Anyone had a stem shear off?

proto

Bit of a guess on what really happened but came a cropper on Sunday. Doing 12mpg (guess) when I hit a major pothole which pretty well stopped the bike dead. Launched me out of my saddle and all of my weight was taken on the lever hoods. I think the back wheel then hit the same hole which caused me to press even harder on the bars, there was a horrible cracking noise and I found myself on the deck. The stem had failed just in front of the steerer tube, sheared off. Carbon stem.

I've never broken a stem before, in fact never even seen a broken stem before. Have I lived a sheltered life or does it just not happen? Anyone else broken one?

FWIW first and last time I'll use a carbon stem. Premier brand aluminium from now on.

imposter2.0

I suppose most things will break if you put enough pressure on, so it's certainly possible. Would be interesting to see a pic if you have one?

navrig2

Was it a branded Carbon stem or an eBay special?

bianchimoon

one guy i was out riding with last week had had a call from a friend who's titanium stem had failed after hitting a pothole, put a nasty gash in his thigh as he went over the bars

PerformingMonkey

12mpg? I wish my Garmin recorded my mpg.

I think what has happened is fairly rare. As Navrig2 asks, was it a branded stem or an eBay special?

Glad that you weren't too badly injured.

proto

Bought second hand. Premier branded but of unknown provenance. Could possibly be a counterfeit product. I'll send it to the importer/distributor for their opinion.

I'm not seeking any form of compensation (except possibky the council for the condition of the road) but interested more out of curiosity. As I have posted, I've never broken a stem before, am I the first? Further, I believe carbon stems are not that common in the Pro ranks so maybe they have had problems. Dunno.

Matthewfalle

Second hand stem with unknown provenance and manufacture. Hmmmmm......

Personally I wouldn't be put off using another carbon stem with such outrage given those facts.

Never heard of a stem going before - steerers yes, stems no, so I would just go and buy a new decent one and ride on that.

Slo Mo Jones

proto wrote:

Bit of a guess on what really happened but came a cropper on Sunday. Doing 12mpg (guess) when I hit a major pothole which pretty well stopped the bike dead. Launched me out of my saddle and all of my weight was taken on the lever hoods. I think the back wheel then hit the same hole which caused me to press even harder on the bars, there was a horrible cracking noise and I found myself on the deck. The stem had failed just in front of the steerer tube, sheared off. Carbon stem.

I've never broken a stem before, in fact never even seen a broken stem before. Have I lived a sheltered life or does it just not happen? Anyone else broken one?

FWIW first and last time I'll use a carbon stem. Premier brand aluminium from now on.

When I was a kid, another kid from nearby hit a kerb full on, sten snapped off at the join to the steerer, and he got a face full of steerer tube. Blood, teeth averywhere. Many, many stitches.

rickeverett

Good set of Aluminium needed

weight penalty is minimal

rolf_f

proto wrote:

Bought second hand. Premier branded but of unknown provenance. Could possibly be a counterfeit product. I'll send it to the importer/distributor for their opinion.

Post a pic on here - the fakes are almost always easy to recognise. The paint work is usually a giveaway for a start.

proto wrote:

Further, I believe carbon stems are not that common in the Pro ranks so maybe they have had problems. Dunno.

Basically because there is no point to them. They are heavier, weaker and far more expensive than the lightest alloy stems.

src1

I was riding with someone when their stem, an ITM Big One, snapped off at the weld nearest the steerer tube.



Since then I've only bought one piece alu stems with no welds.

Monty Dog

Ritchey WCS or FSA? - plenty of knock-off copies out there