Mountain Biking - Do you trust your carbon handlebars indefinitely?

I've got a Specialized carbon handlebar on my 04 Stumpy and every so often I imagine going through a rock garden or somesuch other nightmare and having my carbon bars fail for no reason. The image is of me eating my Thomson stem with my teeth.

Do you trust your carbon bar indefinitely? Any evidence that I shouldn't? I'm sure I've dumped the bike a few times, though not sure what if any hit the bars have taken. I'm thinking about stepping up to a 31.8 stem/alloy bar combo since my setup is a 25.4 anyway.

I don't trust anything indefinitely.

I've got a Specialized carbon handlebar on my 04 Stumpy and every so often I imagine going through a rock garden or somesuch other nightmare and having my carbon bars fail for no reason. The image is of me eating my Thomson stem with my teeth.

Do you trust your carbon bar indefinitely? Any evidence that I shouldn't? I'm sure I've dumped the bike a few times, though not sure what if any hit the bars have taken. I'm thinking about stepping up to a 31.8 stem/alloy bar combo since my setup is a 25.4 anyway.

This has nothing to do with carbon, but 31.8 should be outlawed.

This has nothing to do with carbon, but 31.8 should be outlawed.

Any reason for that?

I think the best you can do is take the bar off and inspect it periodically for cracks.

Any reason for that?

because he doesn't realize that the 31.8 is actually stronger but hey...he's partying like it's 1990s.

Any reason for that?


because he doesn't realize that the 31.8 is actually stronger but hey...he's partying like it's 1990s.

It might be stronger, but it's overkill. How often to 25.4 handlebars break or bend when their 31.8 counterparts would have survived?

For road bikes, the larger radius can add comfort. For XC and AM riders, there is no real benefit.

because he doesn't realize that the 31.8 is actually stronger but hey...he's partying like it's 1990s.

I do realize that 31.8 is stronger and I would go there if necessary. But I prefer not to spend the money to replace my s-works carbon bar & Thomson stem with new stuff unless it's really necessary. But if the consensus is that people replace carbon bars every X years as a rule, then I would go ahead and get a new 31.8 stem at the same time and be even more sure.

I think that the handlebar is the single worst component to fail on a bike. Your entire upper body is relying on the bars being there. If they fail, you're going down and hard. Unless you get lucky :rolleyes: and your wheel turns and throws you sideways into who knows what, you'll go down right onto your stem and broken bars. That would not be good.

It might be stronger, but it's overkill. How often to 25.4 handlebars break or bend when their 31.8 counterparts would have survived?

For road bikes, the larger radius can add comfort. For XC and AM riders, there is no real benefit.

Is there a potential, with the added strenght, to make the bars lighter?

Is there a potential, with the added strenght, to make the bars lighter?

Typically 31.8's are a little heavier.

I don't trust anything indefinitely.

Ditto, there is no such thing :)

It might be stronger, but it's overkill. How often to 25.4 handlebars break or bend when their 31.8 counterparts would have survived?

For road bikes, the larger radius can add comfort. For XC and AM riders, there is no real benefit.

wrong

I think the s-works bars on my bike now are 160g (claimed). Specialized has a 31.8 alu bar that is 208g claimed and $40. Their 31.8 carbon bar is 195g so negligible. Hard to beat on price and weight. Anybody know anything lighter?

Carbon fiber is stronger than steel, or so they say. It is fine, until the Resin that holds it's integrity is cracked or chiped, then that becomes the weak point of the bar.
I'd say if you're truly bothered by the horrific images of your teeth becoming a thompson stem, then Inspect the handlebars throughly. try looking at all different angles in different lighting to make sure there are no cracks, chips, or stress marks/fractures.

I think the s-works bars on my bike now are 160g (claimed). Specialized has a 31.8 alu bar that is 208g claimed and $40. Their 31.8 carbon bar is 195g so negligible. Hard to beat on price and weight. Anybody know anything lighter?

$40 for a carbon bar? Show me.

"Specialized has a 31.8 alu bar that is 208g claimed and $40"

But, OK: http://www.performancebike.com/shop/profile.cfm?SKU=17671&subcategory_ID=5250

the riser one is $60 today, but tomorrow or the next day it'll be $40 and this one will be $30. I actually bought the flat bar one a few years ago for my hybrid commuter and it works just fine. Seems like I paid low $20s for it after all the discounts and such.

I never even think of my carbon bars. I guess I trust them enough.

Carbon fiber is stronger than steel, or so they say. It is fine, until the Resin that holds it's integrity is cracked or chiped, then that becomes the weak point of the bar.
I'd say if you're truly bothered by the horrific images of your teeth becoming a thompson stem, then Inspect the handlebars throughly. try looking at all different angles in different lighting to make sure there are no cracks, chips, or stress marks/fractures.

Thomson (http://www.lhthomson.com/stems.htm)

It might be stronger, but it's overkill. How often to 25.4 handlebars break or bend when their 31.8 counterparts would have survived?

For road bikes, the larger radius can add comfort. For XC and AM riders, there is no real benefit.


wrong

You have failed to answer how often 25.4 handle bars bend or break in situations when 31.8's would not.

Additionally no benefit for XC or AM riders was shown by your eloquent post.

Thomson (http://www.lhthomson.com/stems.htm)

I know i know, I ride their damn trail.... at their factory.

I must of got happy fingers, and hit the P.

Have had two carbon bars, neither of which failed. An older IRD Mosaic. Nice bend/sweep, sold the bike it was on, a rigid XC hardtail. Recently tried Titec carbon riser. Snap, crackle, pop noises greeted me from the very first.

Double checked that it wasn't overtorqued, checked for cracks and so on. No grease. No overtightening of the levers/grips/shifters. Had a local shop take a look as well, just to be sure I wasn't missing something. Nothing was slipping/moving that I could find, either. Maybe it's fine, but the noise annoyed and worried me enough that I found myself not trusting the damn bar. I hate that. It impinges on riding joy. No cracks or anything found upon removal.

Maybe it's only making nose, but it annoyed the hell out of me. Swapped back to an alu bar: Sunline V-1 OS. Great feel, bend, and sweep. Looooooove the width. It's quiet. I"m much happier, and don't give a rats ass that it's slightly more weight.

Typically 31.8's are a little heavier.

http://i16.photobucket.com/albums/b23/konarider24/Bikeforums%20Stuff/stairway_fail.jpg

My 31.8 gravity carbons are very light compared to what I used when I had 25.4, and trust them alot more.

I trust them, I don't go any easier on them than I do on aluminum bars. Just check em' every now and then for cracks

http://i16.photobucket.com/albums/b23/konarider24/Bikeforums%20Stuff/stairway_fail.jpg

My 31.8 gravity carbons are very light compared to what I used when I had 25.4, and trust them alot more.

http://www.eastonbike.com/PRODUCTS/BARS/bar__top.html
http://www.raceface.com/components/handlebars/
http://mtb.fullspeedahead.com/fly.aspx?layout=product&taxid=141

When you compare any of the above manufacturers, the 31.8 version is always heavier than the 25.4.

So when I say, "Typically 31.8's are a little heavier.", I am correct.

Sorry, no stairway to fail. :(

I used a carbon Scott LFX (120 grams) straight bar on my hardtail for 8 years or so, no problems of any sort. I still have that bar and would use it again with no hesitation. My current hardtail has a straight FSA carbon and my FS has a Raceface carbon. I trust these bars.

A lot of people seem to fear catastrophic breakage of carbon bars, as if any little nick or scrape will propagate into full blown failure. I have yet to speak with ANYONE who has experienced this. CF does not snap off, as far as I know. While it can indeed fail, like in a crash, the fibers and resin still somewhat hold things together in a mushy kind of way. I know this from experience because I've ridden out of the woods with a mushy bar.

Now, aluminum is a material with a potential for catastrophic failure, gouges, scratches and stress risers being the causes and precursors to breakage. Many people who ride hard will replace aluminum bars every two years or even yearly depending. Aluminum indeed has a limited fatigue life (cycles to failure). Carbon fiber is known for it's very high/extended fatigue life. There must be something good about it if The Boeing Company is building it's Dreamliner out of the stuff.

Edit: To the OP, I probably would not trust CF bars INDEFINITELY, but, geez, I would for quite a while, barring any bad crashes.

http://www.eastonbike.com/PRODUCTS/BARS/bar__top.html
http://www.raceface.com/components/handlebars/
http://mtb.fullspeedahead.com/fly.aspx?layout=product&taxid=141

When you compare any of the above manufacturers, the 31.8 version is always heavier than the 25.4.

So when I say, "Typically 31.8's are a little heavier.", I am correct.

Sorry, no stairway to fail. :(

Yes a whole lot of fail for you due to your failing to recognize the fact that 25.4 bars are really flexy, which is one reason why companies started to go 31.8. A 31.8 allows more contact surface area which provides a stiffer bar, handlebar combination. I was also referring to 31.8 DH bars, where there is weight savings by going with a carbon bar.

Yes a whole lot of fail for you due to your failing to recognize the fact that 25.4 bars are really flexy, which is one reason why companies started to go 31.8. A 31.8 allows more contact surface area which provides a stiffer bar, handlebar combination. I was also referring to 31.8 DH bars, where there is weight savings by going with a carbon bar.

No, 25.4 are not "really flexy". 31.8 might be stronger, but 25.4 are not "really flexy" and are more than strong enough for XC and AM use.

BTW, Your cutesy "stairway to fail" originally responded to me saying that 31.8's are a little heavier than 25.4's (which is still true).

If you were stating that your 31.8 carbons are lighter than your old 25.4 AL that is fine, but comparing the weight of AL to CF is not exactly apples to apples.

Con mucho gusto.

How can you remotely make a statement that 25.4 isn't flexy when you have a smaller diameter bar, which will flex alot more than a larger diameter bar will, denying that is pure stupidity. Having a really light weight handlebar really shouldn't be a major decision. Specialized, Trek, Fisher, etc make some light bikes that have the oversized stuff on there, where do you find the 25.4 stuff now, on the lower end models as all of the high end offerings now have oversized bars on them. Handlebars shouldn't be scary light to begin with, there's actually alot of forces on the bars when riding, 25.4 flexes, 31.8 flexes to a point.

I also swap my bars around once in awhile for a higher rise aluminum bar every once in awhile for the heck of it, and even at 31.8 can feel the bars flex, so I can't possibly see how a 25.4 bar won't flex, it will only flex more.

Edit, I'm done with arguing about this. Just isn't worth my time with someone who probably never rode a 31.8 handlebar.

I ride 25.4 bars. I'm 145lbs though. Don't really feel them flex, but they might be.

How can you remotely make a statement that 25.4 isn't flexy when you have a smaller diameter bar, which will flex alot more than a larger diameter bar will, denying that is pure stupidity. Having a really light weight handlebar really shouldn't be a major decision. Specialized, Trek, Fisher, etc make some light bikes that have the oversized stuff on there, where do you find the 25.4 stuff now, on the lower end models as all of the high end offerings now have oversized bars on them. Handlebars shouldn't be scary light to begin with, there's actually alot of forces on the bars when riding, 25.4 flexes, 31.8 flexes to a point.

I also swap my bars around once in awhile for a higher rise aluminum bar every once in awhile for the heck of it, and even at 31.8 can feel the bars flex, so I can't possibly see how a 25.4 bar won't flex, it will only flex more.

Edit, I'm done with arguing about this. Just isn't worth my time with someone who probably never rode a 31.8 handlebar.

Here is a recap:
1. 25.4 is more than strong enough for XC and AM use.
2. You said 25.4 is "very flexy". Not true. It takes over 100 lbs to flex it millimeters. Of course 31.8 will flex less, but in the real world this in negligible.

BTW, I do have 31.8 and 25.4 Easton bars on Thomson stems on 2 of my MTB's. I also weigh over 225 lbs in riding gear and don't count grams on my bikes.

What makes an All Mountain ride for you?

I can see 25.4 being just fine for xc and light am use, but on more aggressive AM that is borderline FR/DH, I'd want a 31.8.

What makes an All Mountain ride for you?

I can see 25.4 being just fine for xc and light am use, but on more aggressive AM that is borderline FR/DH, I'd want a 31.8.

My definition of AM is anything more challenging than XC involving steep rocky & rooty descents where you need disc brakes to slow you down. Once you are on terrain where the added stopping power of discs becomes critical you are riding AM.

I agree that 31.8's are better suited for challenging AM approaching FR/DH. Especially if you regularly hit a lot of jumps or drop offs.

Regardless of whether or not I think 31.8 is overkill for most bikes, it is becoming the new standard for high end bikes and many years from now 25.4 stems might be a retro novelty.

Ditto, there is no such thing :)

Damn, son, how'd you get all them stars?