Author Topic: Stuck Mercury EBB - what to do?  (Read 3391 times)

quilkin

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Re: Stuck Mercury EBB - what to do?
« Reply #15 on: September 06, 2021, 03:51:14 PM »
If it's two dissimilar metals coming together (Especially Steel and Aluminium) Then I'll use copaslip of some sort, and plenty of it. The copper contained in the grease acts as a "sacrificial anode".
Hmmm- I tried to read up on this, and found differering opinions - many saying that copper slip was only useful in hot conditions. I'll try to decide before I fit the new EBB.

Aleman

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Re: Stuck Mercury EBB - what to do?
« Reply #16 on: September 06, 2021, 04:06:27 PM »
You may well be right ... It just makes sense to me "metallurgically" ... It may well be that all it really requires is a normal grease with regular preventative maintenance, especially if used in wet and salty environments

PH

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Re: Stuck Mercury EBB - what to do?
« Reply #17 on: September 06, 2021, 08:42:49 PM »
If it's two dissimilar metals coming together (Especially Steel and Aluminium) Then I'll use copaslip of some sort, and plenty of it. The copper contained in the grease acts as a "sacrificial anode".
Hmmm- I tried to read up on this, and found differering opinions - many saying that copper slip was only useful in hot conditions. I'll try to decide before I fit the new EBB.
I hadn't heard that, but then I haven't extensively researched it, just looked and my tin says effective down to -40C and up to 110C
I've been using it on my EBBs since 2004 without any issue, though as I said they get serviced at least once a year, so it may be that any grease would have been OK.
What is it that these reports are saying?  That the solids are not required, or that there's a failure with the grease they're in? 
Alternatives would be any anti-seize grease, there's several cycle specific ones from the likes of Park Tools, but I have a suspicion that such specific  products are generic and rebadged with a considerable premium. 
I have a tub of waterproof marine grease which I use in other applications where keeping the water out is a higher priority than preventing seizure, usually around bearings, chances are it would be just as good in the EBB shell, but my tin of Copaslip will last me this lifetime so I have no incentive to try it.
I have a friend who swears by Vasaline, his bikes run perfectly so it obviously works for him.



PH

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Re: Stuck Mercury EBB - what to do?
« Reply #18 on: September 07, 2021, 07:49:44 PM »
BTW, does anyone know why Thorn use hex-head bolts for this? They need an 8mm socket which isn't part of a normal cycling toolkit. What's wrong with standard 5mm socket-head bolts, using a 4mm Allen key?
Yes - they're in just the right place to fill with muck which over a few month will solidify.  OK, probably never to the extent where you can't dig them out with a pointed object, but it's another job.  I have a small, good quality 8mm spanner that is fine, no need for a socket, it's in the touring kit because in the unlikely event of a shifting problem it'll change gear at the hub end.
I think Thorn have a preference for hex heads over socket heads on all the fittings, they certainly used to and you had to specify on the order form of you wanted cap heads.