basically the pivot bolt is stuck to the inner race of the bearing.
As you turn the bolt it's staying where it is then pushing the frame out instead.
Slowly undo the bolt whilst hitting the frame with a rubber mallet and it should break the corrosion bond between the pivot bolt and the bearing.
Done this loads on rear hubs when the rear axle corrodes to the hub bearings.
Careful though....
That was deduced 24 hours ago dude. I think it's actually stuck to the central tube
Not hitting a carbon frame!!
Tapping with a rubber hammer should be fine. The shock could help release whatever is stuck.
I think it's sensible to tap out at this point
Surface isn't flat enough to clampNeed to get creative with some offcuts of wood/plate and strips of inner tube to level everything out. Have seen it done with a carbon wishbone before.
on the bolt side one with a hole big enough to allow the Allen key thru and the bolt to extract into itLike that. Just need a piece of wood or plate with a 16-18mm hole in it and another straight piece, two clamps to bridge/clamp the whole thing and enough rubber to take out the profiles etc. Should then be able to peel the bolt out of the corroded tube with the bolt. Or you'll pull the insides of one of the bearings out. Importantly, you'll be able to get all the bits out
for the clamp imagine a square , left and right sides are wood or box, top and bottom are threaded rods, through the wood/box sides, with washers and bolts on each end , so by tightening the bolts on both rods you compress the clamp.
sort of like below.
I ** guesss** so may be wrong the bolt head will tighten onto a plate or washer etc to protect the bearing beyond, so if you can get a socket , where the nut end part goes over the bolt head and pushes against that washer/plate you should be able to put the Allen key thru the socket and still undo the bolt.
if on the other end you can do something similar with a socket/spacervetc etc you should be able to clamp across the ends of the sockets (As they should be sticking out of the side of the frame)
If you then Drill a hole in the clamp side so you can get an Allen thru through the clamp side , then thru the socket, then into the bolt you should be able to undo the bolt into the socket and the clamp should stop things spreading (** but it very much depends if you can mount the sockets onto something appropriately solid and strong enoug to take the force of the clamp so I’d check that out.
a wide strap might be a lot less effort.
freeze spray from a plumbers supply place? Spray internally to contract the inner sleeve.