

Hey guys! Turning to you for advice on a bike i bought second hand. The stem is carbon and I've ridden it a few times, however noticed these "cracks" around the bolt holes after close inspection. Hard to tell how deep they are of if it's just cracks, however very SUS that they are all around each bolt hole. I'm kind of scared to ride it now however I have limited carbon fiber experience. Would you ride it or get it replaced asap? Have a planned group ride tomorrow
Thanks for your advice!
by AquaSpare
31 Comments
I have enough fake teeth, thank you very much.
Absolutely not.
I’d say ride on, but only with a full face helmet and thick gloves
100% NO!
No. Stems are cheap replacements. Teeth, skull, or other bones are far more expensive repairs. The rust in the bolt is a fine demonstration of neglect alone.
I’m all for second hand but not something I’d trust for a hard group ride without thoroughly vetting first. This could be a situation where it fails tomorrow or fails in 10 years. Hard to tell from just a picture alone but with used carbon, err on the side of safety.
NOPE
No. Replace asap. If it fails, it will fail without warning.
Stems are cheap. Dental work is expensive.
Toss on a cheap stem and inspect this stem in more detail after it’s off the bike. It doesn’t look good.
nah but i’d definitely invest in a torque wrench
Hells nah
+1 replace that stem
That looks ominous. How much weight did you save? I would replace it with an aluminum stem.
Ha. Looks like it was over tightened. Does it continue to grip the steerer? Do the bolts turn in the threads?
That would be on the short list for sure.
Based on your responses I’ll take the advice and get a new stem. Guess it’s mountainbiking for me tomorrow instead. Thanks for your input!
Yes just need to remove the tires from bike then just ride with rims as well
No.
I am a grumpy old retrogrouch, all metal bikes are heavier and slower, but so am I.
No, I wouldn’t ride a carbon stem. It might crack
>carbon
>cracks
No. Every time, no.
Easily replaced and cheap. Why risk it
No.
The answer to that question is almost always no.
Carefully examine the steerer when you replace the stem, it could be broken as well.
New stem day! Just get something good and fundamental like a Zipp Service Course that won’t crack
Riding cracked carbon fiber is like playing Russian Roulette.
Except instead of leaving one bullet in the gun, you only take one out.
I would ride it. With full motorcycle road rash gear.
Lol fuck that, if you think anything on your bike is cracked just dont risk it.
No
If you gotta ask……the answer is likely NO
Cyclist and mechanical engineer here. Noooo! That thing is already 90% fragmented. It’s going soon.
Absolutely fucking not.
Just try to imagine hitting a bump at 35mph in a descent and having your handlebar suddenly separate from the rest of the bike…
OceanGate would send it. Just sayin’.
Negative ghost rider.