If you are considering carbon clinchers you need to watch this...

pilot_pete

The 'which' carbon clincher question comes up time and again on these forums. Carbon clinchers with rim brakes have a significant failure rate but the advocates always try to defend them and state it is incorrect braking technique etc etc.

Well, if you are considering them for your bike, do yourself a favour and watch this video (first of two parts) by a leading composites expert who has worked for the likes of Boeing and has extensive experience in composite design, manufacturing and quality control. He has also designed and made carbon composite parts for the Aussie cycling team and repairs carbon bikes and parts for a living.

https://youtu.be/ET1jRVynOBA

You can't get much more definitive than him stating that carbon clinchers are not fit for descending where significant braking is required. He states temperatures of 250 degrees Celsius plus are easily generated during descents and the tg of the majority of resins is about 180 degrees Celsius. He says Zipp displayed the best resistance to brake track damage along with Lightweight but said their 'special' resins which could resist higher temperatures were more brittle (he said it is a trade off).

He says that carbon clinchers with disc brakes are the industries' admission that they got it wrong when carbon rims with rim brakes were introduced. This has been my opinion since I had a set delaminate a few years ago.

PP

jacksoneaker

Hey

cycleclinic

not again. please not again.

964cup

Get tubs. Lighter weight, better ride, no brake problems.

MiddleRinger

I don't brake so it's all good....

ugo.santalucia

Pilot Pete wrote:

This has been my opinion since I had a set delaminate a few years ago.

PP

You should link to the thread, as the story, if I remember correctly, is a bit more complicated than that and I remember a row with Derek of Wheelsmith. Is it fair to say that you first crashed and possibly damaged the rim and then claimed that it delaminated under braking?

ugo.santalucia

ugo.santalucia wrote:

Pilot Pete wrote:

This has been my opinion since I had a set delaminate a few years ago.

PP

You should link to the thread, as the story, if I remember correctly, is a bit more complicated than that and I remember a row with Derek of Wheelsmith. Is it fair to say that you first crashed and possibly damaged the rim and then claimed that it delaminated under braking?

EDIT: found it

viewtopic.php?f=40013&t=12880277&hilit=wheelsmith

joe2008

thecycleclinic wrote:

not again. please not again.

Well worth watching before dismissing, great videos, Raoul Luescher really knows his stuff.

Glad my carbon rims are tubular, and my clinchers are aluminium.

matt_n-2

I've seen the video before, it's a good insight.

I'd only consider tubs really.

thegreatdivide

Pilot Pete wrote:

The 'which' carbon clincher question comes up time and again on these forums. Carbon clinchers with rim brakes have a significant fai.......blah blah blah...blah blah blah...blah blah blah blah blah.

PP

flasher

viewtopic.php?f=40013&t=13068627&p#p19938863

pilot_pete

ugo.santalucia wrote:

ugo.santalucia wrote:

Pilot Pete wrote:

This has been my opinion since I had a set delaminate a few years ago.

PP

You should link to the thread, as the story, if I remember correctly, is a bit more complicated than that and I remember a row with Derek of Wheelsmith. Is it fair to say that you first crashed and possibly damaged the rim and then claimed that it delaminated under braking?

EDIT: found it

viewtopic.php?f=40013&t=12880277&hilit=wheelsmith

That's not the only pair of wheels that this has happened to though, it also happened to the replacement rims, which had no impacts at all, and fyi there was no crash, it was a massive pothole and the rims were incredibly strong and took the impact with no damage, the future damage was caused by heat, but let's no go there - you can discount my first experience if you want to say it was down to impact damage, I really don't mind because this thread is not about my sole experience, it is about the huge number of carbon rims that have suffered heat damage, which the industry acknowledges is a problem... :roll:

PP

pilot_pete

thecycleclinic wrote:

not again. please not again.

No need for you to participate.

The thread is aimed at people with no experience of carbon rims who may like to watch the video which is made by a highly qualified carbon fibre expert who describes the problems which the industry knows these rims suffer from, who has done extensive testing, deemed them so unsuitable for rim braking in hills that he wouldn't go near them, so they can view and come to their own conclusions based on expert opinion rather than the opinion of those who have a vested interest in making money from selling them...

Before you part with your hard earned, ensure you know if the product you are contemplating buying is fit for purpose.

PP

ugo.santalucia

Pilot Pete wrote:

ugo.santalucia wrote:

ugo.santalucia wrote:

Pilot Pete wrote:

This has been my opinion since I had a set delaminate a few years ago.

PP

You should link to the thread, as the story, if I remember correctly, is a bit more complicated than that and I remember a row with Derek of Wheelsmith. Is it fair to say that you first crashed and possibly damaged the rim and then claimed that it delaminated under braking?

EDIT: found it

viewtopic.php?f=40013&t=12880277&hilit=wheelsmith

That's not the only pair of wheels that this has happened to though, it also happened to the replacement rims, which had no impacts at all, and fyi there was no crash, it was a massive pothole and the rims were incredibly strong and took the impact with no damage, the future damage was caused by heat, but let's no go there - you can discount my first experience if you want to say it was down to impact damage, I really don't mind because this thread is not about my sole experience, it is about the huge number of carbon rims that have suffered heat damage, which the industry acknowledges is a problem... :roll:

PP

I might even agree with you but in the interest of fairness it is good to know the all story, given you shared it at the time.... So th replacement rim also delaminated?

sloppyschleckonds

Pilot Pete wrote:

thecycleclinic wrote:

not again. please not again.

No need for you to participate.


PP

Think I'd rather listen to Malcolm than you

SS

pilot_pete

SloppySchleckonds wrote:

Pilot Pete wrote:

thecycleclinic wrote:

not again. please not again.

No need for you to participate.


PP

Think I'd rather listen to Malcolm than you

SS

Fair enough, I won't stop you. And by the way, I wasn't asking you to listen to me, I was posting a video link to a respected industry professional with years of carbon fibre experience and no vested interest. Just remind me, Malcolm is also independent and doesn't sell carbon clincher rims does he? Oh no, thought not...

PP

pilot_pete

ugo.santalucia wrote:

I might even agree with you but in the interest of fairness it is good to know the all story, given you shared it at the time.... So th replacement rim also delaminated?

Yep, overheated brake track. Didn't so much delaminate, but the resin softened, the rim bulged and then the resin re-hardened. Rim goosed.

PP

mamba80

Pilot Pete wrote:

ugo.santalucia wrote:

I might even agree with you but in the interest of fairness it is good to know the all story, given you shared it at the time.... So th replacement rim also delaminated?

Yep, overheated brake track. Didn't so much delaminate, but the resin softened, the rim bulged and then the resin re-hardened. Rim goosed.

PP

you dont know how to ride then, plenty of people use CC in the alps, on training camps and in races, with zero issues.
Giant and Spesh, 2 USA companies, would nt spec as std CC unless they were sure they were safe, fwiw, you were using swissstop yellows? they are a terrible pad.

pilot_pete

mamba80 wrote:

Pilot Pete wrote:

ugo.santalucia wrote:

I might even agree with you but in the interest of fairness it is good to know the all story, given you shared it at the time.... So th replacement rim also delaminated?

Yep, overheated brake track. Didn't so much delaminate, but the resin softened, the rim bulged and then the resin re-hardened. Rim goosed.

PP

you dont know how to ride then, plenty of people use CC in the alps, on training camps and in races, with zero issues.
Giant and Spesh, 2 USA companies, would nt spec as std CC unless they were sure they were safe, fwiw, you were using swissstop yellows? they are a terrible pad.

Don't go there. You have no idea. Every single cooked rim in your opinion is down to incorrect braking technique. That was the industry response to the problem too. Even if I couldn't brake correctly (which I can, and indeed teach it) the fact is that constant braking down a long descent is a foreseable incorrect technique that less skillful riders may incorrectly adopt. Therefore the product should be designed to be able to handle this or it should be sold with a warning.

Stop arguing with me as it is fruitless. The fact is carbon clinchers can overheat when braking whilst descending. Look at the video and comment about that and the expert in it. Saying that companies wouldn't spec things unless they were completely safe, blah blah blah is guff. Samsung Galaxy Note anyone?

PP

Oh and p.s. I know plenty of people who bought those phones and they haven't burst into flames. Doesn't make them safe though does it. :roll:

mamba80

Samsung had to withdraw their product as it was clearly unsafe.

not the case with SLR 0/1's CC and Roval CC from giant and Spesh respectively.

lets face it, if you cant do it, teach it ! lol!

pilot_pete

mamba80 wrote:

Samsung had to withdraw their product as it was clearly unsafe.

not the case with SLR 0/1's CC and Roval CC from giant and Spesh respectively.

lets face it, if you cant do it, teach it ! lol!

Are you going to comment about the video and the industry expert and put forward a reasoned argument to defend what you see as no issue, or just keep giving anecdotal evidence and making snide comments? No thought not. :roll:

PP

mfin

The video has been posted plenty of times on here PP, most people commenting here know all the issues of carbon clinchers full well. It's hardly complex to understand the issues.

You've basically either got bad braking technique / are a bit chunky / have been using them on descents that are a bit beyond what they are suited for / you're just not that confident a descender are using too much braking still... or some combination of these things, it's quite simple. Following that you've cocked your rims up and now you want to sound like you're helping educate people, it's quite funny as well as a bit boring.

Did you buy them for racing and any potential aero advantage anyway? Probably not, probably cos you liked the look of deep sections if you're like most people who buy them.

There's no point getting shirty with the responses really, your attempt at an educational thread is just a repeat of what's been done plenty of times on here, even including the same video. Of course, perhaps you just felt it all needed repeating yet again.

Have a beer and chill out.

pilot_pete

And another one claiming they know about me and why my wheels were cooked.... :roll: The only possible reason you left out is the one in the video; that they cannot handle the heat generated when descending. :roll:

You going to comment on the video then? Prove Raoul wrong? No, thought not. :roll:

PP

P.s. This beer is going down nice.

mfin

There is no heat generated in descending itself, only braking, and you were braking too much for what that particular rim could take with regards heat. It's quite glaringly simple mickey mouse stuff.

Other people might brake less on the same hills, being better and faster at descending, not needing to brake as hard as they are lighter people maybe. Hence with way less heat build up the exact same rim could be absolutely fine on the same roads for someone else.

Most people know there are limits because of the design of carbon clinchers to do with heat dissipation, it's all pretty obvious stuff.

BTW I've seen the video when it was first posted about on forums, and the topics in it are not 'news' at all, don't understand what there is to comment on about it really.

pilot_pete

mfin wrote:

There is no heat generated in descending itself, only braking, and you were braking too much for what that particular rim could take with regards heat. It's quite glaringly simple mickey mouse stuff.

Other people might brake less on the same hills, being better and faster at descending, not needing to brake as hard as they are lighter people maybe. Hence with way less heat build up the exact same rim could be absolutely fine on the same roads for someone else.

Most people know there are limits because of the design of carbon clinchers to do with heat dissipation, it's all pretty obvious stuff.

BTW I've seen the video when it was first posted about on forums, and the topics in it are not 'news' at all, don't understand what there is to comment on about it really.

Ok, I'll bite.

There is no heat generated in descending itself, only braking

good start, I am impressed.

you were braking too much for what that particular rim could take with regards heat

genius, you actually get it don't you? The rim was not up to the braking force applied to it and could not withstand the heat generated. I should just rest my case here...

Other people might brake less on the same hills

yes, and some (many) WILL brake more. I descend extremely fast. Using correct braking technique letting the bike run, braking hard before the bend, releasing the brakes and taking the corner using the apex and letting the bike run to the next bend. Explain where the braking technique is wrong if you can.

not needing to brake as hard as they are lighter people maybe.

yeah, and others are heavier. I'm not heavy and the wheels I have used were rated for riders up to 100kg, I'm closer to 75kg. So well within the stated weight limit, yet the rims couldn't handle the heat generated.

Hence with way less heat build up the exact same rim could be absolutely fine on the same roads for someone else.

but unfortunately all your assumptions were incorrect so this statement is meaningless.

Most people know there are limits because of the design of carbon clinchers to do with heat dissipation

oh yeah? How very magnanimous of you. Think about those who don't know who might actually gain some knowledge from learning about the limitations of these products. It seems many others who 'know' seem to just defend and use the industry line that it is all 'user error'. You have admitted that the products are not fit for purpose by your attempts at explaining why my rims failed. :roll:

the topics in it are not 'news' at all, don't understand what there is to comment on about it really.

News? Nothing has been posted about anything being news. It is a link to a video (that some have seen before), posted in Road Buying Advice that some people contemplating buying carbon clinchers might find useful in gaining some knowledge about the limitations of these products and garnering the views of an industry expert who holds the opinion that they are not fit for purpose. If you don't want to comment on that then fine. Problem is you just want to have a dig rather than either agree with the expert opinion or post something useful and factual (rather than your guess work and assumption about my particular rim failure case) that puts the counter argument. But you can't can you? So what are you trying to achieve?

So far, nobody has put a counter argument backed up with any kind of facts other than 'I know many riders who have descended the Alps, raced, blah, blah, blah with no problems'. I know many too, but also have a number of mates on various branded rims who have suffered the same failures due to heat and they all know how to descend.... Anecdotal evidence isn't evidence.

PP

Midlands Grimpeur

Anecdotal evidence isn't evidence.

I am not trying to start an argument but to be fair, if you want to get into semantics, your evidence is anecdotal as by definition anecdotal evidence is based on personal testimony. You haven't provided any hard facts backed up by something concrete like say an engineers report into the structural failure of your wheels. In essence you have just told us that you had two pairs of rims which both delaminated, just as someone who has said there wheels were fine, we are all giving anecdotal evidence.

mamba80

Pilot Pete wrote:

mamba80 wrote:

Samsung had to withdraw their product as it was clearly unsafe.

not the case with SLR 0/1's CC and Roval CC from giant and Spesh respectively.

lets face it, if you cant do it, teach it ! lol!

Are you going to comment about the video and the industry expert and put forward a reasoned argument to defend what you see as no issue, or just keep giving anecdotal evidence and making snide comments? No thought not. :roll:

PP

as i hinted at, 'yellows are an old design of pad, newer pads dissipate heat better.

i am always wary of people who say they are open minded, generous, sensitive or "descend extremely fast" the fact they need to say these things about themselves is rather worrying and usually hides some insecurity about their really abilities.

the USA is a litigious country, and as i ve said, you ve failed to acknowledge, 2 major manufacturers spec CC on their mid range racing cycles c/w rim brakes and america has plenty of hills and in places is also very hot, yet a google of their wheels and problems show up a few broken spokes....... they must have sold 1000's of these bikes all over the world and the internet is not awash with delamination stories.

as for the vid, it is his opinion, it isnt every industry experts one.

you ve a beef about CC based on your experiences, thats it, other people have different opinions based on their experiences and they arent starting new threads posting videos on the benefits of carbon wheels.

napoleond

Being well aware of this video I still went for carbon clinchers last year for Triathlon. They've been brilliant wheels.
Knowing the heat issues I make the informed decision not to use them on a ride with a lot of fast descending as I'm not the most confident descender after a bad crash 7 years ago, as I know I ride the brakes too much. If I was much more confident I'd consider them.

pilot_pete

Midlands Grimpeur wrote:

Anecdotal evidence isn't evidence.

I am not trying to start an argument but to be fair, if you want to get into semantics, your evidence is anecdotal as by definition anecdotal evidence is based on personal testimony. You haven't provided any hard facts backed up by something concrete like say an engineers report into the structural failure of your wheels. In essence you have just told us that you had two pairs of rims which both delaminated, just as someone who has said there wheels were fine, we are all giving anecdotal evidence.

Sorry, I wasn't producing my experience as evidence, I was answering the posts about my experience.

I was linking to the video where the expert was giving his opinion based upon his evidence - hundreds of tests and reports on failed rims for clients. The whole point was to try to get some debate going about the expert's opinion, but of course nobody has offered any independent evidence to counter it as it is easier to just pick apart my anecdotal evidence! Raoul is the expert who produces the 'engineers reports' about failed carbon parts. Care to comment about him?

PP

pilot_pete

mamba80 wrote:

Pilot Pete wrote:

mamba80 wrote:

Samsung had to withdraw their product as it was clearly unsafe.

not the case with SLR 0/1's CC and Roval CC from giant and Spesh respectively.

lets face it, if you cant do it, teach it ! lol!

Are you going to comment about the video and the industry expert and put forward a reasoned argument to defend what you see as no issue, or just keep giving anecdotal evidence and making snide comments? No thought not. :roll:

PP

as i hinted at, 'yellows are an old design of pad, newer pads dissipate heat better.

i am always wary of people who say they are open minded, generous, sensitive or "descend extremely fast" the fact they need to say these things about themselves is rather worrying and usually hides some insecurity about their really abilities.

the USA is a litigious country, and as i ve said, you ve failed to acknowledge, 2 major manufacturers spec CC on their mid range racing cycles c/w rim brakes and america has plenty of hills and in places is also very hot, yet a google of their wheels and problems show up a few broken spokes....... they must have sold 1000's of these bikes all over the world and the internet is not awash with delamination stories.

as for the vid, it is his opinion, it isnt every industry experts one.

you ve a beef about CC based on your experiences, thats it, other people have different opinions based on their experiences and they arent starting new threads posting videos on the benefits of carbon wheels.

I can't comment about the wheels you have mentioned as I know nothing about them. In the video Raoul states that he has seen carbon rim failures of all the brands from cheap imports through to major brands. I have seen personally failures of imported rims (the ones mine were built with plus another guys), Zipp, and Renolds Assaults.

My rim failures were a few years ago now and the Swisstop Yellows weren't such an old design then. The supplied cork pads did not stop the bike at all, dry or wet. They just burnt and smelt and were totally inadequate. But let's not get into a debate about me and my wheels, lets hear some debate about the video.

I agree the video is Raoul's opinion. You can't just discount it as it is not 'every experts one'. Where is one expert giving the counter argument? Why not post a link to their work? Make sure they are independent though and not making/ selling wheels.

PP

mfin

Pilot Pete wrote:

mfin wrote:

There is no heat generated in descending itself, only braking, and you were braking too much for what that particular rim could take with regards heat. It's quite glaringly simple mickey mouse stuff.

Other people might brake less on the same hills, being better and faster at descending, not needing to brake as hard as they are lighter people maybe. Hence with way less heat build up the exact same rim could be absolutely fine on the same roads for someone else.

Most people know there are limits because of the design of carbon clinchers to do with heat dissipation, it's all pretty obvious stuff.

BTW I've seen the video when it was first posted about on forums, and the topics in it are not 'news' at all, don't understand what there is to comment on about it really.

Ok, I'll bite.

There is no heat generated in descending itself, only braking

good start, I am impressed.

you were braking too much for what that particular rim could take with regards heat

genius, you actually get it don't you? The rim was not up to the braking force applied to it and could not withstand the heat generated. I should just rest my case here...

Other people might brake less on the same hills

yes, and some (many) WILL brake more. I descend extremely fast. Using correct braking technique letting the bike run, braking hard before the bend, releasing the brakes and taking the corner using the apex and letting the bike run to the next bend. Explain where the braking technique is wrong if you can.

not needing to brake as hard as they are lighter people maybe.

yeah, and others are heavier. I'm not heavy and the wheels I have used were rated for riders up to 100kg, I'm closer to 75kg. So well within the stated weight limit, yet the rims couldn't handle the heat generated.

Hence with way less heat build up the exact same rim could be absolutely fine on the same roads for someone else.

but unfortunately all your assumptions were incorrect so this statement is meaningless.

Most people know there are limits because of the design of carbon clinchers to do with heat dissipation

oh yeah? How very magnanimous of you. Think about those who don't know who might actually gain some knowledge from learning about the limitations of these products. It seems many others who 'know' seem to just defend and use the industry line that it is all 'user error'. You have admitted that the products are not fit for purpose by your attempts at explaining why my rims failed. :roll:

the topics in it are not 'news' at all, don't understand what there is to comment on about it really.

News? Nothing has been posted about anything being news. It is a link to a video (that some have seen before), posted in Road Buying Advice that some people contemplating buying carbon clinchers might find useful in gaining some knowledge about the limitations of these products and garnering the views of an industry expert who holds the opinion that they are not fit for purpose. If you don't want to comment on that then fine. Problem is you just want to have a dig rather than either agree with the expert opinion or post something useful and factual (rather than your guess work and assumption about my particular rim failure case) that puts the counter argument. But you can't can you? So what are you trying to achieve?

So far, nobody has put a counter argument backed up with any kind of facts other than 'I know many riders who have descended the Alps, raced, blah, blah, blah with no problems'. I know many too, but also have a number of mates on various branded rims who have suffered the same failures due to heat and they all know how to descend.... Anecdotal evidence isn't evidence.

PP

Are you sure you didn't bore the wheels to death?

Sounds to me like you're more likely a completely average descender who has had to learn and think about how to descend by the way you come out with your description of it. Nothing wrong with not being a natural at something.

Look at what NapD said, he's using them for environments which will not present problems as he is aware of the limits of the design. It's all common sense really.

Just steer clear of carbon clinchers yourself, job done.

As said, the video has been posted a good few times before and I suppose if a few new watchers find the video interesting then all good. I can't for the life of me see what your analysis of the video or your personal experience adds for anyone really, there's nothing new and it doesn't help that it's all very dull and square too (this is why people are responding how they are).