Crashed my road bike very hard while on holiday (carbon forks/steel frame).

Visually, the forks look fine, but I want to get them properly checked and ultrasound scanned before I ride the bike again.

Who does this in the UK?

Googling around I’ve found Carbon Bike Repair in Leatherhead – but they inspect via thermopgraphoc X-ray rather than ultrasound.

Maybe I’ve watched too many Leuscher Teknik videos, but he knows what he’s on about and only recommends ultrasound.

Suggestions/recommendations please..?

I had a bad stack on my road bike last year and was concerned about the forks. I replaced them in the end for peace of mind. I then smashed the old ones up to see how weak they might have been – took a lot to break them but still felt new was the way to go.

Just do a tap test. If that seems fine then I wouldn’t worry.

You choose the NDT technique to suit the feature you are looking to inspect. Some geometries ultrasound is not the right tool for the job. Best to just take the forks to a specialist and get their advice. Or just assume they’re knackered (in all likelihood they are) and just replace. By the time you’ve paid for NDT and had them inspected you might not be able to get a 100% ticket of health, there may be some ‘yes but…’ element then do you really want to take the risk? I wouldn’t. You might be able to get a good deal on a crash replacement fork from the manufacturer.

Tap tests only really work for thin laminates. They won’t tell you about any de-lamination deep in a thicker section like where the crown and steerer meet.

We do at work amongst other things Ultrasonic testing via a subcontractor. It’s £50 minimum order charge. Maybe a bit cheaper if you don’t require a testing cert. Personally for piece of mind they’d be going in the bin if they were mine. I don’t bounce as well as I used to.

Laminates are tricky to NDT. So are complicated geometries (e.g. the crown interface and stuff.).

To be sure, I’d leave it. Impact damage on one point you should be able to see, but if it’s started to fail from a large overstress it’s a different kettle of fish.

It kind of should be OK if you can’t see any damage but I’d probably just look for some keenly priced replacement forks – which will be competitive cost wise with inspection and give you better peace of mind.

Unless the frame was OK, in which case I’d probably not worry about the forks too much.

What kind of crash was it?

Unless you hit something front-on and went over the bars, or it was an impact with something and there are signs of visual damage to the forks, particularly around the crown or along the blades then I wouldn’t worry about it too much – they’re pretty strong.

I went OTB on a pair of forks on a road bike years ago – since then I’ve raced them hundreds of times and ridden Paris-Roubaix and Tour of Flanders at least a couple of times each

It was the kind of crash where I went OTB, the bike ejected itself from me, spiralling through mid-air and slamming hard into a static caravan, before then crashing to the ground.

Amazingly, the (steel) frame and (Carbon) fork seem unscathed, but the impact was hard enough to destroy the seat, crack the seat clamp on the post (never seen that happen before), buckle the (brand new) rear wheel, and muller the bars, tape and other bits.

I may be being overly cautious, but I’m nervous about riding the carbon fork again without it being checked out properly. My life depends upon it, so why not?

Both frame and fork are straight and unscratched…aren’t carbon forks way stronger than steel forks…hence would have damaged the frame before being damaged themselves?

“Life depends on it”…if they are damaged, surely you’ll only know when they are involved in a significant impact, in which case there’s going to be all sorts of things going wrong? Or will they fall apart JRA?

The frame would have bent first. Pull the forks off and check for any damage. I’d say fine having seen how strong mine were after my back snapped instead.

aren’t carbon forks way stronger than steel forks

Maybe, maybe not..probably not as strong as Steel…depends on how they’ve been designed and made and how well they’ve been made – you can easily crush a carbon steerer if you’re a bit ham fisted when tightening the stem bolts – no chance of doing that with a steel steerer, you’ll strip the bolt or stem threads before you crushed the steel steerer – or aluminium steerer for that matter. Carbon is not the wonder material everyone thinks it is. The problem with carbon is when it tends to fail catastrophically with little or no notice, it doesn’t bend or deform thereby giving the rider some notice before ultimate failure. You can get away with it on a chain stay or a seat stay, but for a critical component like forks or handlebars, best not to take the chance.

Sounds like the saddle and back wheel took the brunt of the impact, followed by the bars and levers. I’ve seen bikes that have been in front-end impacts where the front wheel and forks were find, but the head tube was distorted.

No worries. I’ll take the forks to that place in Leatherhead.

Wobbliscot, the steerer is not relevant, the whole point of carbon is that the strength is where it’s needed – around the crown etc where the stress is. This is how it is lighter.

Also – metals fail without bending in a previous impact.

And the whole “I wouldn’t risk it” argument just ignores any science.

Dovebiker you are taking about 2 impacts here, the saddle got it in the 2nd, which won’t have affected the fork like the 1st.

Into a static caravan?

Were you late for Bingo?

How did you go over the bars in the first place? Front brake or hitting something? From your description it sounds like the big (static caravan) impact happened after the initial off.

In what way were the bars mullered? i.e. Do they indicate a vertical impact through the bars and stem that could have damaged the top of the steerer?

In these current litigious times is there any company who will test a crashed carbon fork and give you a 100% guarantee that they are safe to ride ? If there was the slightest bit of doubt in my mind I wouldn’t ride them or every time I went down a fast descent I would have , at the back of my mind the thought of what would happen if my forks failed . Also in the great scheme of things a new set of carbon forks don’t cost that much . Also I would be interested to know how the I wouldn’t risk it argument ignores any science . It would be just as easy to argue that the whole it will be alright argument ignores any science .

Try Target composites.

Also I would be interested to know how the I wouldn’t risk it argument ignores any science . It would be just as easy to argue that the whole it will be alright argument ignores any science

People using the former aren’t applying much science…

Thanks to @Rick Draper for the recommendation of Target Composites.

The forks have been ultrasound scanned and they are trashed. The steerer tube shows significant delamination from ‘point loading’ – presumably where the impact shock has been been transmitted during the crash through the bars and stem to the carbon steerer. It is dangerous to ride and I’m replacing the fork.

To all those who said that if the fork ‘looks ok then it’s probably ok’ this is a lesson. The fork showed no visible signs of damage at all – yet is damaged and is dangerous.

We take our lives in our hands if we ride carbon stuff that’s been in a crash and isn’t properly tested afterwards.

Wow! Every day is a School day. Good job on getting the scan.

@Digger90 – how much was the scan if you don’t mind me asking?

I assume not so much that you might as well buy new forks anyway?

The scan was about £70 – the new forks, with paint, are £420. So very worthwhile doing the scan.

I’d be interested to know how easily the old forks break now – are you going to do some destructive testing?

@Digger90 Did they give you an image of the damage? Can you show it?

@Digger90 Did they give you an image of the damage? Can you show it?

Nope, sorry. The forks are still with them…

To all those who said that if the fork ‘looks ok then it’s probably ok’ this is a lesson. The fork showed no visible signs of damage at all – yet is damaged and is dangerous.

Not having seen any pics of what you’ve seen I would ask are you sure it was like that from the crash.
One of my first bikes was a cannondale, alloy and it was xrayed and on the xrays it showed stress fractures around welds. This was nearly new, and I took from that that they would be there from new and were therefore nowt to worry about.

Im asking is if you scanned a brand new fork, would it scan as solid, or would there be de lamination, that would be expected from the manufacturing process but still be within safety margins. I mean if it was visible to the outside then it would be obvious, but I wonder if today you scanned everybody here’s carbon forks, would you see solid, or a series of cracks, or de lamination.

Persoanlly i’m with everyone, and dont take the risk 😕
But it asks if every carbon fork is safe to buy and not just 2nd hand, if the damage is hidden deep inside.

I found a crack in one of the forks on my bikes and i’ve stopped using 2nd hand forks since! I got a little paranoid after reading about similar incidents…

https://cycling.today/more-stories-about-potentially-deadly-carbon-bikes-emerge-after-stanton-case/

https://cyclingtips.com/2016/12/after-the-death-of-a-canberra-cyclist-should-you-be-concerned-about-catastrophic-fork-failure/

https://www.cyclingweekly.com/news/latest-news/cyclist-died-carbon-forks-separated-inquest-hears-231824

Im asking is if you scanned a brand new fork, would it scan as solid, or would there be de lamination, that would be expected from the manufacturing process but still be within safety margins. I mean if it was visible to the outside then it would be obvious, but I wonder if today you scanned everybody here’s carbon forks, would you see solid, or a series of cracks, or de lamination.

Trek promote ‘OCLV’… not ‘OCNV’.

To all those who said that if the fork ‘looks ok then it’s probably ok’ this is a lesson. The fork showed no visible signs of damage at all – yet is damaged and is dangerous.

And an important lesson about composites. Damage doesn’t necessarily manifest itself at the surface. Metals can fail catastrophically but only if the energy levels are massive. In the application of a bike components and the sort of energy levels in a bike crash metals will yield first and damage will be obvious in deformation and/or cracking. Not so with carbon where the damage is usually internal and invisible at the surface. Even with car crashes and the high energy levels involved there cars don’t catastrophically fail, the bodies and structure bends and deforms.

Well done OP for taking precautions. I’d say in 100% of cases following a crash where the forks have taken a substantial impact they’re knackered and just need replacing. That’s the price you pay for light weight and high performance…. you pay with durability.