Author Topic: Seized grub screws on female bayonet - any tips?  (Read 2243 times)

butcherjms

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Seized grub screws on female bayonet - any tips?
« on: September 10, 2012, 04:22:05 PM »
Hi all

Does anyone have any clever tips for trying to prevent the 2 grub screws on the female bayonet connector from seizing?

After 15,000km, my shifter cable snapped recently while I was in the middle of nowhere in Panama. No problem, I thought, I have spare cables - until I found that the grub screws were completely seized, and quickly rounded when I applied any force with the allen key. So I had to get on the bus and order new bayonets from SJS, which have finally arrived in Colombia and I am about to fit with a new cable. All in all a real pain for something which surely should be an easy on-the-road repair!

It seems from other posts that this is a common problem. I took the opportunity to order a stash of (expensive) new connectors in case it happens again, but does anyone have any tips to prevent them seizing in the first place? I will definitely give them a good coating of grease - but has anyone tried using a different style of screw that is maybe easier to unscrew and less likely to round?

Many thanks,
James
www.big-sur.co.uk



Danneaux

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Re: Seized grub screws on female bayonet - any tips?
« Reply #1 on: September 10, 2012, 04:40:59 PM »
Hi James!

So sorry to hear of your trouble and inconvenience while on-tour, and the delay caused by it all. Your warning is a useful one for others. Perhaps some anti-seize on the threads of a new connector would be a wise course.

I have the EX box on my Nomad, but looking closely at the photos of the bayonet connectors on SJS Cycles' site...
http://www.sjscycles.co.uk/rohloff-bayonet-connectors-for-gear-cables-1-male-1-female-8274-prod11743/
...I don't see why one couldn't replace the recessed grub screws with standard headed allen bolts of the same thread, or even use hex-heads. One would need to use care to avoid over-tightening (a probable reason for the small-socketed grub screw), but an external head would allow purchase with mole/vise-grips or similar in case the worst happened and the socket rounded off.

Just a thought I hope might prove helpful.

Very best wishes on your fabulous tour; stay safe and sound!

Dan.

pdamm

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Re: Seized grub screws on female bayonet - any tips?
« Reply #2 on: September 11, 2012, 05:18:58 AM »
James

You could undo, regrease and re-tighten them as part of a regular maintenance routine to check they havenít seized up too much.

Dan

I started trying what you have suggested and installed some standard bolts.  I found that as the bayonet connectors go past each other the bolts stick out and run the risk of locking against each other preventing the gears from changing.  I think if I can source shorter bolts (or cut mine down to size) I may be able to get away with it.  I suspect if the bolts sit flush against the bayonet connector it may work.  However I havenít got around to doing that yet.

My motivation for trying this was to give me something easier to grasp hold of when reconnecting the bayonet connectors.  It is still on my to-do list.  In the mean time I have one standard bolt and one recessed grub screw on each side of each connector.  They are set up so the recessed screws on each cable face each other. That way the longer bolts point away from each other and donít catch when I change gears.

I hadnít thought of this as reducing the risk of a failure like James unfortunately experienced.  Now I have some more motivation to finish this task!

Peter
 

rualexander

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Re: Seized grub screws on female bayonet - any tips?
« Reply #3 on: September 12, 2012, 12:12:50 AM »
This is fairly a common problem I think, the grub screws are prone to seizing especially in the female bayonet connector which I think is aluminium rather than the stainless steel of the male connector. Greasing the threads is the best way to prevent it.
In an emergency situation I think you can get away with using a section of electrical cable connector such as these :
http://www.tlc-direct.co.uk/Products/TLCON2.html
Although it would mean removing the male bayonet connector as well and a maybe a new cable from the shifter to get the length right.
Worth carrying a few in your spares kit maybe.

sg37409

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butcherjms

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Re: Seized grub screws on female bayonet - any tips?
« Reply #5 on: September 14, 2012, 03:30:25 AM »
Thanks everyone for the help - the new bayonets have finally arrived and I will build a regular grease into the routine from now on to try and avoid a repeat! Now I just have to resolve my shifting cable issues - but I think I'll start a new post for that...

onebikeoneworld

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Re: Seized grub screws on female bayonet - any tips?
« Reply #6 on: April 13, 2014, 11:59:23 AM »
I've just had this problem and found a way to resolve it - an oven. I tried soaking them in WD40 overnight, but that didn't seem to do anything. I put the bayonets in an oven set to 250c for 10 minutes and 2 of the 3 stuck grubs came loose. Another 5 minutes got the other one loose. I know it's way too late for you, but hopefully this'll be good for anyone else who finds this post in the future with the same issue.

j-ms

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Re: Seized grub screws on female bayonet - any tips?
« Reply #7 on: July 05, 2019, 12:01:49 PM »
I am currently in a little village in East Lothian staying  with friends for a few days as part of our three month amble through the UK (see http://thorncyclesforum.co.uk/index.php?topic=13357.msg100295#msg100295). 

So I thought I would take the opportunity to change the cables on my Raven, since they are now over 22,000 kilometers old.

Same problem, and a bit more.  Grub screws stuck on one female bayonet and, on the one I got loose, the cable has fused to the insides of the bayonet.  I am guessing that this is due to galvanic corrosion caused by the interaction between the steel cable and the alluminium grub screws. 

The lessons seem to be  (a) always carry a spare set of bayonet connectors and (b)  occasionally loosen and tighten the grub screws and cable to ensure they don't fuse over time.

PH

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Re: Seized grub screws on female bayonet - any tips?
« Reply #8 on: July 05, 2019, 12:58:11 PM »
The lessons seem to be  (a) always carry a spare set of bayonet connectors and (b)  occasionally loosen and tighten the grub screws and cable to ensure they don't fuse over time.
Along with those lessons - c) replacing the grub screws with cap heads, as mentioned above, both allows a larger hex key and gives more grip when disconnecting them.  d) a chocolate box electric connector works as a temporary repair for most cycle cables, my Raven relied on one for gear changes for several hundred miles without problem.

Have you left it for now?  When you do attenpt it you could snip it off and leave it to soak in a jar of penetrating oil (Kano Aerokroil is my preference but I haven't tried many others)

j-ms

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Re: Seized grub screws on female bayonet - any tips?
« Reply #9 on: July 05, 2019, 09:25:54 PM »
I managed to source the female bayonet connectors from Bicycle Works in Edinburgh so I will be changing the cables tomorrow.  I am going to try and rescue the old bayonet connectors to keep as spares because there is always the risk this may happen again.