Viewing 40 posts - 1 through 40 (of 57 total)
  • That could have gone badly – cracked stem.
  • Premier Icon porkscratching
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    I just hit a pretty hefty pothole on my dark Devon country lane commute and this happened.

    Big crack noise and felt bloody scary.

    It was a Ritchey classic 130mm stem on a Surly Pacer steel fork. Had to walk the last mile with no steering. Stem bolts tightened to 5nm with Ritchey’s own brand torque key.

    So – what 120mmish road stem in polished silver should I get that won’t try and kill me?

    Premier Icon cloudnine
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    Surprised it didn’t completely buckle your front wheel…

    Premier Icon PJ266
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    Yeeeeesh, Ive got one of them on my tourer/gnarmac/bike bike.

    Glad you didnt get hurt.

    Premier Icon porkscratching
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    That’s the weird thing, front wheel still perfectly true and tyre is fine.

    I got the stem off eBay a couple of years ago and its probably done 6000 miles on the bike since then, still wouldn’t expect a catastrophic failure like this though.

    Premier Icon njee20
    Full Member

    That the two parts of the clamp are touching suggests to me it’s been overtightened at some point, and the failure mechanism supports this. Perhaps the previous owner did so if you’ve not.

    Premier Icon porkscratching
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    Fairly certain they weren’t touching before the crack, think that closed once tension released, but yes there is an unknown history.

    Premier Icon kazafaza
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    Wow, I’d check the tool for calibration – I’ve heard of another failure(although to the dropper seat post) that might have been caused by 5Nm Ritchey Torque tool.

    Premier Icon Teetosugars
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    So – what 120mmish road stem in polished silver should I get that won’t try and kill me?

    Thomson X2.

    Premier Icon shermer75
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    The scale on that road looks to be about 1:50 so at least walking a mile wouldn’t have taken long 😉

    Premier Icon porkscratching
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    Taken it off now – it’s proper broken:

    @shermer75 ha – that’s the handling circuit, or it might just be very very far away.

    Premier Icon amedias
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    Odd that both parts broke top and bottom in the same way… 😯

    I could understand one, but not both at the same time unless as suggested previous history of being over-tightened. Those stems are light, but not scary light.

    Do you think/does it look like there was a pre-existing crack there that then fractured properly with the pothole impact or does it look like spontaneous fracture?

    Glad you’re OK, front end failures are never fun and often end worse than just having to walk home.

    Premier Icon nickjb
    Free Member

    Do you think/does it look like there was a pre-existing crack there that then fractured properly with the pothole impact or does it look like spontaneous fracture?

    A close up of the fracture surface would help there

    Premier Icon porkscratching
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    I haven’t had the stem off since about about March and have maybe checked the bolt torque once since then with the torque key, but it hadn’t loosened. I’m guessing a previous history of overtightening then just metal fatigue from pulling and leaning on the “stretched” alloy. At 130mm there’s a fair bit of leverage there.

    I certainly haven’t inspected it for cracks so it may have been going for some time. The top cap kept it all together fortunately so it was just lateral movement, if it hadn’t I’d probably be visiting the dentist today.

    Premier Icon aracer
    Free Member

    Matt wrote:

    Those stems are light, but not scary light.

    I have a WCS which is far lighter 😯

    Though I guess it may also be made of stronger stuff.

    Premier Icon lunge
    Full Member

    Jesus, that is lucky/unlucky.

    Re. replacement, Holdsworth at Planet-X for £20?

    Premier Icon porkscratching
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    My phone is rubbish at close ups:

    Premier Icon aracer
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    Not rubbish at all – I’m no expert, but from my relatively limited knowledge that looks a lot like fatigue failure – ie there have been cracks growing for a while.

    Premier Icon amedias
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    that looks to me like it’s been cracked for a while…

    Premier Icon nickjb
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    that looks like it’s been cracked for a while…

    +1

    Premier Icon porkscratching
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    The cracks look a lot cleaner to the eye – they look dirty/greasy in the picture. You’re probably right though. The wheel is fine so the hit wasn’t that heavy – it was almost definitely on the way out before.

    @lunge the Holdsworth looks like it’ll do nicely and it’s less than half the price of the Ritchey. I think it’s the same as this Velo Orange one: http://www.veloduo.co.uk/products/velo-orange-threadless-ahead-stem-1-1-8-6-deg-rise?variant=16285019015 but cheaper.

    Premier Icon therevokid
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    crumbs … glad you’re ok (runs off to check wcs stems !!)

    Premier Icon supersessions9-2
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    nasty.

    nitto ftw.

    Premier Icon thomthumb
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    could it be a fake?

    there’s a lot of fake ritchey stuff on ebay.

    Premier Icon n0b0dy0ftheg0at
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    Let that be a lesson, always carry a spare stem, with a spare tube wrapped around it, under your saddle. 😉

    You survived to recount the tale, happy days! 😆

    Premier Icon Daffy
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    Silver Thomson?

    Premier Icon DiscJockey
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    Glad you weren’t injured 😯

    I’m speculating here, but if the previous owner’s bike had too short a steering tube, and they over-tightened the upper bolt (and then did the same with the stem flipped over) it would have severely over-stressed the lugs.

    RE: what to buy – as above, Thompson are proper stems, and come in 110/120mm, 0 or 10 degrees for both their X2 and X4 range.

    Alternatively, Hope’s XC stem comes in 110mm at 0 degrees, and they certainly used to do it in silver, although I couldn’t find anything listed via on-line shops. As with Thomson, you can really trust something like a Hope stem.

    If you’re on a budget and willing to risk a 2nd hand purchase, RaceFace used to do their Deus XC stem in nice chrome, in longer lengths.

    I’m slightly paranoid about steering security (hence the reason this topic attracted my attention so much !) so I only fit MTB stems on my road/CX bikes, but that’s just personal preference 😉

    Premier Icon porkscratching
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    Don’t think it was fake, it came “lightly used” and the seller had realistic other items and didn’t seem to be a trader.

    The Thomson looks a bit spendy and from the pictures seems to be silver anodised rather than polished.

    Can only find one UK seller for Nitto Threadless stems, and again spendy.

    I’ll probably give the Holdsworth a go, don’t think I’ll go second hand again!

    Premier Icon medoramas
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    Like new!!!

    Premier Icon dragon
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    Dunno why you think the wheel being fine is odd, if you hit the pothole square it should be ok. Where as it seems pretty clear that stem was already showing signs of failure.

    Premier Icon Stevet1
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    I’ll probably give the Holdsworth a go, don’t think I’ll go second hand again!

    Except it’s not a holdsworth, it’s a planet-x stem with a fancy name. Still should be fine.

    Premier Icon nickjb
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    Not sure I’d be ‘upgrading’ to a thomson. Have a google for cracked Thomson stem for dozens of pictures.

    Premier Icon porkscratching
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    Yeah, I know it’s not a real Holdsworth, but it seems to be a generic (probably Chinese) stem rebranded as Holdsworth, Velo Orange and Zenith in different places. The Planet X one seems cheapest.

    I’m not worried about light weight on this bike, it’s probably a bit thicker than the lightweight stems, so it’ll do. Correctly torqued from new, its very unlikely this’ll happen to any other stem.

    Premier Icon thisisnotaspoon
    Full Member

    I’d go with overtightnened too, I’m >100kg and have been using Ritchey bars, stems and seatposts since the 90’s (I’m a bit of a fanboy) and never had an issue.

    I’d just replace it like for like.

    The wheel is fine so the hit wasn’t that heavy – it was almost definitely on the way out before.

    Wheels are very strong axially, plenty of photos about of bikes ridden ito cars, writing doors and bumpers off, or even folding the downtube of the bike, but the wheel remains fine.

    Not sure I’d be ‘upgrading’ to a thomson. Have a google for cracked Thomson stem for dozens of pictures.

    Cracked anything will always find examples.

    But like Ritchey, Thompson are often faked too. they even bought a few and made an article about testing them to destruction alongside the real thing.

    Premier Icon nickjb
    Free Member

    Cracked anything will always find examples.

    Probably, although as a quick test I just googled cracked easton stem and got lots of pictures of cracked thomson stems 🙂

    Premier Icon porkscratching
    Free Member

    A bit of an update on this…

    So, against my initial better judgment I got another Ritchey Classic Stem as I assumed over-tightening had been the fault (and it matched my seatpost).

    Guess what happened to my new (36 day old) one on the commute this morning: small pothole, 2 loud cracks – almost identical breakage and a mile to push my non steering bike to the office.

    This one was a new slightly updated version from Wiggle on March 1st 2017. It was tightened using the same Ritchey 5nm torque key. Even if the key is faulty you still can’t get much torque on with 2 fingers due to the design, and all other bolts tightened with it felt fine on removal. The gap between the top of the steerer and the top of the clamp I measure at 3mm although this would have been slightly less with the top cap clamped down.

    Since my bike and I are the common factors I can only assume its my weight (90Kg) riding position/style (heavy on the arms) and heavily potholed Devon lanes. Thats not excusing these failures though – this is clearly a design fault across 2 updated versions of the same stem.

    I may well be dropping Ritchey an email about this and Wiggle will be getting the return.

    Here’s some pictures:

    I probably wouldn’t buy one of these if I were you.

    Premier Icon mildbore
    Full Member

    Wow, that could have been so nasty. Twice is inexcusable, definitely contact Wiggle and Ritchey. I remember George Hinckley snapping a stem in Paris Roubaix a few years ago, snapped clean off, how he didn’t face plant I don’t know

    Premier Icon drlex
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    Coo! That’s a bit rubbish, and well done for not crashing. What’s the replacement plan? Somewhat concerned, as I’m just about to build a bike with a Ritchey cockpit.

    Premier Icon nairnster
    Free Member

    Apart from the stem. You are the common denominator.

    The gap from steerer to top of stem looks quite big to me. Certainly more than i ever leave.

    Could it be that stem is very susceptible.

    Premier Icon bigyinn
    Free Member

    There are two possibilities here.
    Stem has been over tightened (Torque tool is faulty?).

    Stem inherently weak?

    Id say 2-3mm from the top of the steerer to the top of the stem seems reasonable to me.

    Premier Icon wwaswas
    Full Member

    For carbon forks everyone recommends having a 5mm spacer on top of the stem to give the stem something to ‘grip’ and not crush the top of the steerer tube.

    I wonder if the top of your steerer tube is flexing under load and the stem then cracks as it’s a brittle material?

    I put a spacer on top of all my stems now (whether they have a bung or an SFN) so the stem is entirely over the steerer tube.

Viewing 40 posts - 1 through 40 (of 57 total)

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