I was waiting at a red light and the person behind me hit me. Her car ran over my rear wheel crushing it and over my frame. I have checked the frame were there are indications of her car but do not see any cracks.

I tested with a coin and did not hear anything and had my bike shop look at it. When I am riding I can reach speeds up to 50 mph. I have not ridden my bike since being hit for fear of underlying cracks I cannot see. Can I trust my frame when I am reaching at such high speeds?

I’m working with the driver’s insurance company and afraid that if I can’t prove a crack then I cannot get approved for a replacement. What is the right approach to ask for what is needed?

  • 5
    Your bike frame is not built to stand up to that kind of punishment; I wouldn't risk it at all.
    – DavidW
    Commented Jun 1, 2023 at 14:00
  • 9
    There is a breed of lawyers called "personal injury lawyers". Normally we all hate them. But you need a lawyer to represent your rights, and this is one case in which such a lawyer may be your (future) guardian angel. No personal injury is involved, but the simple worry about your future well being is enough. Replacing your bike is most likely a given. You may have other rights in your jurisdiction. Only a lawyer will tell you.
    – Sam7919
    Commented Jun 1, 2023 at 14:07
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    For your next bike, I urge you to get a powerful rear (and front) blinking light. They are sometimes called "daylight light" to indicate they are powerful enough to be visible even during daylight. In my experience cars notice me a long time before approaching me, and they leave considerably more distance between them and me. In no way does a suggestion to use lights absolve the person who hit your bike from responsibility. It is simply that I see too many idiots staring at their phones while driving, and reducing the chance of ending up in a morgue is, obviously, also in our best interest.
    – Sam7919
    Commented Jun 1, 2023 at 14:19
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    @Willeke There is seeing and there is peripheral vision. Try it. Look down on your phone (and then your eyelids will be half-closed), and set up a distant flash light way out at the edge of your field of view.
    – Sam7919
    Commented Jun 1, 2023 at 18:24
  • 2
    @Sam no blinking light, please
    – njzk2
    Commented Jun 2, 2023 at 17:27

5 Answers 5


Ideally, you should find someone who repairs carbon composites and who has ultrasound imaging equipment. They can detect delaminations (i.e. invisible fractures under the surface of the carbon) that aren't apparent with the tap test - which may work OK on flat surfaces, but bikes tend not to have many of these. Raoul Luescher, who repairs carbon bikes in Australia, considers the tap test to not be that informative. Some sort of expert testimony would probably be important in establishing that the frame is damaged.

I don't know how prevalent these shops are, but there may be more than you think. For example, in or near(ish) to where I live, a Google search highlights Appleman Bicycles in Minneapolis and Cyclocarbon (which used to be about 2 hours south in Rochester - Google missed the relocation). You could also ship your frame to someone else in another state. Be aware that Google Maps will show a lot of false positives (usually bike shops). If you find someone with experience in aerospace but not bikes, you might consider approaching them nonetheless. Nevertheless, this type of expertise is specialized. Ordinary bike store mechanics won't be able to do this. Framebuilders specializing in metal frames would be the same.

You should seriously consider approaching a lawyer who specializes in personal injuries. They will be familiar with negotiating with auto insurance companies, and they will know what sort of proof is required to get the company to reimburse you. Typically, you can choose between paying an hourly rate or a contingency fee (usually 30% of the settlement amount). Yes, this is expensive. However, this may not be an area where you want to go it alone. Note that a laywer can also help you quantify other monetary damages, e.g. damages related to any injuries you sustained in the incident.

You could consider seeking some sort of statement from a carbon fiber repairer first, and approaching the company with that. If they detect no damage, I would still count the inspection and shipping as damages you incurred. You could naturally threaten to seek legal representation to encourage the insurer to settle. You might also consider cross-posting to the legal stack exchange.

If you do this, I would make clear to them that:

  1. Carbon fiber bikes can take damage from a rear impact that a) isn't visible to the naked eye and b) can cause the frame to fail later. Thus, I would not trust a carbon frame that had taken a rear impact like described - actually, the same might hold of a lot of metal frames.
  2. It's not simple to detect this type of invisible damage. It typically requires ultrasound or similar imaging. Almost no bike stores have this expertise. So unfortunately, there may be transaction costs.
  3. From the written description, this was a hard hit. This is much worse than a crash while riding. The car made direct contact with the bike frame, plus there was force transmitted through the hit to the wheel. I suspect most performance bike frames would be compromised in some fashion, period.

Overall, my advice is more conservative than I suggested in this answer about what to do if one isn't sure if your carbon bike is safe. Generally, you become unsure if you take some sort of moderate impact or you scrape the carbon a bit. With what happened in the written description, I would tend to assume the bike is unsafe unless proven by inspection (by a qualified person, not an ordinary mechanic at a bike shop who's just going to do a tap test that they may not know how to interpret).

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    Just worth noting, Cyclocarbon has moved up to Calumet MI. They're no longer even vaguely local to the MSP area (though, of course, you can still ship frames to them for testing and repair). Commented Jun 2, 2023 at 16:34

No one can say for certain the frame is now safe to ride without ultrasound imaging. Bike frames are designed to handle normal use forces of riding and maybe a crash where the rider falls off. They are no designed to be useable after being run over by a car.

Insurance companies are pretty much obligated to follow manufacturer process and repair/replace guidance, and it this information is what you need to know for your own safety and come to an arrangement with the insurance company. The best avenue would be contact the frame manufacturer and seek their advice/recommendation and use their assessment process. It is likely they have contacts for places than can test the frame for damage. The insurance company should be paying for any of this as the need for assessment is a direct result of the accident. Ideally you get a letter from the frame manufacturer stating what needs doing, and who should do it. They may even write that an assessment is uneconomic, and it is cheaper to replace the frame.

It is unreasonable for the insurance company to expect you to find someone to do the assessment if they are the ones insisting on it. If they insist the frame is not damaged, you have a right to ask for evidence of how they came to that decision. Make sure you have that information filed safely; it could be very useful for a personal injury lawyer in a few years.

  • 1
    Actually, I suspect it's not likely that the frame manufacturers will have contacts for testing. But you're right, the OP could contact them nevertheless to get their testimony as evidence. Or they could find a lawyer, who will know what sort of testimony the insurance adjuster would find convincing.
    – Weiwen Ng
    Commented Jun 2, 2023 at 18:49

Let's get this out of the way: IMO any carbon-fiber bike that's actually been run over by a car would probably require more testing than it's worth to make sure nothing is cracked - think "close-up x-rays of the whole thing, then ultrasound examination to be sure".

That being said...

What is the right approach to ask for what is needed?

The proper approach?

First, were you injured?


Let me repeat that:




The insurance company's goal here is to minimize their payout. Period. If that screws you over for life, they won't care.

Why shut up? Because even little things like responding, "I think I'm OK" to someone asking you how you are after you've been hit will be used against you. If you have been injured, hopefully you haven't said or signed anything that hurts you going forward.

(I've been there - and it's really interesting how things play out. Innocent little things you might say that you think help you can actually wind up being terribly damaging to your case. The defendant in my case is probably still wondering what she said in her deposition that sunk her defense faster than the Titanic. It was a simple 6-word sentence that she thought would help exonerate her, but it did the exact opposite.)

If you weren't injured, and it's an expensive bike you can't afford to replace, see the above about a lawyer.

If you can afford to take somewhat of a loss on replacing the bike, go without a lawyer. The insurance company probably won't try to screw you over too hard, because that would prompt you to get a lawyer and cost them a lot more money and time. Who knows, you might get lucky and they replace your bike pretty much with no questions asked.

And never forget your state's (assuming US) insurance commission or other oversight office usually has some way of filing complaints if you're not satisfied.

  • 2
    It makes me sad to think like this, but you're right. This is a battle between the injured party and the driver's insurer.
    – Criggie
    Commented Jun 2, 2023 at 4:22
  • That's a good point about injuries. Even soft tissue injuries could possibly count - the OP will benefit from someone on their side who's aggressive about counting the damage.
    – Weiwen Ng
    Commented Jun 2, 2023 at 18:48

Claim for it anyway

It's a reasonable assumption that the frame is damaged. It's not built to have the weight of a car on it. The insurance company just needs to spring for a whole new bike, in that case. It's a fixed cost.

Suppose they want you to salvage or repair parts of the bike instead. They absolutely can. However at that point you need to engage a bike repairer who's a specialist in carbon fibre repairs, you need to pay for microscopic testing of the frame, and you need to engage a lawyer to handle this, and every cent of this will be charged to them. It's an uncertain cost, and they may end up still having to spring for a whole new bike on top of that anyway.

No doubt they'll test your resolve to start with. But if you make it clear that you're sticking to your guns, this isn't a hill they'll be prepared to die on.


Financially, the resale value of your frame is now reduced. Who will knowingly buy a crash damaged frame? This is grounds for a replacement.

You can never be sure that a crack or other fault was not found, however thorough an inspection you get. So you'll always be nervous at speed, especially going downhill. The failure mode of carbon can be sudden and catastrophic. Don't let one accident become two.

The answers assume you are riding carbon. I ride steel which is probably more crash resistant, but I'd still look for a replacement. Why should I allow my possessions to be devalued without compensation?

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