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I'm off on a bike-packing trip next week on my carbon Salsa Warbird. Bought a new pump, yesterday tried to take a bottle cage off to swap the pump mount and discovered one of the bottle bosses is just spinning in the frame.
I've tried dribbling some superglue into the joint between frame and boss, hoping it would wick into the gap - which on the face of it worked, but the very audible "crack" I got when I put a full waterbottle in the cage suggests it hasn't held. The top face of the DT is visibly flexing if you grab the bottle cage and wobble it, so I'm not surprised its come loose, but I could do with a fix that means I don't end up ripping the whole cage off the DT when rattling down some alpine pass in the next week or so.
I've spoken to the shop I got the frame from (Keep Pedaling) and they've got the warranty process underway very promptly, but there isn't an active importer at the mo, so a replacement in the near future isn't an option. I do have permission to bodge as needed, and the suggestion was epoxy, but I'm not sure how I can apply it in a way that won't crack off again due to the flex in the DT. The boss stands less than a mm proud of the DT, so there's not much to work with. It feels like trying to puddle enough glue on to counteract the flex will be a fight I can't win - especially as I'll have to sand all the lacquer off to get it to stick to the carbon.
I've got the cage remounted and used the bike on a bivvy last night and nothing fell off, so I'm probably overworrying - but the trip is (and has been for a while) a big thing, and the frame being "broken" before I start is stressing me some...
Ideas..?
Thanks
Given the number of bosses on a Warbird, can't you use a different pair?
Otherwise, fit the cage and wrap a strap round the frame and cage mount (possibly the bottle too) to provide some support .
Is it a rivnut type insert? If so a bolt and nut might be able to get it to expand into the frame enough to hold properly.
If you want to mount the cage in the same place but not risk the current bosses, how about using a couple of 'mount anywhere' bottle cage mount strap type things
Something like these Zefal Gizmo bottle cage mounts
as per blaggers - if it can spin it suggests its a riveted in insert rather than welded/braised and the rivet just hasn't quite been set tightly enough
Normally they're fitted with a special setting tool but you can do it with a suitable nut and bolt and two spanners - this video below maybe useful as it effectively shows you what would be happening inside the tube so you can see what you're trying to do with the nut and bolt.
I would work in tiny increments as cycle tubes are so thin so I'd image the margin between loose & spinning and over-tightened & cracked the tube are pretty slim
You can get the right epoxy for carbon in things like fishing rod repair kits, easily available and stronger than the super glue. And a few zip ties round it as well won't hurt
I'm not sure how I can apply it in a way that won't crack off again due to the flex
epoxies are quite different to CA suplerglue stuff, which is very very brittle. im not sure about the chemistry of CA, but i think its more about bonding the two materials, so the less you use the better. The glue itself isnt inherently strong * (* - though there is a strong possibility im talking BS)
Can hold the stand in a frame with the bottle boss facing downward, then use a syringe to puddle epoxy up through the hole, so that it forms a puddle around the boss on the inside surface?
another you could try, using the same method, is gorrila glue (original). That stuff flows like honey, but foams on contact with moisture so expands to fill gaps and create a tough fillet. you coudl use a spray bottle to wet the inside surfaces, or you can even mix a few drops of water with the glue before you inject it to really get it going.
you may need to then retap the thread, but thats easy enough, even if you have to make a tap by slotting an old bolt.
We use this at work for similar repairs if you can't get in to replace the rivnut and it's nothing safety critical, it looks like the same brand also does a semi-flexible adhesive but that might not be necessary as it's not really a moving area it's probably just that you didn't have much in the way of contact or adhesion using regular superglue on an un-prepped surface. This will be more forgiving:
https://www.easycomposites.co.uk/permabond-ET5428-black-epoxy-adhesive
https://www.easycomposites.co.uk/semi-flexible-15min-epoxy-adhesive
Jon are you in Sheffield?
OP here...
Well the update is that I'm just gonna wing it.
When I tried to remove the old bolt, it unscrewed maybe 5 or 6 turns then jammed and started spinning the boss - easily enough it took a few turns for me to realise. Being unable to grip the boss properly with the cage and pump mount in the way I ended up sawing the bolt head off, then slotting the end of the stud to try and unscrew it. No joy, as I still couldn't grip the boss tightly enough to stop it spinning.
I did ask the guy at the shop if they were Rivnuts, but he reckoned not, otherwise I would have tried squishing it down tighter again.
I've ended up reinstalling the cage held in with a nut on the stud. This tightened down Ok, and I rode on Saturday with a full bottle in it to no obvious change, so fingers crossed. I'll just plan to empty that bottle first to reduce the load on the bolt!
It feels like if I hadn't tried removing the bolt I'd have been blissfully unaware of what was going on and it would all have been fine. I'm going to have a spare Voile strap with me, cable ties, tape etc. Worst comes to it, I'll take all the stuff out of my tool keg and redistribute it around the bike; ditch the keg and stick the bottle in that cage under the DT and keep the second bottle on the ST. (the 4th set of bosses up at the top end of the DT are hidden by my frame pack). Be a pain swapping bottles, but not super-problematic.
Once I'm back, depending on what the turnround time for a replacement frame is, I may consider sending it to someone like Carbon Wasp for a proper repair, assuming its not going to turn into £100s .
I've a rivnut gun if you want to try it plus associated rivnuts
@bikerevivesheffield - thanks for the offer, but its already packed up in the bike bag now - and I'd have to get the stud out before I could use the rivnut gun! Might be back in a week or 2 if it does rip out though!
What about taking the bottle cage off and buying one of the universal mounts that straps to the frame instead