[Closed] That could have gone badly - cracked stem.

Surprised it didn't completely buckle your front wheel...

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

Glad you didnt get hurt.

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.

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.

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

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 [url= ]5Nm Ritchey Torque tool[/url].

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

Thomson X2.

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

Taken it off now - it's proper broken:

[img] [/img]

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

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.

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?

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.

[quote=amedias ]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.

Jesus, that is lucky/unlucky.

Re. replacement, Holdsworth at Planet-X for [url= https://www.planetx.co.uk/i/q/STHOGS/holdsworth-gran-sport-stem ]£20?[/url]

My phone is rubbish at close ups:

[img] [/img]

[img] [/img]

[img] [/img]

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.

that looks to me like it's been cracked for a while...

that looks like it's been cracked for a while...

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: [url= http://www.veloduo.co.uk/products/velo-orange-threadless-ahead-stem-1-1-8-6-deg-rise?variant=16285019015 ]http://www.veloduo.co.uk/products/velo-orange-threadless-ahead-stem-1-1-8-6-deg-rise?variant=16285019015[/url] but cheaper.

crumbs ... glad you're ok (runs off to check wcs stems !!)

nasty.

nitto ftw.

could it be a fake?

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

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! 😆

Silver Thomson?

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 😉

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!

[img] [/img] Like new!!!

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.

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

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

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.

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.

Cracked anything will always find examples.

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:
[url= https://s2.postimg.org/tkbtd6h2x/IMG_20170406_083017416_HDR.jp g" target="_blank">https://s2.postimg.org/tkbtd6h2x/IMG_20170406_083017416_HDR.jp g"/> [/img][/url]

[url= https://s2.postimg.org/3q20neh2x/IMG_20170406_083427119.jp g" target="_blank">https://s2.postimg.org/3q20neh2x/IMG_20170406_083427119.jp g"/> [/img][/url]

[url= https://s2.postimg.org/4tm4zd1q1/IMG_20170406_082942170_HDR.jp g" target="_blank">https://s2.postimg.org/4tm4zd1q1/IMG_20170406_082942170_HDR.jp g"/> [/img][/url]

[url= https://s2.postimg.org/g78oakc8p/IMG_20170406_083003932_HDR.jp g" target="_blank">https://s2.postimg.org/g78oakc8p/IMG_20170406_083003932_HDR.jp g"/> [/img][/url]

[url= https://s2.postimg.org/sadzy4nax/IMG_20170406_083434403.jp g" target="_blank">https://s2.postimg.org/sadzy4nax/IMG_20170406_083434403.jp g"/> [/img][/url]

[url= https://s2.postimg.org/maq8uh2ih/IMG_20170406_084119860.jp g" target="_blank">https://s2.postimg.org/maq8uh2ih/IMG_20170406_084119860.jp g"/> [/img][/url]

[url= https://s2.postimg.org/p67xf2vw9/IMG_20170406_084112306.jp g" target="_blank">https://s2.postimg.org/p67xf2vw9/IMG_20170406_084112306.jp g"/> [/img][/url]

[url= https://s2.postimg.org/gp8f45r7d/IMG_20170406_084027863_HDR.jp g" target="_blank">https://s2.postimg.org/gp8f45r7d/IMG_20170406_084027863_HDR.jp g"/> [/img][/url]

[url= https://s2.postimg.org/lceh5xek9/IMG_20170406_084259576.jp g" target="_blank">https://s2.postimg.org/lceh5xek9/IMG_20170406_084259576.jp g"/> [/img][/url]

[url= https://s2.postimg.org/52ob313w9/IMG_20170406_085111985.jp g" target="_blank">https://s2.postimg.org/52ob313w9/IMG_20170406_085111985.jp g"/> [/img][/url]

[url= https://s2.postimg.org/6vr7rcp2x/IMG_20170406_085145961.jp g" target="_blank">https://s2.postimg.org/6vr7rcp2x/IMG_20170406_085145961.jp g"/> [/img][/url]

[url= https://s2.postimg.org/sw7k7z7qx/IMG_20170406_085136559.jp g" target="_blank">https://s2.postimg.org/sw7k7z7qx/IMG_20170406_085136559.jp g"/> [/img][/url]

[url= https://s2.postimg.org/cz8sb9fcp/IMG_20170406_084311483.jp g" target="_blank">https://s2.postimg.org/cz8sb9fcp/IMG_20170406_084311483.jp g"/> [/img][/url]

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

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

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.

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.

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.

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.

Don't buy used stems?.

Wheels are very strong axially

Radially, surely?.

Eeek, twice is a concern! 😯

Shocking! Once would be bad enough. At least it wasn't carbon.

Personally I avoid Ritchey stuff completely now. I have no idea how their (his?) stuff gets decent reviews, because the headset and clipless pedals I had (back in 2005 or something) both lasted about a month. The sealing on the headset was abysmal, and the pedal body came off the axle on a ride.

@mildbore I've ordered 1 of these - https://www.planetx.co.uk/i/q/STHOGS/holdsworth-gran-sport-stem. It's just rebranded Chinese stuff, but doesn't look like its trying to be too lightweight and doesn't have the diagonal closing that seem to cause the problem.

@wwaswas The steerer is steel and pretty damn thick (Surly Pacer Fork), I doubt its flexing that much.

@nairnster The gap is larger than I'd like, but 3mm should be fine and the top clamp bolt is well below it.

@bigyinn Even if the torque tool is faulty theres no way there was more than about 8nm on there I used 2 fingers to tighten it.

@Nobeerinthefridge the second one wasn't second hand

The Ritchey guidelines are [url= https://ritcheylogic.com/manuals/bars-stems/Ritchey_barstem_EN_2012_10_29_web.pdf ]on page 6 of this document[/url], and they specify that the gap between the top of the steerer and the top of the stem should not exceed 2mm-3mm, so the OP appears to have complied with Ritchey's own instructions.

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.

Not every manufacturer specifies that the steerer should protrude above the top of the stem, rather than the stem above the top of the steerer. For example, Trek does but Deda doesn't, and nor does Ritchey, and that inconsistancy between manufacturers for a safety critical part does seem odd and is frustrating to me as a consumer: presumably one way is right, or at least better engineering practice than the other.

Reading the guidelines, I note that Ritchey also recommend the use of their carbon paste, 'Liquid Torque' on carbon steerers, something which Trek and Specialized prohibit on the grounds that the paste may migrate down the steerer, and once it is below the steerer between parts that are not clamped on the steerer, such as the spacers and headset top cap, the inevitable tiny movements of those parts will cause the paste to act as an abrasive on the carbon steerer surface. I think Trek and Specialized are vastly bigger companies than Ritchey, and will have devoted more resources to these issues and be much more concerned about the risks of product liability for faulty parts and damage to their brands and sales, and so would be more inclined to follow their guidance rather than Ritchey's.