AlmostTrick

Not always true. As previously posted, I commuted for 8 years on a CF fork (and seat stays) with no problems whatsoever. All the thousands of miles of pounding left me more concerned with possible damage/failure, not less. Nothing lasts forever... except love.

Re: safety. Fork failure is fairly rare, regardless of the material. But CF and steel can't both be the same: One material or the other has to be even less likely to fail in a crash inducing manner than the other. How many people who have actually researched the topic can honestly say CF is less likely to fail than steel?

Even if small, why take unnecessary risk? To save a pound? On a loaded touring bike? Seems misguided to me.

79pmooney

You rode that steel fork for a week fully broken and nothing happened. In my book that is a gentle failure. Everything fails sooner or later, everything. There are no exceptions. Some don't fail in our lifetimes. But those items that do fail in our lifetimes - do they fail in a way that we get injured or is just an inconvenience and maybe a scare? We both have ridden bikes where the forks failed while we were riding. And we both rode those steel forks home with no issues except needing to replace them. I call that a success.

I try to ride better quality forks that won't fails soon, but that mode of failure is one I am comfortable with. Three forks on that bike's successor failed, all steel, all in hard frontal crashes and all three could have been straightened to continue a tour. To get the the point of this thread, that is why I will always tour on steel forks.

Ben

grolby

I don't really agree with this mindset on risk - if the risk of failure of X is somewhat higher than the risk of failure of Y, but the overall risk is very low, I don't see much reason to further manage that risk by avoiding X. For example, say living in a coastal state means my risk of being attacked by a shark is probably somewhat higher than my risk of being attacked by a shark when living in an inland state. Does that mean I should move back to Tennessee? Better safe than sorry, after all! But of course that's ridiculous - there are much bigger factors in my overall exposure to injury risk than proximity to sharks, over which I have a lot more control. Same thing in riding bikes. My riding behavior, how diligent I am about maintenance and countless other factors have way more influence on my likelihood of getting hurt while riding a bike.

Obviously, a silly example, and I'm not really trying to tell anyone they SHOULD use a carbon fork on a loaded touring bike. It doesn't really matter. Heck, if I were in the market for a loaded touring bike, I'm sure I would end up with a steel fork, because there are few alternatives even available and they're not worth the hassle. But then, I'm not really interested in loaded touring these days, I would rather do shorter trips and travel as light and fast as I reasonably can. Weight definitely does matter to me (loaded touring was ruinous on my knees), and light weight means I could just use my road or, more likely, my cyclocross bike. Both of which have carbon forks and neither of which concern me.

Except, as I already explained, the fork was held together entirely by the front rack of the bike. There was nothing gentle about the failure - the fork leg was cracked completely through. Maybe without the rack I would've noticed the vibration getting worse and figured out why before the fork failed completely. Or maybe the handling would've gone weird without the rack to keep the fork from twisting as it cracked, and that would've clued me in - or caused me to crash. Or maybe I would've assumed the same thing I did with the rack there, that the vibration was just brake shudder, and I would've ended up eating my own teeth. It's easy to be blase about something like this when it's someone else's bike and say "well, it's steel and you rode on it for a week so it's NBD," but I'm not blase about it at all. On the other hand, it's not like I'll never ride a steel fork again because that one broke. That's nuts. But it was a lesson that anything can break, especially if it's a used bike with a history not entirely known to you.

djb

Grolby, very reasonable comments. It makes me think of the whole airline safety record thing, of the billions of flight miles vs accidents. There must be millions of carbon forks out there in Canada and the US and the vast vast majority live lives like my carbon fork, ridden and stored without impacts other than the specifically designed "hitting a pothole" sort of thing, and are fine.
Knowing my bike history and how it's ridden, even my rare case of a cf fork with low rider eyelets, really does come down to percentages, ie your shark example.

saddlesores

well here you're moving from a slight risk area to a high risk area....you're substituting
non-related risk factors.

you might be a lower risk of shark attack in tennessee....assuming you stay out of
sea world type attraction....yes....you COULD fall into the shark pool. or you could
be one of the unfortunate few that travelled upstream. or you could be within the
kill zone of the military's new top secret killer robot land shark. but these are not
likely.

but you'll be substituting much more risk..........more risk of bear attack, packs of
wild raccoons in your favorite park, pestered by hordes of religious zealots, made
to squeel like a pig, or the ultimate terror....frau hillary moves in next door.

regardless, in case of any of these new threats, you're more likely to be able to
fight them off with a durable steel (even inferior LHT steel!) fork than with a
brittle carbon fjork.

grolby

The problem with fighting off robo zombie sharks with a carbon fork isn't brittleness, it's the lack of weight! Hard to do any real damage with it. Here's a fun test - not super scientific, but fun. Take a discarded carbon fork, hold it by the steerer, and wail it on a solid object. Like a cinder block, or a boulder (wear eye and hand protection!). See if you can break it. I can pretty much promise you, you won't be able to do it. It doesn't prove a lot, but it does help demonstrate that carbon fiber isn't like pencil lead. It's a lot tougher than people think.

mrv 

yea... pretty much....

https://vimeo.com/106021360 - apologies if the video done been posted.

PS - yes, as I mentioned when I got into this thread - I do have a bike with a carbon fork! I'm ok with it. So much so it's my son's bike. It's like my second carbon fork and everything. Still not sure I'll use it for touring. But .... maybe!

djb

its all fun and games until someone has to call Saul.
cute vid

damo010

The forks in the above video are skinny roadie ones, if you want strong carbon get MTB stuff!!!!

check out this carbon testing;
https://www.youtube.com/watch?v=xreZdUBqpJs

damo010

carbon vs steel fork video:

https://www.youtube.com/watch?v=6QNRpSkTGoA