Viewing 19 posts - 1 through 19 (of 19 total)
  • Can copperslip cause threads to strip?
  • 13thfloormonk
    Full Member

    Sounds like a stupid question I know but I’ve now stripped threads out of two retaining nuts on the bottom of my Lake shoes. Pain in the hole as Lake won’t supply replacement nuts so I’ll need to butcher some woodwork T-nuts.

    I don’t use a torque wrench but I’m not a gorilla either, certainly never round bolts.

    Just have an image of copper particles somehow eroding the threads over time or something, better to use grease?

    trail_rat
    Free Member

    Loctite is the correct answer for this job .

    Copperslip won’t strip threads though

    PJay
    Free Member

    I think that greased threads turn more readily that dry ones giving the potential for over-torquing, but that does sound unlucky.

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    tjagain
    Full Member

    Cleat bolts seize a lot so coppaslip is good. They only need to be nipped up. Just tightish ie 4 or so nm. Very easy to overtighten if you use the long end of an Allen key.

    trail_rat
    Free Member

    Now then I challenge you to apply 4nm to a cleat and go for a ride.

    Then try and clip out they just move around.

    tjagain
    Full Member

    It’s about what mine are done up to. Finger tight then nipped up. Check the tables for torque values for bolts. I can’t link as I am on a phone.

    M6 is 4.5 nm

    trail_rat
    Free Member

    Shimano suggest 6nm

    Finger tight then nipped up also suggests you have no idea what torque you have applied.

    Torque charts for M5 countersunk socket head says typical max between 7-11nm pending grade and application

    tjagain
    Full Member

    Actually you develop a feel for the stretch of the bolt. 7+is way too much unless it’s hi tensile.

    I haven’t stripped a thread or had one come loose for decades.

    Onzadog
    Free Member

    Actually you develop a feel for the stretch of the bolt.

    Sorry, got to call BS on that. They nylon or carbon sole material will compress before the bolt stretches so even if you could feel it that accurately, you wouldn’t know what you were feeling the stretch of.

    Also, the contact edge of the cleat is serrated so unless that starts to dig in, it’s likely to slip around on the sole.

    jkomo
    Full Member

    A lubed bolt will take lower torque than the same bolt dry. Fact.
    What I was told by a man with TWO torque wrenches.

    mc
    Free Member

    Pjay has the answer.
    Any kind of lubricant is a friction a modifier, which means any kind of grease will mean you get more stretch on the bolt compared to a non-lubricated bolt for any given torque setting.
    Which in borderline cases, can mean the bolt/nut will strip/snap before reaching the desired torque.

    It’s also worth mentioning this is the reason why torque settings are only a rough guess, as the tensile result of torqueing a bolt to set value can vary dramatically depending on thread quality, materials, type of lubrication, and where lubrication is applied.
    This is why critical fasteners will often use angular tightening. You torque them to a specified value which is just tight enough to ensure everything is located, then you tighten them X degrees, which stretches the bolt a known amount, so you get a repeatable accurate tension in the bolt (if you want to get geeky, it’s known as Torque to Yield, and relies on the Hooke’s law/Young’s Modulus).

    TJ is right in that you do develop a feel for tightening bolts, however with cleats, they will settle into the material. Even if you were to torque them and leave them overnight, you’d probably get a bit more movement the next day due to the cleat settling into the material. Cleats are the kind of thing, where you really need to tighten them up, go for a short spin putting a fair bit pressure through them, then re-tighten them. Then you’ll probably find you can tighten them a bit more after the next couple rides before the cleats have finally settled in as much as they’re going to and don’t need any further tightening.

    alexnharvey
    Free Member

    Loctite is better for cleat bolts

    daviek
    Full Member

    No idea the material of the bolts but you’re not meant to use copperslip on stainless as it can cause them to pick up. Not sure if this still applies to tiny cleat bolts that aren’t much more than finger tight though

    bigblackshed
    Full Member

    Variations of the above is all correct when you are torquing a bolt into a quality threaded component. Different applications, different tensile strength bolts, lubed, glued, different shaped bolt head etc. will all use a different torque value.

    Now a pressed steel plate with some threads slapped in them, on the sole of a shoe, which in turn is then subjected to high torque twisting motion in its normal operation isn’t the going to hold up to precise torque settings on such a small thread.

    There’s far to much variation in cheap, uncalibrated torque wrenches to be real world accurate. Just apply copper slip so that you can undo them after a crappy winter and don’t go mad when tightening them up. If your stripping threads then it’s either suspect shoe plates or your going Hulk on them.

    mick_r
    Full Member

    Nm

    gofasterstripes
    Free Member

    Most of the torque applied to a bolt is lost to friction. Torque values for unlubricated bolts will be completely wrong if applied to lubed bolt as the lube will modify the frictional value significantly

    EG 10nm correct for your unlubed bolt then adding lube will reduce friction by, say, 50% you apply 10nm and overtorque the fastened by 100%

    PITA but tru

    thisisnotaspoon
    Free Member

    A lubed bolt will take lower torque than the same bolt dry. Fact.
    What I was told by a man with TWO torque wrenches.

    Grammatically at least you’re wrong.

    A lubed bolt takes (approximately) half the torque to do up as a dry one.

    “A lubed bolt will take a lower torque……” Reads like you think the lubed bolt will strip first. Although given sufficient thread then the shaft of the bolt would snap first I suppose.

    jkomo
    Full Member

    I meant what you said.

    13thfloormonk
    Full Member

    Thanks folks, I think the common factor is actually that it was the right shoe, which is the cleat I fiddle with most due to a sore knee. Maybe just one too many loosenings and tightenings for the thread…

Viewing 19 posts - 1 through 19 (of 19 total)

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