A question of grease.

woodford2barbican
woodford2barbican Posts: 1,505
edited August 2007 in Workshop
I am building up a bike from the bare frame. I have got a fair idea of what I am doing, but since I am planning to learn by my mistakes this is not too much of a problem.

However, one thing I have very little idea of is, what should I lube and what should I lube it with?

From what I can see the bottom bracket needs some, as do the pedal threads, and the quill stem probably needs a bit. The chain obviously gets some - but even I know what and how there.

Any help gratefully received.

Comments

  • Hotblack Desiato
    Hotblack Desiato Posts: 136
    As temperatures and loads are generally low, you have a huge choice of grease.

    I use Finish Line Teflon grease. You can pick it up at your LBS or Halfords for about £5 a tube. Lasts ages.
    My Bikes:

    Road
    Dirt
    Fast
  • alaric@epicmtb
    alaric@epicmtb Posts: 80
    The recommended grease for cycle applications would be a teflon type, such as Finish Line - however you could use any multi purpose grease such as Castrol LM. Not as environmentally friendly, though...

    What should you grease? Anywhere there is metal to metal contact - all screw/bolt threads, seatpost, headtube faces...etc..Plus obviously packing the bearings!

    The only places I find it necessary to use threadlock instead is on the BB threads and on the crank bolt.

    Nothing should be assembled "dry".

    Alaric.
  • maddog 2
    maddog 2 Posts: 8,114
    grease on bearings, oil/lube on surfaces (chains)

    the "Nothing should be assembled "dry" comment is certainly open to interpretation :shock:

    bar/handlebar

    stem/steerer

    BB and cranks (square taper)

    mech to frame

    and plenty other places in between...

    If you never intend to do any servicing then by all means grease everything so it reduces the chance of seizing. If not then just use your common sense.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • aracer
    aracer Posts: 1,649
    maddog 2 wrote:
    the "Nothing should be assembled "dry" comment is certainly open to interpretation :shock:

    BB and cranks (square taper)

    Ooh, is that a metallic container of invertebrates I see there?

    FWIW I disagree with you on that particular point (though not wanting to start a war!)
  • Hotblack Desiato
    Hotblack Desiato Posts: 136
    ....then you come to putting titanium bolts into titanium threads and a whole world of trouble unless you use some anti-seize compound. sad-smiley-335.gif

    .
    My Bikes:

    Road
    Dirt
    Fast
  • pb21
    pb21 Posts: 2,171
    Use copper grease anti seize on bottom bracket threads.
    Mañana
  • John Stevenson
    John Stevenson Posts: 962
    The general rule is, if you want it to move again, grease it, and tighten it to the manufacturer's specifications. Aaaand if you're riding in corrosive conditions (such as UK winter roads) or joining exotica like titanium parts, use anti-seize.

    Let's deal with the one that crops up most often: square taper bottom brackets.

    The bolt on these things usually needs to be tightened to 35-50Nm. If the taper and the bolt are not greased, your torque wrench is not able to accurately measure the tightening torque; some of your effort is simply going into overcoming friction. The joint therefore won't be as tight as specified and therefore has a chance of coming apart.

    Once you're using a square taper crank and BB, the microscopic movement between the crank and axle will push the grease out of the interface anyway. That movement produces the fretting rouge that you find inside these joints when you take them apart after they have been ridden for a while.

    So it doesn't matter much in the long run if you grease a square taper BB, but it will make it easier to get it on properly tight in the first place, and that will keep your cranks in place.

    Another one of maddog's list: the stem/steerer interface. This needs to be able to move freely so that when you adjust the top cap it can move and preload the bearing. A small amount of grease in there is therefore obviously required.

    Over the years I've been lucky enough to get to know several bike mechanics who have backgrounds beyond the myth-propagation factories that are bike shop workshops.

    These are guys who have backgrounds as, for example, military helicopter technicians, racing motorbike mechanics or high-performance car techs.

    To a man or woman they think it's hilarious that bike mechanics believe that some things should not be greased.

    I don't know where these myths get started, but for metal-metal joints you want grease. Simple.
    John Stevenson
  • rustychisel
    rustychisel Posts: 3,444
    john_stevenson wrote:
    ... they think it's hilarious that bike mechanics believe that some things should not be greased.

    I don't know where these myths get started, but for metal-metal joints you want grease. Simple.


    Sorry John, you may call it a myth, but other people call it the official Campagnolo Technical instructions on square taper crankset assembly, which specify a dry and clean prep, ie NO GREASE.

    http://www.campagnolo.com/techinfo.php?did=f

    FWIW: I agree with you, I always assemble mine with a thin smear of grease because that's what I was taught, I'm obstinate, and I like things to come apart as easily as they were assembled.
    - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    I\'m only escaping to here because the office is having a conniption
  • John Stevenson
    John Stevenson Posts: 962
    rustychisel wrote:
    people call it the official Campagnolo Technical instructions

    Which just demonstrates that these things end up all over the place. My guess: those instruction sheets are written by the US marketing department (look at the number of legal warnings all over them) and not by any engineers.
    John Stevenson
  • rustychisel
    rustychisel Posts: 3,444
    Yup. Or at least with the US market in mind...
    - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    I\'m only escaping to here because the office is having a conniption
  • alaric@epicmtb
    alaric@epicmtb Posts: 80
    I was about to prepare a response and see that International Editor has done all my work for me!

    :lol:

    I learned most of my bike mechanic skills from my father, who is an engineer. Don't try to talk to him about not greasing things...

    Titanium does need special attention, but you still don't assemble it dry.

    Alaric.
  • aracer
    aracer Posts: 1,649
    Blimey - we seem to have a consensus on here! Nobody want to explain why we shouldn't grease the tapers?
  • ddraver
    ddraver Posts: 26,697
    don't forget to put some on your shoe cleat bolts too......
    We're in danger of confusing passion with incompetence
    - @ddraver
  • maddog 2
    maddog 2 Posts: 8,114
    Campag, FSA, and Shimano all recommend no grease - see their websites - not just some marketing department.

    I'm happy to go with the manufacturers of bike parts rather than helicopter mechanics.

    But this has been done to death.

    As for greasing the stem/steerer, why would a loose stem struggle to move?
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • aracer
    aracer Posts: 1,649
    maddog 2 wrote:
    Campag, FSA, and Shimano all recommend no grease - see their websites - not just some marketing department.

    I'm happy to go with the manufacturers of bike parts rather than helicopter mechanics.

    So you think Campag, FSA and Shimano don't have marketing departments, or that there is info on their websites that didn't pass by said department? Personally I'd trust an engineer and standard engineering practice throughout the whole of the rest of industry over any information released by a bike company. Or to use anopther good example, perceived wisdom perpetuated by airlines about the need to deflate bicycle tyres - or do you also trust the airline policy (which may have been nowhere near an engineer) over basic physics?
  • Gussio
    Gussio Posts: 2,452
    Nobody has mentioned carbon/metal interfaces.

    I understand that you shouldn't grease carbon. An example being a carbon seatpost, which could suffer swelling and subsequent failure.

    Is this correct?
  • maddog 2
    maddog 2 Posts: 8,114
    aracer wrote:
    So you think Campag, FSA and Shimano don't have marketing departments

    what are you on about?

    Read what I said. Then say something sensible.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • aracer
    aracer Posts: 1,649
    Maybe you should just read the previous posts properly and work out where the first mention of marketing departments came in if you're suggesting that said bicycle companies' information releases is more authoritative than "some marketing department".
  • woodford2barbican
    woodford2barbican Posts: 1,505
    Thank you for the advice - some helpful stuff in here, especially from Mr International Editor.

    Now all I need to do is buy the grease!
  • pieinthesky
    pieinthesky Posts: 417
    I remember a story from my dim and distant college days about an Engineer who tightened some diesel engine cylinder head nuts to the correct torque having greased them when he should not have done. The tie rods were overstretched as a result and snapped shortly after.

    So I would say there is no hard and fast rule. Best to read the instructions.
  • John Stevenson
    John Stevenson Posts: 962
    maddog 2 wrote:
    As for greasing the stem/steerer, why would a loose stem struggle to move?

    You've never seen a combination that was a snug fit?
    John Stevenson
  • aracer
    aracer Posts: 1,649
    pieinthesky wrote:
    I remember a story from my dim and distant college days about an Engineer who tightened some diesel engine cylinder head nuts to the correct torque having greased them when he should not have done. The tie rods were overstretched as a result and snapped shortly after.

    So I would say there is no hard and fast rule. Best to read the instructions.

    I can only imagine that was a tale told by a bike mechanic. In the world of real engineering you always use grease for things like that, as otherwise the amount of stretch is horribly inconsistent and dependent on the friction in the interface (torque isn't actually that great a measure, but it's the only useful one we have).
  • leonlikestrees
    leonlikestrees Posts: 528
    so would you even grease the handlebar/stem interface?

    I never have - I've always been worried the bars would slip. In fact, same goes for most clamps - brake levers, gear shifters, etc? Not saying that's right, just what I've done. ANd that might all change after reading this thread.

    Regarding carbon parts - I use some fancy Tackx 'not greas' that's designed for carbon parts. It has tiny squishy balls in it which compress when the clampst are tightened, holding it all together that little bit more. It's designed so you can torque up the bolts less, but I also use it on things like troublesome seatpost frame combinations that would slip down otherwise.

    Leon

    (not an engineer, so everything I say could well be cobblers!)
  • aracer
    aracer Posts: 1,649
    Personally I've never used grease on handlebar/stem clamps or brake lever/shifter clamps. Given you're trying to create friction there it would seem counter-productive. Never used grease on stem/steerer either, though I can see John's point (personally with snug fitting stems I usually use the reverse threaded bolt and penny trick to open up the clamp area a bit). The tacx "not grease" would probably work well on these interfaces.

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