Over tightened stem bolts cause big crash

[BMC - VTown]

My riding partner was chasing me down in a sprint when his stem bolts failed catastrophically at 53km/h and down he went on the tar, broken rib, collar bone and stitches in his elbow and shin, and much pain.

Make sure you stick to the manufactures recommendations on the nm torque settings for these critical bolts.

They range from 4 to 8 nm depending on the manufacturer specifications.

[Paul Ruinaard]

Win a. Tough lesson to learn.

 

Use a torque wrench

[Captain Fastbastard Mayhem]

What stem was it, and were they Ti bolts?

[Malpiet]

Very true, I seen during the argus a guys handlebar snap off clean just on the outside of the stem.

 

I found that my bars slipped when i hit big bumps even when torque to the specified NM,

 

removed the bars cleaned it up with degreaser and added some copper slip on the face plate and sides of and torqued it up, problem solved

 

Always advisable to get a torque wrench IMHO

[Oufy MTB (Roadie)]

stem bolts on my mtb only require 2nm, jip i think we overtighten in fear of it working loose

[Cat2forLife]

Happened to me once. Also at about that speed, but luckily I was coming to the end of a descent and only one bolt snapped, so no crash. Thank goodness.

 

All the best to your friend. Hope he heals up quick.

[Boerklong]

I put a drop of lock-tite on all the bolts of my mx bike... might do the same on the fiets on bolts that needs to stay put

[BMC - VTown]

It was a Deda stem on a Dogma frame, he was standing on the peddles at the time, went down real hard.

Yes torque wrench is required.

[BMC - VTown]

I prefer the all in one stem and bar system, carbon.

[openmind]

I use carbon paste on the stem / bar interface and torque to only 2/3 of the torque spec. More than tight enough and never slips. I use carbon paste even on Al /Al interfaces - works a treat.

[Cat2forLife]

It was a Deda stem on a Dogma frame, he was standing on the peddles at the time, went down real hard.

Yes torque wrench is required.

 

Mine was also a Deda stem. Maybe it's a Deda thing? Anyway, I also went for the integrated system afterwards. Got myself a FSA Plasma

[Seeker911]

Jees first time I ever heard of this happening. Yikes !! best I start using that torque wrench of mine.

[Skylark]

What exactly happened?

Did the heads of the stem bolts break off or did the stem itself or the faceplate have a catastrophic failure due to being over tightened? Tightening the faceplate unevenly can also crack the faceplate, I have done that on a Thomson stem before, wasn't even over tightened just unevenly.

[floatfox]

Torque wrench and lock-tite..dont use red lock-tite as you will possibly need to apply heat to get the bolts loose. Use only blue.

[Pieterg]

Eina !!

[Waynehans]

At least the Guy that fell is a BIG CHOP, so he will be OK!!! HAHA...