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View Full Version : the sky is falling: carbon steerers


eddief
06-17-2010, 10:50 PM
oh crap, is Grant Peterson the oracle? I'm sorta joking, but this is sorta interesting re: carbon steerers:
http://velonews.competitor.com/2010/06/news/steered-wrong-racers-concerned-about-broken-carbon-steerer-tubes_121389?utm_source=twitterfeed&utm_medium=twitter

retrogrouchy
06-17-2010, 11:25 PM
oh crap, is Grant Peterson the oracle? I'm sorta joking, but this is sorta interesting re: carbon steerers:
http://velonews.competitor.com/2010/06/news/steered-wrong-racers-concerned-about-broken-carbon-steerer-tubes_121389?utm_source=twitterfeed&utm_medium=twitter

Nah, he says all the blades are going to fail.... ;)

That said, you couldn't pay me enough Monet to use plastic in my steerer or anywhere else in my fork. :D

fogrider
06-18-2010, 12:07 AM
this is bs. over tighten and the carbon crushes not shear off somewhere below. and it seems that mechanics only over torque stems on treks. come on trek, man up!

rcnute
06-18-2010, 12:19 AM
I don't even know what a torque wrench looks like.

johnnymossville
06-18-2010, 09:10 AM
That doesn't look like an overtightening issue to me.

I've raced with the guys involved. Pretty good riders.

rounder
06-18-2010, 10:56 AM
I saw the Trek up close at BikeJam in Baltimore. It looked like a clean break of the steerer, rather than a crack. There was also something that looked like carbon cloth sticking out of the stem, but am not sure where that came from. The race had just started and the rider hadn't even gone a 100' before it failed. The announcer said that it was the second Trek with a failed steerer that he had seen in the past two days.

Avispa
06-18-2010, 06:39 PM
Didn't Georgie fell on his arse at Paris Roubaix because of this too?

..A..

Charles M
06-18-2010, 06:41 PM
Hincapie had a metal steer tube...

Tim
06-19-2010, 05:04 PM
Yes- but a Trek bike.

dvs cycles
06-19-2010, 06:02 PM
Hincapie had a metal steer tube...And he had crashed earlier in the day too. The steerer was aluminum.

Russity
06-19-2010, 06:10 PM
I work for a Trek dealer as a mechanic, have done for years. In six years of selling the old style Madones, we only had TWO come back for warranty and both were instances where the drop outs needed re-fixing.

In three years of selling the new Madones, we have warrantied upwards of eight seperate customers bikes. One poor guy is onto his fourth warranty frame, I kid you not!!! All these warranties have been through carbon cracks in the frames.

To their credit, Trek have always replaced the frames, but the customers are rightfully losing confidence in their bikes.

We also sell Colnagos and in eight years of trading those, we have had one warranty and that was for a cracked (aluminium) drop out. And the difference here, in our oppinion, is that Colnago have used a tried and tested build method from the start and don't go for radical design changes when they know their bikes are strong and will last.

I love Trek bikes and applaud what the company has done for cycling over the past ten years, but it pains me to see them build bikes that just aren't good enough.

If it aint broken.....don't try and fix it!

Fivethumbs
06-20-2010, 03:35 AM
I think it's ridiculous when you have a list of must do's like Trek issued in their statement. A steerer should not break unless it's been totally abused - like putting a huge stack of spacers or totally cranking down on the stem bolts or a crash. They're essentially saying, "Well, you used a FSA stem and didn't put a spacer on top, therefore, it's all your fault." Whata joke.

rustychain
06-20-2010, 05:57 AM
Under the title of I just don't know,
I had a carbon steerer tube fail. JRA and I am holding the bars in my hand with only the cables attached to the bike. I was going uphill so the speed was slow and I was able to avoid crashing. A nick clean break just above the headset on an Easton fork. No crashes and properly torqued I was told that it may have resulted in the stem being all the way down, IE no spacers. With no place for the stem to flex it concentrated the stress at that point. Like I said, I just don't know :confused:
FYI I have been on full carbon forks for a few years after this issue and have had several bad crashes but without and fork/ steerer tube damage (knock on wood)
I am a bit sceptical of the article as details are short. I have never owned a Trek nor do I wish (to mass market for me) to but over the years they have had a fairly good reputation.

weaponsgrade
06-20-2010, 01:35 PM
Trek needs to see what Raleigh's doing:
http://www.youtube.com/watch?v=5z1fSpZNXhU

11.4
06-20-2010, 08:00 PM
A local shop was building up a 13 lb Madone and the mechanic handed me the fork. I could pinch the steer with my fingers. And I was skeptical when I could do that to the top tube on a Madone a couple years ago. It's not a bike I'd buy. There's a lot of weight to save in a fork, but a lot of risk if you don't do it right. A Trek Madone has been, to me, an example of a BP oil rig -- insufficient margin for error. Proper installation is one thing. Fastidious perfection using some standards that other fork manufacturers and framebuilders don't demand is a bit much. I want to slide in a race, pick up the bike, and race away again. I don't want to have to quit and send it to Trek for preventive replacement. Doesn't it say something if we are having this discussion about a particular brand? Someone want to start a thread accumulating broken forks on Serottas? Or Sachs? Or Parlees? Or Colnagos? Trek should take a lesson from BP and do a very fast recall and beef up their forks. Even if they think they are theoretically blameless and users are dolts, if their forks break, they did it wrong. Plain and simple.

rustychisel
06-20-2010, 08:09 PM
that's pretty basic bottom line reasoning 11.4. completely agree. However at corporate HQ their bottom line is dollars and saving face. Maybe they'll make the right choice.

Mr. Squirrel
06-20-2010, 09:39 PM
.

http://forums.thepaceline.net/showpost.php?p=552555&postcount=7

nuts.

mr.squirrel

LesMiner
06-21-2010, 08:10 AM
A friend I ride with has a 2010 Madone similar to what was described in the article. He went through the whole Project ! thing to spec out the bike. The installation requirements quoted in the Trek response is not consistent with what Trek builds as complete bikes.

2) Always use spacers above and below the stem. Although less obvious than correct torque, a minimum of 5mm and a maximum of 40mm spacers under the steerer, plus a 5mm spacer above the stem are required. Riders should factor in these spacers when sizing their bike.

His bike has a Bontrager stem as installed by the factory. It does not have any spacers on the top of the stem. Trek's response to the issue does not seem credible. Most LBS's would not recognize this requirement from Trek. Doubtful that Trek has documented any cautionary instructions.

Dave
06-21-2010, 08:46 AM
Looks like defective CF material to me. Nothing to do with installation. If the CF is good, it would take an incredible amount of force to break a steerer, like the ones in the pictures. If I was injured due to this kind of failure, I'd be taking the fork to expert for testing. I'll bet the strength of the material is a fraction of what it should be.

The suggestion to use a 5mm spacer above the stem has been around for a long time. It reduces the chance of cracking the top of the steerer, usually caused by overtightening the stem.

I've been riding carbon steerers since 1999 and never had a problem of any sort with LOOK or Colnago forks.

Charles M
06-21-2010, 12:32 PM
I know lots of happy folks with Trek product too...


I don't think the company response is 100% wrong, but I don't think it's right either.


I think there comes a point where manufacturers want to reach a specific spec for their product and we're simply pushing up against material limits to make those spec's.

I think Trek need to manage expectations with their marketing people and customers as well as better educate retailers and customers...

They need to not be affraid to say "this steer tube is very thin and in order to have a bike in this weight class, you're going to have to take special precautions.


Trek also need to pay tighter attention to this, given their mix of customer. This is an enthusiast brand and also a brand that has a higher degree of rookie purchases... They all need to know what they're buying.



The carbon in the steer tube isn't bad. And the force required to damage it isn't all that tough to reach. I think most stems and bars are just fine if the proper care is taken to install, but I also think both Trek and mechanics and customers need to be honest with themselves...


There is no mechanic around that shouldnt be working with a torque wrench on modern top of the line race kit... ANYONE that thinks it OK based on working with past products is misguided abd frankly I know team mechanics that fall under the misguided tag.


No excuses for any manufacturer, but cutting edge product simply is what is is today...

benb
06-22-2010, 09:49 AM
Wielgasz pointed out that FSA stem bolts are marked with a maximum torque value for the bolt, but that doesn’t necessarily mean the part needs to be tightened all the way to that torque – it’s a max torque value for the bolt in the stem, but it doesn’t necessarily apply the steerer being clamped inside. “A trained mechanic should only apply the amount of torque needed to secure the part. Rarely should maximum torque need to be applied,” he said. Read more: http://velonews.competitor.com/2010/06/news/steered-wrong-racers-concerned-about-broken-carbon-steerer-tubes_121389/2#ixzz0rWYGwxLP

That right there sums it up.. the industry needs to get it's act together and specify all this stuff out the wazoo so stuff just works. If they need a specific mating surface to ensure safety, they need to specify it and/or make their fork incompatible with other designs. Just saying 1"/1.25"/1.5" diameter is apparently not enough. It usually doesn't even sound like the bikes are even engineered to ensure compatibility right from the factory.

We are all just guessing at safety when they are making statements like that... oh well.. must be nice making such big fat profits? And if they aren't they all need to go back to business school or stop charging motorcycle prices for bicycles.

flydhest
06-22-2010, 10:08 AM
This post is a very well written one and hits the nail on the head in my view. A couple of observations. Extra points for making "Trek" plural bys saying " . . .Trek need to manage expectations . . . " Don't know if it was deliberate or not, but it should have been and it should be the new standard.
Second, I agree that customers need to be more aware. What makes this case interesting is that the main guy is not a typical Sunday club ride enthusiast. I think that fact demonstrates just how much extra knowledge all the way around is needed.

My teammates that were in the race were pretty sketched out by it, but that's neither here nor there.

I know lots of happy folks with Trek product too...


I don't think the company response is 100% wrong, but I don't think it's right either.


I think there comes a point where manufacturers want to reach a specific spec for their product and we're simply pushing up against material limits to make those spec's.

I think Trek need to manage expectations with their marketing people and customers as well as better educate retailers and customers...

They need to not be affraid to say "this steer tube is very thin and in order to have a bike in this weight class, you're going to have to take special precautions.


Trek also need to pay tighter attention to this, given their mix of customer. This is an enthusiast brand and also a brand that has a higher degree of rookie purchases... They all need to know what they're buying.



The carbon in the steer tube isn't bad. And the force required to damage it isn't all that tough to reach. I think most stems and bars are just fine if the proper care is taken to install, but I also think both Trek and mechanics and customers need to be honest with themselves...


There is no mechanic around that shouldnt be working with a torque wrench on modern top of the line race kit... ANYONE that thinks it OK based on working with past products is misguided abd frankly I know team mechanics that fall under the misguided tag.


No excuses for any manufacturer, but cutting edge product simply is what is is today...

endosch2
06-22-2010, 10:14 AM
I was surprised about the idea of a spacer on top, that is the first I have heard of that.

I also was surprised about the idea that you can only use a Bontrager stem.

Seems like "The Great Trek Bicycle Making Company" is a little off the wall with this one.

Charles M
06-22-2010, 11:15 AM
The spacer on top makes sense in the case that it means that the expander plug is positioned in the correct place.

But then, so does providing the right exansion plug and bolt and top-cap combo in the first place... One that allows the expansion plug to sit right in the center of the portion of the stem that clamps the steer tube.
.

Most high end stems come with bolt torque spec's and all high end stems are designed not to cut into steer tubes to some degree (though mistakes can be made in forks and stems). Saying "X" stem is the only one that can be used is BS...

The fork manufacturer should tell you what critical spec their stem designs meet so that you can use anything that matches...


None of this is too difficult for bike companies to accomplish and communicate. And anyone not meeting specs and not using a torque wrench should have not room what so ever to complain about breaking something...

Marcusaurelius
06-22-2010, 02:33 PM
I suppose the durability of "cutting edge" frameset does cause me to pause a bit. I think I would rather have a little extra weight, maybe a 15lb bike instead of a 13 lb.

dcuper1
06-22-2010, 03:31 PM
Could the integrated headsets be exacerbating the problem? If you could use a Chris King Headset on the Trek Madone, would that keep some stress out of the fork?

spacemen3
06-23-2010, 10:56 AM
The local Trek store is always busy handling warranty replacement frames, and I'd expect the other brands face similar issues. Which leads to the question: How much margin do these companies build into their carbon bike pricing to handle the warranty costs?

redir
06-23-2010, 11:27 AM
I know the feeling of holding your handle bars in the air as you go down thinking ***? But in my case it was a broken alloy stem.

The Bontrager Stem on my bike has weight saving cut outs in it that Trek claims are not safe on their bikes. Hmmm I thought Bontrager and Trek were like Orio's and milk.

Nil Else
06-23-2010, 12:06 PM
Perhaps stems designed to be used with 1 1/8" shim sleeves (like for 1" steerer) are in the future? I mean having gigantic cutout holes in the steerer clamp probably is worse than better for steerer tubes, more so for carbon steerers (as is the case with the current stem cap design for carbon bars). I personally think the idea of spacers on top and bottom also is better than worse for what it's worth.

jlwdm
06-23-2010, 01:15 PM
I suppose the durability of "cutting edge" frameset does cause me to pause a bit. I think I would rather have a little extra weight, maybe a 15lb bike instead of a 13 lb.


It is interesting that when the minimum bike weight of 6.8kg (14.96 lbs) was enacted in 2000 the weight minimum was not a big concern because bikes weighed more than this. Safety issues were a big factor in adopting the rule.

I just looked at an article from 2004 though talking about how technology had changed so much since 2000 that safety should not be as big a concern. The use of lighter materials has made it easy to be well under 15lbs.

At a certain point many of these weight savings do not seem worth it.

Jeff

bfd
06-23-2010, 01:46 PM
The local Trek store is always busy handling warranty replacement frames, and I'd expect the other brands face similar issues. Which leads to the question: How much margin do these companies build into their carbon bike pricing to handle the warranty costs?

A couple of years ago, I asked a LBS about Scott frames like the 13lb Scott Addict and whether he had alot of warranty issues. Surprisingly, he said that Scott was a very durable brand and saw few problems.

He also sells Time frames and did say that one problem he had was Time threadless stems. He warrantied a ton of those because of the 2-bolt faceplate design like this one:

http://www.probikekit.com/display.php?code=K0212

He says all faceplate should have 4 bolts. Good Luck!

retrogrouchy
06-23-2010, 10:17 PM
The local Trek store is always busy handling warranty replacement frames, and I'd expect the other brands face similar issues. Which leads to the question: How much margin do these companies build into their carbon bike pricing to handle the warranty costs?

Answer: a whole, whole bunch! Not to mention covering the Marketing costs! :D

zap
06-24-2010, 11:20 AM
snip

He also sells Time frames and did say that one problem he had was Time threadless stems. He warrantied a ton of those because of the 2-bolt faceplate design like this one:


He says all faceplate should have 4 bolts. Good Luck!

Monolink stems originally supplied with ti bolts were a problem. Steel bolts fixed it.

Ti bolts should only be used with 4 bolt faceplate but I would replace those with steel after a season of hard riding.

I understand Ti performs poorly under shear loads. Al does better and steel best of all.