I don't know about that. How many people fail to take their bike for a post-shipping "shake out" ride?

I believe that the Dash saddle rails are Kevlar and not Carbon, not sure of the strength differences between the two.

Maurice

I think that a failure like this will usually happen over a period of time. After the worm/ring gear teeth are damaged, the gearing grinds itself to death due to the sliding friction between the worm and the ring gear. Worm gear drives are very reliable but can fail in this manner....from nylon gear sets in garage door openers to steel/bronze worm gear sets in industrial gearboxes. Heather was here for a relatively long time (4 weeks?) before the race and would have done a lot of riding, post bike assembly. Just sucks to have this weird failure mode go the distance on race morning. Shimano has all the information in their hands to get down to the root cause of the problem but with the preponderance of di2 systems out there with millions of shift cycles and the lack of this kind of issue, one has to believe that there is very low likelihood of systemic design issues. Imho, Shimano has done a stellar job designing and deploying this system.

The history of cycling is replete with crank failures. Most notorious have probably been:

1) 1970s era Campagnola Record;

2) 1980s era Shimano Dura-Ace AX (broke two or three myself, and I'm generally pretty each on equipment);

3) 1990s (?) CNC-machined cranks, e.g., Sampson;

4) 2000s FSA carbon cranks (frequent failure at pedal hole).

Etc.

Carbon is stronger. Kevlar is tougher. Most of the time, you'll see intelligent combinations of the two when it's done right. Carbon internally for structural strength and rigidity. Kevlar externally for toughness.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

"1970s era Campagnola Record"

i snapped one of those. landed on the top tube, right on my nuts.

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Dan Empfield
aka Slowman

Back in the days of steel steerer tubes and quill stems, it was common for racers to set up their bikes with the stem not very tight in the fork - the rationale being that in a crash the bars would turn rather than bend or break. Didn't take much force, but there bars/wheels don't get hit from the side riding anyway. I did it that way and could center the bars by holding the wheel in place and pushing hard.

I'm not sure that is appropriate with a carbon steerer (and don't use one) nowadays.

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http://www.jt10000.com/

I have two Dash saddles, the rails are Carbon/Kevlar weave. The rest of the saddle is Carbon.

So much for titanium. Was torqued to mfg specs too. Any word from john?

Yes. He'd seen the problem, but not with any sort of regularity. It seems it is not a problem with the saddle rails. It's a problem with the saddle rails when they are clamped in certain hardware. John said he saw it the most with Cervelo's clamps, but they may also be a function of Cervelo's popularity.

In any case, that's why he redesigned the saddle to use Cro-Mo rails last year.

But he's redesigning the seat again, and I'm going to help with it. Might see if we can get someone to do FEA on it. Here's what I know:
- I've ridden an HC or SHC 170 saddle from 2009-2015 (except for 2014) without an issue. Probably 50-60,000 miles. And I would typically ride a saddle for two years or more. In that time, I had three different types of clamping hardware: Thomson and Specialized and, for 2015 only, Dimond. This was my first issue.

- The problem clearly happens, but it's not overwhelming. I described it as unlikely, but definitely not impossible or even improbable. And it seems, at first glance anyway, to be a function of more than just the saddle.

- John has seen it with the Cervelo most often, but I haven't asked what other bikes are on the list. I have now seen it with a Dimond. My friend Jay saw it twice on a SpeedConcept, but using the old-style clamp that was identical to the Specialized clamp that I never had an issue with.

So, basically, there is no clear conclusion. It was enough a problem that John switched to cro-mo, but not enough of a problem that I couldn't log countless miles without an issue until Saturday.

I do note that Kraig Willet's broken Fizik also had solid Ti rails. And that Fizik no longer uses solid Ti but instead carbon, cro-mo, or a their own proprietary k:ium alloy. Hollow metal rails seems like a better idea to me than solid, as they should be more likely to buckle than fracture.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Ive broken two Al cranks, and one BB...and Im not a big guy whatsoever. It happens.
Stephen J

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I believe my local reality has been violated.
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Happiness = Results / (Expectations)^2

I guess they should have gone with Aermet.

Stephen J

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I believe my local reality has been violated.
____________________________________________
Happiness = Results / (Expectations)^2

I was thinking more like adamantium

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

I am surprised by the number of people who reported their stories about broken cranks (including Dan and Andrew Coggan). I am just surprised, because I started riding in 1980, and never seen a broken crank in real life and never heard of any training partners breaking them, and never seen it happen in a protour cycling race or pro triathlon race or any of the local/regional/national events that I have been at. Literally this thread is the first time I hear of everyone with cranks cracking/breaking. I am still curious what happened to Jeff Symond's crank...whether it cracked or if it came off the spindle.

Jeff confirmed to me after the race that the binder bolts came loose (or were loose) and that it came off the spindle.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Thanks Jordan. Mine was in a Blue Triad, so not sure what actual type clamp they use. I'm nowhere near the mileage guy you are and it lasted a year at most. Pretty disappointing I must say. Back searching for the right saddle.....

I appreciate your insight and the candid words.

Hello Rappstar and All,

Perhaps this is the future ..... where we don't need no stinking rails .......... from 60 years ago.

This is a Dash saddle and seat post ........... but a seat post adapter and a fastening plate attached to the saddle (like my Adamo with rails removed) should work just fine. Tilt can be adjusted with shims and wedges.

If you need a bit of vibration relief ...... put in a thin pad of elastomer material before fastening it down.

If you need a lot of vibration relief cut a piece out of an old Hoka shoe sole and put it in there.

Also this clean design will put more air to the low pressure area behind your butt and should make you a bit faster ........ and it will be damn hard to break.














.

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Cheers, Neal

+1 mph Faster

I just posted the video of Jeff riding by at mile ~95 or so on the bike and the crank arm is intact - it may be loose, he was unclipped and pedaling with one leg.
https://www.facebook.com/...?v=10207744664120581

-SD

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https://www.kickstarter.com/...bike-for-the-new-era

I wonder if the bolts were loose and as a result he stripped the splines by pedaling...

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Was Brad really competing barefoot? Awesome athlete back a couple of years. Barefoot on Hawaiian tarmac sounds risky

Don't think Brad ever did Hawaii. Focused on short course, ITU, F1, etc. He ran barefoot at an indoor race in France (in the Velodrome). Very short stuff, spectator-friendly taking place in the Bordeaux Velodrome (they did another one in Paris Bercy too the same year I think).

Man that's a weird break.

9310 will get you 95% of the way there for 10% of the price :)