How long before replacing stem/hbars/seatpost

TheStone
TheStone Posts: 2,291
edited June 2013 in Road buying advice
Do these things have a lifespan?

Recently told it might be time to replace them on the good bike. They're around 7 years (25,000km) old.
Middle to high end aluminium stuff.

Also, what about the carbon forks?

The frame is Ti. Virtually everything else has been replaced due to wear, failure, crashes or just wanting to upgrade.

I ask now, as I'll replace cables, bartape etc after the marmotte.
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Comments

  • imposter2.0
    imposter2.0 Posts: 12,028
    TheStone wrote:
    Do these things have a lifespan?

    In short, no.
  • iPete
    iPete Posts: 6,076
    When you see a shinier/lighter/blinger one usually.
  • ugo.santalucia
    ugo.santalucia Posts: 28,325
    I do worry about aluminium bars... alloy suffers fatigue and if those fail, they do so quite dramatically... if in doubt, given the price of a set of alloy bars, just change them. Stems and seat posts are a safer bet.

    Composite has a better fatigue behaviour, so unless you see a crack, there is no need to worry
    left the forum March 2023
  • markp80
    markp80 Posts: 444
    edited June 2013
    I was wondering about this. I often ride my old Dawes, which has a lovely alloy stem and engraved handlebars (I think they say Milremo on them?). It's probably knocking on for 50 years old, and it suddenly occurred to me that these bits might be fatigued and suddenly snap. There's no issue visually that I can see, but it left me feeling a bit uncertain.

    Cheers,
    MarkP
    Boardman Road Comp - OK, I went to Halfords
    Tibia plateau fracture - the rehab continues!
  • markp80
    markp80 Posts: 444
    ugo.santalucia wrote:
    I do worry about aluminium bars... alloy suffers fatigue and if those fail, they do so quite dramatically... if in doubt, given the price of a set of alloy bars, just change them. Stems and seat posts are a safer bet.

    Composite has a better fatigue behaviour, so unless you see a crack, there is no need to worry
    You posted at the same time as me!
    So, I clearly need to worry! That's a shame, because as well as the engraved handlebars, the stem is a really pretty casting, with red painted patterns in it.

    Hmmm....
    Boardman Road Comp - OK, I went to Halfords
    Tibia plateau fracture - the rehab continues!
  • Sprool
    Sprool Posts: 1,022
    ugo.santalucia wrote:
    Composite has a better fatigue behaviour, so unless you see a crack, there is no need to worry
    Vastly dependant on quality and design of the composite part. When they do fail, they go spectacularly and without any early warning signs.
  • ugo.santalucia
    ugo.santalucia Posts: 28,325
    Sprool wrote:
    ugo.santalucia wrote:
    Composite has a better fatigue behaviour, so unless you see a crack, there is no need to worry
    Vastly dependant on quality and design of the composite part. When they do fail, they go spectacularly and without any early warning signs.

    Absolutely, but it's not due to fatigue... just crap engineering. What I mean is a twenty years old carbon handlebar is in principle safer than the equivalent alloy
    left the forum March 2023
  • ugo.santalucia
    ugo.santalucia Posts: 28,325
    MarkP80 wrote:
    I was wondering about this. I often ride my old Dawes, which has a lovely alloy stem and engraved handlebars (I think they say Milremo on them?). It's probably knocking on for 50 years old, and it suddenly occurred to me that these bits might be fatigued and suddenly snap. There's no issue visually that I can see, but it left me feeling a bit uncertain.

    Cheers,
    MarkP

    More than age is mileage... could be 100 years old but if it has only covered a few thousand miles, there is no problem at all
    left the forum March 2023
  • TheStone
    TheStone Posts: 2,291
    One of my main concerns is putting it back together in another country and finding out one of the bolts are threaded. The stem has just 2 bolts and is often detached for packing in box.
    exercise.png
  • imposter2.0
    imposter2.0 Posts: 12,028
    TheStone wrote:
    One of my main concerns is putting it back together in another country and finding out one of the bolts are threaded. The stem has just 2 bolts and is often detached for packing in box.

    It will only thread because of poor maintenance. In that sense, you are just as likely to thread a new stem as an old one.
  • keef66
    keef66 Posts: 13,123
    Imposter wrote:
    TheStone wrote:
    One of my main concerns is putting it back together in another country and finding out one of the bolts are threaded. The stem has just 2 bolts and is often detached for packing in box.

    It will only thread because of poor maintenance. In that sense, you are just as likely to thread a new stem as an old one.

    Bolts are meant to be threaded. I'm assuming you mean stripped...
  • imposter2.0
    imposter2.0 Posts: 12,028
    keef66 wrote:
    Bolts are meant to be threaded. I'm assuming you mean stripped...

    'threaded' is a relatively common term for 'stripped' - but if it helps your understanding, then yes, I mean 'stripped'.
  • Jim C
    Jim C Posts: 333
    A well designed seat pin will last forever.
    Alloy stems, id have few concerns, so long as the threads and bolts are in good condition, whether 2 or 4 bolt.

    Alloy bars, from experience, they tend to break from around 20k miles. Some last longer. I tend to swap mine around that time.
    Old style alloy bars, with a sleeve of alloy where the stem clamps on, I think they're unlimited life. That sleeve spreads the stress load at the danger point.

    Carbon bars and stems- difficult to life, as it depends on damage. I don't use them for that reason. Plenty of light, cheap and safe alloy bars available
    jc

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