Carbon bar indentations

[Matthew]

Adjusted my Deda carbon bars today and noticed the stem clamp has made indentations on the bar clamping area by the top two stem bolts. Bolts under the bar have not left any marks. No clearcoat bubbling, no loose fibers no cracks. Safe to ride? Checked some used ones on ebay and they seem to have similar looking marks as mine. Am I being paranoid? Seen this before on your carbon bars? Believe they have been there a while and I have a little over 2000 miles on them. Superleggera model with 31.7 clamp diameter. I did not use a torque wrench but tried to be gentle. I know, I am an idiot. Thanks for any input. Matt. Sorry if this has been covered already and sorry I didn't post pics.

[Louis]

I don't have any CF bars myself, but I imagine that this happened because the epoxy can creep over time, leaving you with permanent deformation.

The carbon fibers themselves are most likely fine, and I wouldn't worry about it, if that happened to me.

[Matthew]

Forgot to mention too that the bar clamp area is smooth. Does not have that textured area some bars have.

[stephenmarklay]

I have grown leary of CF for all the good there is that bad part that drives me away.

I hate to say that I heard a podcast today and they were talking about a guy who’s CF bar broke, his hand went into the spokes, he road off a bridge and died.

Sorry.

[Louis]

I hate to say that I heard a podcast today and they were talking about a guy who’s CF bar broke, his hand went into the spokes, he road off a bridge and died.

Sorry.

This is a joke, right?

If not, without more details to know what really happened, it's baseless fear mongering.

[madsciencenow]

I recently took a carbon bar off my bike and it was completely cracked where the stem bar junction was. I'm pretty sure I didn't put the bar on so I'm not sure if a torque wrench was used or not but it certainly is a good example of how soft carbon is and why s torque wrench is a good idea.https://uploads.tapatalk-cdn.com/20170317/d2e17f64039a413bee19c8eaea5f471e.jpg


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[CAAD]

They really must have cranked that thing down. I had a bar where you could see a impression of the clamp, was fine for years. Ended up retiring them to go with a narrower bar. I have been running alloy bars for a couple years now. I just made the switch back to carbon bars, kept sweating through alloy ones.

[Tickdoc]

I have a beautiful 3t ergonova bar that was replaced with aluminum on my cervelo because it was crimped and deemed unsafe to ride by my mechanic during a stem swap.

It looks fine to me, but I trust his judgement.

[cmbicycles]

I think most bars will develop an indentation from the clamp, as the carbon/resin is softer than the metal. I have a set of bars (3T Ergosum) that have indents at the edges of where the bar was clamped but no cracking. It makes me nervous but shows no other signs... yet, I bought them used on the forum last year +/- and still haven't gotten to put them on a bike.

[stephenmarklay]

This is a joke, right?

If not, without more details to know what really happened, it's baseless fear mongering.

This is not a joke. It was talked about on the most recent Trainer Road podcast.

[peanutgallery]

Just because you spent a lot of money on an expensive part does not mean it isn't a consumable. Inspect periodically and be prepared to replace when necessary. Not unlike a chain, tire, cable and so on. A new carbon bar (properly installed and torqued) is way cheaper than a trip to the dentist for a mouthful of implants

If there's any doubt in your mind, and I'm assuming there is since you're asking for opinions, replace it

[R3awak3n]

This is not a joke. It was talked about on the most recent Trainer Road podcast.

ok fine but who knows about how well that bike was maintained, if the bars were torqued properly or if there was any other reason why the bars broke. Lets be honest, he could have had something else break and fall of the bridge.

[madsciencenow]

I think most bars will develop an indentation from the clamp, as the carbon/resin is softer than the metal. I have a set of bars (3T Ergosum) that have indents at the edges of where the bar was clamped but no cracking. It makes me nervous but shows no other signs... yet, I bought them used on the forum last year +/- and still haven't gotten to put them on a bike.



I think it would have been quite a long time until mine completely snapped and agree with peanutgallery that inspection is a good idea.


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[Pastashop]

3T Handlebar - Stem Clamp Damage Cut up and review:
https://www.youtube.com/watch?v=HZwhHRazjK8

Lightweight aluminum bars aren't going to be completely trouble free and need to be replaced periodically also, but you can usually judge an impending failure by the bars developing a slight bend / droop across the nominally flat portion ("flats"). They should not be bent back, as that accelerates failure.

http://yarchive.net/bike/handlebar_break.html

[notsew]

I'd get a screwdriver or something and tap tap tap along the bar. If it sounds flatter around the crimped part, you probably have some delamination and it is trash. If not, I'd probably ride it.

[bitpuddle]

This is why I don't ride carbon bars. It is too easy to damage them and failure is catastrophic. I'm not even terribly happy about carbon steerers, but that is harder to avoid.

If there is any question about a car in part, replace it.

[zap]

This is why I don't ride carbon bars. It is too easy to damage them and failure is catastrophic. I'm not even terribly happy about carbon steerers, but that is harder to avoid.

If there is any question about a car in part, replace it.

Aluminum bars can fail suddenly as well.

As noted in earlier posts, inspect critical components on your bike periodically.

[stephenmarklay]

ok fine but who knows about how well that bike was maintained, if the bars were torqued properly or if there was any other reason why the bars broke. Lets be honest, he could have had something else break and fall of the bridge.


Absolutely, on every account. That is why I said sorry just for mentioning it.

Having said that I don’t think carbon bars, forks and stems should be casually observed.

It would be cool of more and cheaper X-ray type services were around.

[Matthew]

I did a little more inspecting and I am comfortable riding them for now. Took a pic of the area affected and will monitor closely for any changes. That being said I did go out yesterday and by a new aluminum bar just in case!!

[Macadamia]

It would be cool of more and cheaper X-ray type services were around.

I'll check Harbor Freight next time I'm there