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Replacing the grinding BB on my allez with a tiagra one. Can't remember if they come with thread lock or not.
If thread locked presuming no need for grease but if the threads are dry do I grease or blue the lock?
I would always grease a threaded BB
Always grease if you want to be able to undo it again next time - I use a light, lithium grease and it's never done me wrong.
Quick Google and I'm seeing pre-applied thread lock on some Tiagras, but not all.
Don't really know about that BB, but SRAM GXPs spec grease and no mention of thread lock. Given the fairly high torque and the thread direction respective to crank direction, there shouldn't be a need for thread lock. I find standard thread lock is only really of use with low torques to stop them rattling loose. Though a higher grade for higher torques perhaps but I prefer grease or copperslip to ensure I can get the thing off again.
grease.
i use anti seize
Copperslip ftw. Grease is 2nd option.
If two metal parts sit together but are not expected to move - copaslip.
If two metal parts sit together and are expected to move - grease.
If two metal parts sit together but are at risk of coming loose - threadlock.
they usually come with green grease on the threads, always grease a BB
fan of light thread lock , acts as lubricant and stops corrosion.
nice and easy to come off and ensures it wont creak or come loose.
and ensures that removal will be a cinch in future.
Grease threaded BBs, except for the plastic cups on some (I assume this is an external threaded BB so grease both cups).
Copaslip is best, any grease will help, avoiding a steel/alu combination meeting is also a good idea but mostly easily doable in these days of alu frames and mostly alu bb cups. (I cried a bit when I had to spend £20 extra to replace an octalink BB with an aluminium shell as the cheapest place I could find one didn't have the right axle/shell width combination except with a steel shell :()
read up on galvanic corrosion.
if its a barrier between dissimilar metals then its threadlock you want.
if an extra 17nm (242 breakaway torque) is causing you issues i dare say the BB wasnt coming out without serious intervention anyway.
It's an odd thing - I always use copaslip on the cars, but never on the bike. It's not like I don't have a huge tub of it or anything, but I never think to use it on the bikes. I have a bit of a mental block around it.
I will make a note to use it more in future.
read up on galvanic corrosion.
if its a barrier between dissimilar metals then its threadlock you want.
Maybe, but when it comes to threaded BBs, I'm yet to have one seize that has been greased and only ever had problems with ones that have never been touched from new (and presumably assembled completely dry). I think I'd be a little wary of applying threadlock to a BB as I'd be worried about making it harder to disassemble when the time came to service it.
grease is better than nowt . its those saying use copperslip that galvanic corrosion was aimed at.. and those using lithium grease.
To be fair, opinions about what to use are like arseholes..........everyone has one.
Trying to work out what to put on the sliding pins on car brake callipers.
Red rubber grease? Apparently not according to some.
Copaslip? EBC give you a nice packet of 'caliper grease' which looks like copaslip. But copaslip apparently doesn't play well with ABS.
Ceratech? Like expensive copaslip for ABS cars, except no one seems to actually say it's safe on rubber.
And several other options.
In the end I just put them back without cleaning them, they seemed to be sliding freely enough!
Copaslip it is, have a massive tub from when I did the car's brakes. Overestimated the amount needed.
Copaslip will depend on what's already on the BB or copaslip regardless?
Have always greased BBs in the past, the thread lock was throwing me.
My rule of thumb, if you want to undo it at some point, grease it
galvanic corrosion
Only an an issue if you intend to immerse it in salt water and run an electric current through the frame.
Copperslip it. Then don’t worry about until the bearings are ****ed, then replace it.
"Only an an issue if you intend to immerse it in salt water and run an electric current through the frame."
Not factually correct.
Yes an electrolyte needs to be present ..... Not unreasonable to think that a bike might get salt water on it in winter.
Bam you have a transfer path for ions.
Ahhh Trail-rat, what if a PF30 alloy BB to a Ti bb shell? As lithium grease only was used on installation of mine.
Depends if you want it to creak or not .
My pressfit are fitted following praxxis instructions.no creaking.where as when greased they would dry out and creak after 4-6 months
So thekey is to re grease every few months or so I take it?
Just grease it, then leave alone until it needs replacement imo.
Wtf - have you ever heard of maintainence, remind me never to buy a bike off you lol
Do you really take out BB's purely to regrease the threads then?
I take them out if the bearings need attention, other than that the BB stays where it is!
anti seize, 2nd biggest cause of creaks from the BB is dry BB shell threads
No praxxis say loctite
Fills the gaps with something hard stopping movement and ergo creaks.
thisisnotaspoon
To be fair, opinions about what to use are like arseholes……….everyone has one...
Aye, but when one of those people is an ex bike mechanic with a good racing history and a proper engineering degree, he may just be worth listening to...
Copaslip it is, have a massive tub from when I did the car’s brakes.
Tubs of copaslip are like family heirlooms. My son will be getting one passed down to him on his 18th birthday
The new BB arrived yesterday and was fitted last night with...
A light smear of people grease I had in the tool box. The threads were pre coated with thread lock. No creaks anymore and the bike feels much smoother. Cheers all.
Purple grease.
If two metal parts sit together but are not expected to move – copaslip.
If two metal parts sit together and are expected to move – grease.
If two metal parts sit together but are at risk of coming loose – threadlock.
From onzadog above