Mountain Bike Reviews Forum banner
1 - 20 of 34 Posts

·
mad aussie
Joined
·
1,129 Posts
Discussion Starter · #1 ·
Yesterday at the MBAA state series race near Tucson I had my carbon handlebar snap in half on a downhill, sending me over the bars. Fortunately I am OK other than some bruising, trail rash and a stiff back from landing. The handlebar was a Salsa Pro Moto 31.8 carbon running on a Cannondale XC3 Si stem/steerer. I have been riding the bar for around a year, strictly XC and I weigh 140lb. I always use a torque wrench (Sears) to tighten the stem faceplate bolts to 5Nm. On inspection it appears that the very narrow area on the Cannondale stem that holds the bars caused indentations on the carbon, leading to delamination and failure. I would encourage anyone who is running the Salsa bars with the Si stem to remove them and carefully examine the back of the bars for signs of compression. I blame myself for this, I should have removed the bars a couple of times, at least after crashes and checked the back.
I know this one will get the anti carbon crowd frothing at the mouth, but want to make it clear I have been running Carbon bars for over 8 years with no incident, the only other sudden bar failure I had before that was with aluminium.
I am going to replace them with another set of carbon bars, but probably the Syntace Duraflite Carbon which has a Ti mesh on the center section to resist compression. In addition Syntace has a good reputation for testing their bars for durability and impact resistance.
Here are a couple of pictures of the failure. You can clearly see the indent the stem made on the bars from the back.

Kevin
 

Attachments

·
mnt bike laws of physics
Joined
·
2,752 Posts
Kevin, that is scary!!! I am very glad you are "OK". I had a season that went like yours is going. One thing after another happening. It is so awesome you have such an excellent outlook about it.

I have a 25.4mm carbon Salsa Moto bar that I haven't put on yet. Been running their aluminum Moto bar. Love the 660mm length. Only flat bar besides a custom Ti. of that length.
With a 25.4mm, the clamp is a little wider because of the spacer. Got the 25.4 because the 31.8 does not come in a 5 degree bend - only 11 or 17.

BTW, You crash??? I learn something new every day ;)
 

·
Super Moderator
Joined
·
6,783 Posts
Kevin, how can using a Torque wrench make such an indentation, still? I have a Ritchey WCS Carbon flat bar 31.8mm x 580mm x 5degree, and now I am nervous about continuing to use it. Tightening them to 5 Newton Metres.......is not that tight.
 

·
The Martian
Joined
·
1,200 Posts
Yikes! Glad you are ok Wombat.

FYI: I'm impatiently waiting on my new Pro Moto (aluminum) on your recommendation of a few months ago. Should be here next week! Can't wait to see how much better it makes life :)
 

·
mad aussie
Joined
·
1,129 Posts
Discussion Starter · #7 ·
eliflap said:
the point of broken is very closer to the stem area...
If you actually read my post you would see that I noted the stem had made indentations in the carbon, that is why it broke at that area. :rolleyes:
 

·
mad aussie
Joined
·
1,129 Posts
Discussion Starter · #8 ·
greenhill said:
just curious what your next set of handlebars will be???
Alu or CF?................or maybe Steel :D
May I quote my original post

"I am going to replace them with another set of carbon bars, but probably the Syntace Duraflite Carbon"

Do people read or just look at the pictures........???????

Kevin
 

·
Registered
Joined
·
246 Posts
Flying Wombat said:
bars for signs of compression. I blame myself for this, I should have removed the bars a couple of times, at least after crashes and checked the back.
Kevin
What kind and severity of crashes had this bar been in?
 

·
mad aussie
Joined
·
1,129 Posts
Discussion Starter · #10 ·
A couple of tumble down the hill crashes, slide outs etc. I strictly ride XC, but our terrain in Arizona is harsh and unforgiving for making mistakes

Kevin
 

·
Super Moderator
Joined
·
3,266 Posts
Zachariah said:
Kevin, how can using a Torque wrench make such an indentation, still? I have a Ritchey WCS Carbon flat bar 31.8mm x 580mm x 5degree, and now I am nervous about continuing to use it. Tightening them to 5 Newton Metres.......is not that tight.
I imagine it wasnt the tightening of the faceplate that caused the indentation...More likely the couple crashes.
I'm with Wombat. Reading the Whole post yields alot of answers!
 

·
Registered
Joined
·
321 Posts
I have a Lefty SL with the SI stem on my SS, and had to take the bars off the other day while working on the fork, and I noticed the same type of indentations. My bars are Easton Monkey Lite SL's. I've noticed a bit of creaking when really laying the power down, this really concerns me now. BTW I'm about 225.
 

·
mad aussie
Joined
·
1,129 Posts
Discussion Starter · #13 ·
Jay04cobra said:
I have a Lefty SL with the SI stem on my SS, and had to take the bars off the other day while working on the fork, and I noticed the same type of indentations. My bars are Easton Monkey Lite SL's. I've noticed a bit of creaking when really laying the power down, this really concerns me now. BTW I'm about 225.
Well my suggestion would be to replace them! I was actually pretty lucky, I am in pain today and can hardly move my back, but if it had failed on a super fast downhill.........

Kevin
 

·
Fo' Bidniz in da haus
Joined
·
17,282 Posts
...glad you are ok, and this is why (granted, low probability i am sure) i am selling my twice ridden carbon bars; dont need this in the back of my mind and no, this is not the first i have seen in terms of breaks
 

·
mnt bike laws of physics
Joined
·
2,752 Posts
from what I've seen, fo doesn't put much effort into his posts.
But, then again as he said, he only rode his bars twice, so mabey he is too busy posting...
 

·
Registered
Joined
·
246 Posts
Flying Wombat said:
A couple of tumble down the hill crashes, slide outs etc. I strictly ride XC, but our terrain in Arizona is harsh and unforgiving for making mistakes
Kevin
I know you know this already, no doubt, but you posted this experience of your's so I'll write this anyway: All handlebars ought to be replaced after a decent crash, you can't blame a specific brand for failing after a "couple tumbles down the hill".
 

·
Registered
Joined
·
321 Posts
WHY CAN'T PEOPLE READ!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

He's not blaming the handlebars at all. If you haven't seen a SI stem then you don't know that the backside of the stem opposite the face plate has much, much less material there that may be causing excessive force to be applied to carbon bars even though proper torque specs are applied to the face plate bolts. He's not blaming it on carbon bars, or a brand of carbon bars.
 
1 - 20 of 34 Posts
Top