[Closed] On One carbon fork death.

Want a fiver for it? I want a broken carbon fork for an experiment.

I noticed that the disc caliper started to come out of alignment with the disc.

What do you mean exactly? I'll give you £6

£4 offered!

Clydesdales and [s]carbon[/s] normal components do NOT mix

Nothing wrong with carbon.

Cynic-al, as in after rocking the bike back and forth, then wheeling it away the front disc was catching against the pads. The calipers have not needed any further re-alignment for the best part of a year.
What kind of experiment could you possibly want to do with a broken carbon fork? No actually, don't answer that.

Molgrips, I agree there is nothing wrong with carbon, but how come the more expensive carbon forks have a rider weight limit?

I'm not familiar with On One forks.
Is the drop out and caliper mount not all one lump of aluminium bonded to the bottom of the CF tube like a Nuke Proof ?
How is the caliper moving in relation to the disc ?

Wow.

Bike component has finite life and will break.

Is this a carbon specific feature, or do non-carbon things sometines break? Is it part of the warranty that you complain on a forum before doing anything else?

I think if you have any comment on part of your bike (positive or negative) the bike section of a bike forum on the Internet is probably the right place to discuss what happened and what might come of it.
Where would[i] you[/i] discuss it to gain opinion on whether you have a valid complaint- Before (obviously) taking it up with the vendor or manufacturer?

I was thinking about looking for an example where carbon failure is progressive and detectable before total failure and you just provided it.

Laughed when I read the review of the carbon whippet in MBUK:

They claim that carbon fibre suddenly breaks but aluminium doesnt. I want to meet the guy who wrote that.

PS everything breaks. How long have you had it. What size brake disc, do you ride quite rough etc etc. If under 2 years you could make a warranty claim.

I'm still confused.
http://www.on-one.co.uk/i/q/FOOOCAR/on-one-carbon-fork
[img] [/img]
The caliper and front wheel are bolted to the same aluminium part.
How does failure of the carbon part cause them to move in relation to each other ?

i dont fully understand what is broke
if you can see movement in the caliper/rotor for all we know your caliper bolt needs tightening up.

any pictures of the failure or further description of what section has failed would be good.
also how clydscale are you 😉 in kg?

Maybe this one:
[img] [/img]

Okay, I have e-mailed On-one on Monday (granted it was a bank holiday) and am going to wait until tomorrow before I call them as my work allows. The forks are 16 months old, I am 6'3" and weigh in at 16 stone (and before anyone says, my last health evaluation stated I was carrying 1/2 stone of excess). I would state that the bike has been used mainly to commute and on smoother trails where an FS is over biked.
In reply to Grahams post, I would only assume that as the aluminium crown and droputs are bonded to the carbon, that either the bond at the crown or the dropouts (or both?) has failed, causing the sideways flex and the disc alignment issue.
As Andyl stated, the internet is a fantastic resource of real life reviews that aren't swayed by product persuasion. I'm not suggesting that On-one have ever done that, they have a fantastic company with great offerings and I will not hesitate to use them again. But if I could have read a similar account to mine of using carbon forks 16 months ago, it may have made me think twice. All I read was glowing reviews from people of a similar weight as me.
I have posted my experience purely for people to discuss and compare. I'm not bitching about stuff breaking, I've been breaking bike parts since my pre-pubescent years and I'm now getting scarily close to the big four-o.

MTQG makes my point...I still don't understand what's burst.

Cynic-al, I know what you are thinking, that any lateral movement should be matched with the movement of the disc as it is bolted to the hub which is aligned through the dropout on the axle. But if one side twists and not the other, then as disc pad clearance is what 1-2mm at best? then the pads drag on the disc. It is not a loose caliper bolt as suggested by somebody else, I have to loosen the caliper to realign it and the re-tighten it. Then after further cracking sounds, the caliper is out of alignment again.

tbh reading about your fork breaking has actually made me more likely to buy some in future as they didn't snap in half and kill you.

Forks are very highly stressed parts. The steel on-one forks weigh almost as much as my carbon 456 frame!

Please get some pics up as I would like to see how they have failed.

Unless there is a crack/break between teh LH drop out and brake mount then it's not the forks.

Andy, there is no picture to show, there is no obvious shearing apart or misaligned crown/dropout etc. It's all in the sound of cracking and the caliper becoming out of line, which is probably only slight at that but enough to cause drag due to the tolerances mentioned earlier.
I'll more than likely go for a Salsa Cromoto fork to replace the carbon one, just for peace of mind, I'm not sure of the weight difference, but I imagine the real difference will be in the ride.

Al, you sure live up to your user name 🙂 True test will be when a different fork is fitted. I'll let you know.

I just can't see how the brake mount could move relative to the dropout otherwise.

Oh and that would be sceptic-al 😉

I am guessing it is the bond between the carbon tube and the alloy drop-out or crown that has gone.

Al - a QR fitting WILL flex and if the fork is broken there will be the possibility of the drop outs moving relative to each other which will result in the caliper losing alignment with the disc.

Take the wheel off and wiggle the drop outs - simples!

Are they 26 or 29" ?
Also, looking around the join between the carbon leg & the drop-out, is there what looks like a bead of silicon or is it just open ?
Only asking because on the 26" version I had there was what I'd describe as a bead of sealant of some kind over this join. (Kind of like around a bath if you know what I mean), whereas on the 29" version I have now, there is no sealant. Its just an open joint & I wondered if this might allow water/muck in & affect the bond. Just a thought.

What about stretching a peice of selotape tightly across the join then recreating the cracking sound & seeing if the tap has been moved/creased/broken...

nail varnish is very good to put over joints to see if there is movement.

I'm using my Nuke Proof carbon rigids for MTB in the Yorkshire Dales. I don't claim to be a downhiller, but they (and I) get a battering on the down hill bits and they are going good so far.

I broke some Pace forks a bit like this. The dropout twisted on the carbon leg, and the carbon leg twisted in the crown.

I have some old Pace RC40's. The disc mount cracked so Pace removed & replaced the drop-out / disc mount bit, from the carbon leg. Its taken another 4yrs punishment since without any problems, so it could probably be repaired. If O-O dont want to know ask Fork English ?

Starting craking a couple of weeks back

Bugger my 29er version has started to do the same too & I noticed that the disk is rubbing next to the fork stanchion to when I am climbing too!

Runs off to check life insurance policy 😯