The sudden failure of bicycle parts is an unexpected cause of cycling accidents. Injury claims arising require a focussed approach which Cycle SOS is providing with greater frequency.

Do not think you cannot make a claim for injuries sustained by something failing on your bike even if it may appear to be out of warranty. We’d always suggest you contact us for free initial independent advice.  Even if a claim is unlikely to be viable we have a data-base of repair specialists including carbon fibre.

If you have been involved in a cycling accident which you believe was caused by component failure, our helpline team are here to assist you. The first thing they’ll say is ‘don’t part with failed component’ (even if you have taken images of it).

If you have been in touch with the manufacturer/store directly it is likely that they will have asked you to return the bike or faulty part in to be examined. We recommend you hold onto that as evidence in your claim. 


We are fortunate to have some of the best contacts in the business to make a forensic assessment of a potentially defective part. We work with academic experts from UK universities and specialist assessors in the components industry to ensure the reason for failure is accurately identified. This means that the strongest possible case can be prepared on your behalf.

What Causes Bike Component Failure? 

A bicycle relies upon the interaction of many different parts and components to operate safely and efficiently. Should any one of these parts fail while in use, it could lead to loss of control and a crash. A sudden involuntary swerve or dismount can lead to complications in a group ride, on a track or in busy traffic.

The failure of components can be variously  attributed to design, manufacture, assembly, maintenance and use issues.  Unfortunately, we see component failures from some  well-respected  brands as well as the budget end of the market.

Careless fitting or inadequate problem diagnosis   by professional bicycle mechanics or store staff may also be responsible. However, all cyclists have an obligation to themselves to undertake certain basic checks before every ride, to undertake routine maintenance and to react to any change in a cycle’s characteristics or unusual noises!


Sudden and involuntary contact with the planet is almost always going to hurt. Sometimes the young and/or fit appear to bounce back; we’ve all from time to time picked ourselves up with due thanks to whatever protective kit we were wearing. 

But even a fall onto grass can cause fractures; a lamination issue in a carbon fork threw one client onto a sports field with humeral fractures.

A fork drop-out which did exactly that deposited another client onto the tarmac and into theatre for a replacement shoulder.

For another client, a broken chain sadly resulted in a concussive brain injury with cognitive issues.

Unlike the tragic recent case in which the rider of an e-scooter was killed by falling under a truck, we’ve fortunately not seen a component failure cause such an awful event, but the principle is the same. The e-scooter had very under inflated tyres, so when it struck a modest highway irregularity, control was lost. 


Our experienced team are themselves cyclists, some of whom have built their own machines, so know the difference between a headset
and a bottom bracket.  Others are also trained in accident investigation and reconstruction techniques, headed by a former Sergeant from the local Crash Investigation Unit.

We are members of the Law Society’s Personal Injury Panel and Headway, the charity for the victims of ABI and their carers. One of us has a particular empathy with the clients as his own implants trigger airport security scanners.

In addition we also have a network of specialists who conduct forensic investigation and analysis on behalf of our clients to strengthen their claim and assist us in assessing and their case.  

Over the past 30+ years, our team have taken on some of the biggest opponents in complex cases, successfully recovering large sums of compensation where other firms have turned them away.

When claiming for compensation, we will always take into consideration all consequences of the accident. In addition to obtaining damages
for the injuries sustained, we will also include compensation for past and any future loss of earnings, medical treatment, care and assistance, and damage to the bike and kit.

In the past, our team have been involved in supporting many initiatives to improve cycling safety. Most notably, members of our team previously worked with Cycling England, the Cycling Demonstration Town project and various cycle city expos. The opinion of Consultant Solicitor Paul Darlington has also featured on BBC Radio current affairs.


We’ve compiled a gallery of defective components we have photographed as part of real ongoing or concluded cases:

Whilst the individual circumstances of every claim are different, we do see trends in the ultimate cause of the failure in a case involving defective components. This is by no means an exhaustive list – we have included the brief details of recent failures we have assessed so that you can use it as a reference against your own accident. Many clients have little confidence that they will be able to pursue a claim when they first make an enquiry, but drawing on 30+ years of experience in this type of claim, we can more often than not find a way forward to pursue a claim on your behalf.

Recent failures we have evaluated include:

  • Spontaneously fractured fork on a new mountain bike delivered 3 months prior to the accident.
  • Corroded and snapped crank axle on a bike purchased a year before.
  • Broken pedal axle on a new mountain bike purchased less than 6 weeks prior to accident.
  • Newly purchased bike chain which spontaneously snapped.

While failures of the steerer, forks and cranks are most likely to result in immediate loss of control, they are not the only parts on a bike which can cause problems.

Something as seemingly harmless as a mudguard stay, if fitted without proper care and thought, is capable of causing an accident. Should the head of bolt securing the stay to the guard catch in the tread of the rotating tyre, a plastic guard is likely to telescope and jam between the crown of the fork and the tyre; the most abrupt emergency stop and a close encounter with the road ahead. It’s happened, because a shop fitted aftermarket guards which were slightly too narrow for the tyre and led to complex maxillo-facial injuries. 


Under no circumstances part with the component until you have taken advice. In the event of component failure, it is important to ensure the faulty part is forensically examined. Cycle SOS can help with this as part of your claim. The failure should be photographed and recorded in a forensic report before considering returning it to the manufacturer/supplier.

To check if you may be able to pursue claim for an injury caused by bicycle component failure, call us for a free initial assessment on 0808 100 9995 and talk to our specialist legal team. Our helpline is available 24/7 without charge or obligation.