Snapped Stem - Oval R700

rlaner

Hi;

Has anyone had or heard of issues with a stem snapping while they were riding. The brand is Oval R700. I think this is a pretty good brand. I have had no prior major crashes but have done at least 10000 miles on my tri bike. It snapped and I went straight to the ground doing about 19 mph. The crash smashed up my shoulder & AC. I count myself lucky that it didn't happen on a downhill or a road that had more traffic. It could have been much worse.

I have had my bike checked before major rides and triathlons in past.

Does anyone know if stems should be changed out on a regular basis or after a certain amount of miles.



Rick

Sleeper Cell

Photos of the stem? How old is the stem? Where did it break? Did you fit it yourself or is it as it came from the factory? Which country are you in?

I have never heard of a stem snapping and I doubt there is a mandated life span on such an item. I think I would contact the retailer (it's their responsibility to deal with you (in the UK at least)) with your account of the events and ask them to resolve it.

Oh, and I hope you're back on your bike soon. Sounds like you had a lucky escape.

bigmat

Did the stem actually snap, or did the bolts fail causing the face plate to come off (and then the bars to fall off presumably?)?

I use Oval stems , mine all have the "reverse" bolts that go in from the back, bit of a faff and I ended up buying a special allen key specifically for the job. I could imagine someone making a bit of a mess using a standard allen key and potentially over/under torqing, cross threading etc.

Anyone, get well soon!

crankycrank

Yes, please post some photos. It's very rare that a stem will break and when they do it's usually (but not always) due to improper installation. If it's not too old or been crashed before yours broke and actually had the metal or weld break than you should have a case. Hope you heal up soon and get this resolved and wouldn't worry about it happening again as I have never known anyone personally that has had this happen with an alu stem without it being due to previous damage or not being bolted up properly.

Found this description of the R700 from a retailer in the US. "Oval Concepts R700 Road Stems are constructed of 3-axis net shape forged 2014 T-6 aluminum and are one of the lightest, stiffest and safest alloy stems available."

dj58

Would be interested to know were it failed, weld at steerer tube clamp, weld at handle bar clamp or did it shear inbetween?

rlaner

I think it snapped at the weld area.

rlaner

Added few more photos

rlaner

1 more photo

rlaner

Thanks for responding guys.

I will try to answer some of the questions in one go. Typing with the left hand only is a bit of a challenge.

It looks like it broke at the weld near the bar clamp.

I had the bike built new. Custom built by a bike builder in 2008. Cevelo P3 frame with durace 9000. The front bars and stem were all selected because they were considered medium to high end gear. We also selected the Alum stem because it is stronger. I had the bike built when I lived in Singapore. I now live in the US. I have done many half and full Ironmans on the bike in past 6 years. The roads in the area I ride in (Texas) are pretty rough. I would average 90 miles per week on the road on the tri bike. In the section it happened it is particularly rough.

I think this is just due to fatigue on the part and it is very rare. There are no other reports that I could find.

My first reaction was to just get the word out to check your parts if you ride a lot. I have a buddy that had the same bike built when I had mine built. He is changing that part.

Do you guys think Oval should know about this. I tried sending them a note via their contact page but it doesn't allow pictures. I have had no response.

Let me know what you think of the photos.

meanredspider

Are you near a university that might have an engineering or metallurgy department? Normally someone knowledgable will be able to tell you the failure mode pretty quickly by a quick inspection (maybe a peak under a microscope).

It does seem to me that the most likely cause is a manufacturing fault. I think you're very unlucky for it to have failed catastrophically - you'd have expected some sort of warning before it failed. Again, that leads me to believe there's a fault.

meanredspider

Looking at the pictures as well as I can, it looks as though it's failed in the "heat affected zone" of the weld (rather than the weld itself). Poor welding technique can cause this problem. I'd encourage you to have it looked at by someone with metallurgy skills.

BTW - it must have been a very nasty crash. Glad you aren't more badly hurt. Good luck.

Sleeper Cell

Wow. Epic failure. As said above, it looks like a manufacturing defect.

I would contact the manufacturer and ask them what the lifespan of this stem should be and where this information is made available to customers. Then, let them know what happened and give them the pics and let them respond.

damocles10

Food for thought. How long was the stem? My stem is over eight years old....I am going to check it out and other bits too. It must have been a real shock for the the stem to fail - I wish you a speedy recovery.

proto

There is no welding on an Oval R700 stem.

mr_evil

Reading the description of that stem, it sounds like Oval have tried to design it to avoid failures like this, so I'm sure they would very much like you to send this stem back to them for analysis.

meanredspider

proto wrote:

There is no welding on an Oval R700 stem.

There's welding or brazing in the picture so perhaps that's not the Oval R700 then

keezx

Oval Concepts R700 RBT Road Stem
New

enlarge item image

Great looking, reliable lightweight stem
Blablablabla
50-70mm lengths are welded construction, are 20-25 grams heavier and do not currently fit our Carbon/Ti, Aero or Stem Cap Aero Bar Systems

rlaner

My stem is at least 6 years old. On the web site the new stems look different.

Monty Dog

Looks like fatigue failure at the weld root, not aided by the extra leverage from tri-bars. Expect there was some creaking before it 'went' - judging by the state of the other bolts, amply helped by corrosion.