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A bicycle and e-scooter expert decides how a crash happened on two small wheels and whether the machine, the road or the rider's conduct was the cause: why a fork snapped, a brake failed, a battery burned or a wheel caught a seam in the pavement. These cases differ from car crashes because a rider has no restraint, very little data is recorded, and a small surface defect can be decisive. This page covers bicycles, e-bikes and e-scooters. A general crash reconstruction belongs to an accident reconstructionist, a motorcycle case belongs to a motorcycle expert, and a head injury's mechanism belongs to a biomechanical engineer.
The expert reads police reports, site photographs and measurements, the bicycle or scooter itself, app and rental data, purchase and repair records, and any video. Preserving the device matters most, and it should not be ridden, repaired or stripped of its battery before a joint inspection.
Bicycles have a dedicated federal rule. Part 1512 sets requirements for bicycles, other than track and one-of-a-kind bicycles 1. It covers items such as brakes, and for quick-release devices it says the levers must be clearly visible to the rider and show whether they are locked 1. Footbrake bicycles have a stated stopping distance test, no greater than 15 feet from the set test speed 1. A compliance record is therefore available to check, though it shows how a design tested rather than how this unit was built or maintained.
Electric bikes were folded into that rule by statute. A low-speed electric bicycle is a two- or three-wheeled vehicle with fully operable pedals and an electric motor of less than 750 watts, with a top speed under motor power of less than 20 mph for a 170-pound rider 2. Those bicycles are consumer products subject to Part 1512 2. That definition sets where the CPSC rule applies. It does not by itself decide how a state regulates the vehicle on the road, and a device that exceeds it raises different questions. Standing e-scooters are outside this definition because they have no pedals, so an expert has to look for whatever other rule or voluntary standard applies.
Helmets have their own rule. The federal standard describes test methods and minimum performance criteria for all bicycle helmets 4. A dispute over whether a helmet was certified or fitted can affect both the injury and the comparative fault argument, depending on state law.
Injury data supports the scale of this field. CPSC staff report 533 micromobility fatalities from 2017 through 2024, rising from 5 in 2017 to 135 in 2024, and an estimated total of 698,500 emergency department visits 3. Of the 310 e-bike fatalities and 206 e-scooter fatalities, motor vehicle accidents and control issues were the top hazards, and lithium-ion battery fires were linked to some deaths in each group 3. CPSC also warns that its later data is likely incomplete, and staff considers its incident data anecdotal and not nationally representative 3. So those counts should be used with that caution, and never as a rate.
For bicyclists on public roads, NHTSA counted 1,103 pedalcyclist fatalities in 2024, down 6 percent from 1,173 in 2023 5. Since 2022 that count includes riders on bicycles powered by pedals, motors or both, and it covers only crashes involving motor vehicles in transport 5. Its definitions differ from CPSC's, so an expert should not add the two together.
Three questions usually decide these cases. Did the product fail, or did the crash break it? Metallurgy and fracture patterns answer that, and the sequence matters, since a broken frame may be a result. Did the rider have a chance to respond to a pavement defect? Speed, sight lines and how a small wheel behaves at an edge matter here. And did assembly, service or a rental operator's maintenance cause the problem? Shop records and fleet logs may show that. Battery fires raise separate fire cause and product questions.
Look for a mechanical or bicycle engineer who has tested bicycles or micromobility devices, or a reconstructionist with direct experience in this type of crash. Experienced bicycle mechanics can speak to assembly and service. Some cases need a metallurgist and a fire investigator as well. No single board certifies this field, so ask about testing and exemplar work.
CPSC staff report 533 micromobility fatalities from 2017 through 2024, rising from 5 in 2017 to 135 in 2024, and warn that the later years are likely incomplete.
Case Types
Frame, fork and handlebar failures
Brake and quick-release failures
E-bike and e-scooter battery fires
Rental e-scooter maintenance and fleet claims
Pavement seams, potholes and roadway hazards to riders
Collisions between riders and motor vehicles
Negligent bicycle assembly and repair
Helmet certification and fit disputes
Qualifications
Related Specialties
FAQ
Look for a mechanical engineer or reconstructionist who has tested bicycles or micromobility devices and worked on this type of crash. Experienced bicycle mechanics can address assembly and service. No single board certifies the field, so ask about testing, exemplar work and direct experience with the type of device.
A two- or three-wheeled vehicle with fully operable pedals and an electric motor of less than 750 watts, whose top speed on motor power alone is less than 20 mph for a 170-pound rider. Those bicycles are consumer products subject to 16 CFR Part 1512. State rules for road use vary.
The statute's definition reaches vehicles with fully operable pedals, so a standing e-scooter without pedals falls outside it. An expert should identify which voluntary standard, state rule or contract applies to that device. Whether a product is defective is a separate question from whether a rule applies.
No. It should be preserved as it is, with its battery and any data, until all parties can inspect it. Repairs or even routine handling can erase fracture surfaces or wear marks. For rentals, the fleet operator's maintenance and trip records should be requested promptly.
A reconstructionist addresses speed, position and sequence in a crash. A bicycle or scooter expert adds the behavior of the device: frame failure, brakes, wheel dynamics and how a small wheel handles a surface defect. Some experts do both, and complex cases may need each.
In general, bicycle and e-scooter expert fees are determined by the expert themselves, based on a variety of criteria. Among those criteria are engineering credentials, testing experience, inspection needs and the volume of records to review. Vident does have some influence over expert fees by comparing experts within a specialty, but ultimately it is a personal decision by the expert.
Sources
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