Ooops...You think the lever was on too tight

[Thewavebb]

I was out on a ride at lebenon this morning with a friend of mine. He had bought a monkey light carbon bar about 3 weeks ago and did the install himself. Well today he wiped out on one of the jumps at leb and when he went to inspect the damage this is what he found....

http://i16.photobucket.com/albums/b41/uberben/oops1.jpg

My question is do you think the brake lever was install too tight which lead to a more probable chance of failure. I have a Race face Air alloy bar and from now on I think i will stick with similar bars.

~Ben

[TML]

Dang.

How's your buddy Ben? Hope he is allright. Leb is really dishing it out lately.

I do think it had something to do with the brake lever mount. Check the inside of the brake lever clamp to see if there are any unusually sharp edges.

[Tetreves]

My question is do you think the brake lever was install too tight which lead to a more probable chance of failure. I have a Race face Air alloy bar and from now one I think i will stick with similar bars.

~Ben

Could be...

It also could be that the bike caught on an immovable object (like a tree, or the ground) and the weight of his body on the grip forcing the bar forward caused it to break at the weakest spot. The handlebar could be supported by the grip and brake, making the weak spot where the handlebar is bare. Simple leverage...

Could be a combination of the two.

I'll stick with my aluminum bar for now...:D

[Thewavebb]

He seemed to be well enough. Bummer was that he had to go to work after all that. Hopefully he has paid he dues for the year and get get back on the saddle soon. I was just amazed at how easy it broke. I have crashed way harder and never had an issue. I am think of replacing my bar and stem though, this is its 5th year in operation and I wouldn't mind getting something new.

[Konaboy]

My question is do you think the brake lever was install too tight which lead to a more probable chance of failure. I have a Race face Air alloy bar and from now one I think i will stick with similar bars.


From everything I've read the torque wrench is your friend if you have carbon parts. If you go over the part's recommended torque range you will damage it.

FYI - Last year I witnessed a buddy's aluminum handlebar break by the stem going over one of the log piles at Leb. It could have been ugly but fortunately it wasn't.

[Burke]

Too tight? Hard to say... Having something clamped onto a handle bar adds stress, regardless of the material. The bar might have failed at a different spot if there were no brakes or shifters clamped to it; likely at the stem interface.

[berrywise]

I used to make it a habit of leaving my levers a little loose so that they would spin on the bar instead of break. Now I'm such a good rider I just never crash so I don't have to worry about it ;)

[stefan]

I heard that torque is very important on carbon. You also need to make sure that there aren't any burrs or sharp edges on the metal components you put on the bars, because scratches/gouges will damage the bar as well.

[col200]

I can see from the pic that you're using Shim. LX shifters. Those have rediculiously sharp edges on the clamp. I have those same bars on my HT and had to file the edge off of my LX's. I'm thinking either the juicy's or the LX's damaged the bar in some way when you installed them (scratch, crack, etc). Not only to the sharp edges create scratches, they also create a 'knife edge'. When The the bars flex (when Crashing) the sharp edge of the clamp is a perfect place for it to break off. Hope that helps explain it. Carbon is dang strong if properly installed (with a torque wrench), it's just not as forgiving as AL or Steel.

[nigel]

My guess is that the bar was "scored" a little and broke due to that. Ive been on carbon bars for a while and have yet to break one. Another thing to do is to always leave you shifters/levers a little loose, that is just enough so they dont move when you use them but if you crash hard they will move rather than break.

When he took the lever off was there any, even a slight depression under it the size of the clamp?

D

[SpecHR55]

Carbon fiber isnt the greatest for jumping/falling on.:hit: It broke in that area because the place where the lever is is the tightest spot on the bar besides the stem, even then... I dont know a whole lot about this but im just using common sense.

[col200]

Geez, makes me nervous hitting jumps with mine! :sick:

[Thewavebb]

I've sent him the link to this thread. I found this link on the trek webpage. Kinda outlines the Carbon fiber care issue.

http://www2.trekbikes.com/us/en/Inside_Trek/Misc/Safety_First_Carbon_Fiber_Crash_Replacement_and_Ca re_Information.php

[jeffgude]

I owned a pair of Profile carbon fiber bar ends a couple years ago. They last about 3 weeks. The first time I clipped a tree it crushed one of them. Carbon has a lot of fatigue resistance but very little impact strength.

[Heuy]

Alright, its time I weigh in yes it was me that broke my bars this morning. I read what people were posting at work today, but i didn't have my password memorized and my home computer has it in memory. I had to bite my tongue all day.

So here goes,

I actually read the instructions while installing the bars this winter (yes ladies however few of you would ever read anything on this site, men can read instructions):D. It said to make sure there were no sharp edges on anything you clamped onto the bar and to torque to manufacturers spec. Avid said snug for the brake levers. I am aware of the better to spin on the bar than break theory of mounting brake levers as Berrywise mentioned. So I tightened until I could sit on the bike and not rotate the levers with my fingers. however, the brake lever did bend a little in this crash. So it may have been a bit too snug, but I wouldn't want them any more loose. If they slide around on the bar won't that damage the outer sheet of the carbon?

I think I may have crashed harder than i realized, was kind of feeling it at work today. I also unloaded my bike tonight and saw that the stem had spun on the steerer tube a little (that's got to take some impact).

What I think,

Impact+200lb. rider+carbon bars=bad news

carbon bars save me a little over 40 grams. This is a little more than an ounce. For what it cost I should have went to the gym to shave grams instead of price point.

Pleas don't hate if you use carbon bars and it works for you. Just saying its not for me. I'm thinking of replacing w/raceface Deus xc risers. What do you guys think, also I'm pretty cross country so I'm not going to get something super burly.

[col200]

The Race face Dues XC's are great bars. I have them on my main rig. They just don't have the width and sweep of the easton carbons. dang it! I've never used the AL Easton bars but I'm assuming the geometry is the same as the carbons.

[Heuy]

hey thanks for bringing up geometry, man there's some differences in xc risers. This has reinforced my decision to get the Deuses. Easton aluminum bars are all 2" and more rise and more sweep. I'm trying to get away from my 23" width factory flats the 26" carbon bars were nice but I think 25" bars would suffice.

[bikeforlife]

I have a brand new unused pair of These (http://www.specialized.com/bc/SBCEqProduct.jsp?spid=14967) for sale if you are interested, Light strong and have pretty good geometry. Too bad about your broken bars though, breaking parts sucks since you can't ride and it can be expensive. Hope you find something that fits the bill of what you are looking for so you can get back on the trails.

[Thewavebb]

how much for the bars?

[bikeforlife]

PM sent let me know if you are interested in them or not

[Heuy]

rode the new race face bars last weekend, they're nice.

[crux]

Have ridden Monkey lites for years with out any issues and several diggers. From what I have seen the main reason that carbon breakes is due to point loading or a sherp edge. Consider this at each mechanical intersection of the bar, stem, brakes, shifters if any one of these components has a noticably sharp edge and digs into the carbon upon install you have just weakened the bar slightly at that edge, now if you strike a tree the bar is done.

Round all edges on alloy carbon interfaces by lightly sanding the edge of the alloy part smoothly then install the carbon bar. This method is fairly bomb proof and has not failed me yet.