How old is too old for carbon forks?

[Binaural]

I've got a set of 3T forks that have done about 8 years of service on my daily commuter . However, I am starting to wonder whether I need to replace this as a maintenance item. While I understand that carbon parts don't have a definitive fatigue life like metals do, I weigh about 110kg+ and have ridden the bike to work with a heavy bag most days. From what I've read, any fork failures are likely to be progressive and difficult to find by inspection. I've crashed the bike a couple of times, but as far as I know never into anything.

So far I've done a "tap test" as suggested by Zinn and it doesn't sound too dull, and there does not appear to be any sign of surface delamination. Problem is, I have no idea what it used to sound like years ago, so I don't know what's significant or not. It is literally the only thing left over from the original bike, everything else has broken and been replaced.

Since I'd only be replacing this as a preventative measure, is it worth it or am I just being paranoid?

 

[The Reverend]

It's difficult to know for sure. All I know is that I binned a probably perfectly good set of carbon handlebars when I thought they looked suspect.

Currently sitting through shoulder reconstruction surgery rehab and I'd do anything I could to avoid it.

Personally, I'd bin it and move on unless I just couldn't afford to replace them but compared to the cost of surgery or living with potential injury it's a small price to pay.

See what others think...

 

[Oddjob]

Can you send them off for inspection to a carbon specialist? I'm assuming that the fork have a carbon steerer.

I have a Lynskey carbon fork with an alloy syraight steerer which I' m starting to get worried about and will send it for checking soon. I bought a Carver fork in preparation.

Sent from my SM-G970F using Tapatalk

 

[Flow-Rider]

You blokes are starting to get me worried but I'm only 80kg, I have some on my commuter that are about 6 or 7 years old. I would assume a proper inspection would not be cheap and almost the cost of a new set.

 

[silentbutdeadly]

Since I'd only be replacing this as a preventative measure, is it worth it or am I just being paranoid?

It's not worth being paranoid...

Carbon fibre is basically fancy fibreglass. You don't throw your boat away every five years do you? There's no reason to imagine why such a fork would fail unless there was something to propagate that failure like a dodgy crown race or similar.

I'm running a 6-8 year RS World Cup SID fork with carbon everything but the stanchions and I'll be stuffed if I'm binning that for fear of breaking 'old' carbon fibre!

 

[Mr Crudley]

You blokes are starting to get me worried but I'm only 80kg, I have some on my commuter that are about 6 or 7 years old. I would assume a proper inspection would not be cheap and almost the cost of a new set.

I have some old CF Kinesis forks on the first roadie. Admittedly I haven't rode this one for a while and it is on loan to friend.

Those forks are no lightweights and pretty burly for a road fork. If anything gives out first it would have to be the bonding agent between the alloy crown and blades. Still worth a check though I guess.

 

[Daniel Hale]

I have a carbon fork on an old Lemond steel road bike dating to approx 2002-03, still seems to be riding fine--if you're worried id be calling Raoul at Leuschner Teknik, he is the carbon goto guy , he's a straight shooter - he ll tell you what the deal is

 

[Binaural]

If anything gives out first it would have to be the bonding agent between the alloy crown and blades. Still worth a check though I guess.

The 3T forks I have are single-piece and don't have an aluminium steerer tube, so that's quite helpful. The really dangerous failures I can find seem to be related to this junction.

This link with responses from a bunch of reputable manufacturers put my mind at rest. So long as there's no crash damage, it seems that I have nothing to really worry about despite the cruel life they've lived. That said, a fairly minor crash would be enough for me to make a call on replacing these. Thanks for your input everyone!
https://www.velonews.com/2002/12/technical-faq/technical-qa-with-lennard-zinn-carbon-forks-2_3270

 

[Flow-Rider]

I have some old CF Kinesis forks on the first roadie. Admittedly I haven't rode this one for a while and it is on loan to friend.

Those forks are no lightweights and pretty burly for a road fork. If anything gives out first it would have to be the bonding agent between the alloy crown and blades. Still worth a check though I guess.

I've got one of the first composite GT GTR road bikes where the front tubes are expoxied together and the rear stays are carbon, it's got some separation in the rear stays where they dowl into the carbon, you can see a nice straight split in the paint, I hardly ride the bike but it's been like that for many years.

 

[c3024446]

I had a kinesis 1" carbon fork / alloy steer on my 99' Litespeed. Was pretty heavy and had no evidence of anything going wrong with it, but I replaced it with a Ritchey 1" one 12 months ago just in case. Bought the bike used 5 years ago and had no idea on its history.

Carbon fork / alloy steerer would be of higher risk than a full carbon fork (assuming you have this?). Take it out, inspect it for cracks. Do this whenever you feel like it's been a while since you've inspected it.

 

[PJO]

I rode a set of carbon forks (Al steerer) on a low/mid-spec Merida road bike for about 8 years, was always in the back of my mind that they could fail but they never did, and didn't show any real signs of wear. They weren't the lightest build though...

I replaced them last year (and the whole frame) with steel. Feel much better considering I ride a road bike with the same attitude that I ride a mountain bike, jumping curbs, bunny hopping pot holes, etc...

 

[ozzybmx]

Just promoted a set of 2011 PRO Components carbon forks back to the premiership.
Sat on the shelf for a few years since coming off my rigid HT and singlespeed. Now on the bikepacking bike... didnt even think twice about it.