How Momentum Engineering Corp. used enDAQ to fill a gap in bicycle crash research

Momentum Engineering Corp. (MEC) identified a lack of comprehensive data surrounding bicycle braking performance. Without reliable, bike-type-specific deceleration data, accident reconstructionists were forced to apply road bicycle figures to BMX or other bicycle crashes—producing inaccurate results. MEC used an enDAQ sensor to conduct controlled brake-to-stop tests across eight different bicycles and publish peer-reviewed findings..

A critical gap in bicycle crash research data

Nick Famiglietti and his colleagues at Momentum Engineering Corp., a consulting firm specializing in accident reconstruction, identified a significant gap in research surrounding bicycle crashes. As Famiglietti noted, there was not a lot of strong data about bicycle braking.

An accident reconstruction firm may encounter a BMX bicycle crash case but only have data from a road bicycle—providing an incomplete and potentially inaccurate picture of the crash. To accurately determine how fast a bicyclist was traveling at the time of an incident, MEC needed comprehensive braking data across a range of bicycle types.

• No comprehensive data existed for bicycle braking across different bike designs and applications.
• Applying road bicycle data to BMX or other crash types yielded inaccurate reconstruction results.
• A portable, lightweight sensor was required that would not alter the center of gravity of the test bicycle.
• Data needed to be suitable for publication in a peer-reviewed industry journal to support legal testimony.

Controlled multi-bike brake testing with an enDAQ sensor

MEC used an enDAQ sensor (S4-E25D40) that satisfies the SAE-J211 standard for vehicle impact testing sensors. The sensor was secured to the top tube of the bicycle frame between the seat and the handlebars—a position that minimized weight addition and had no meaningful effect on center of gravity.

Over three days, MEC conducted three test sessions at different sampling rates: 3,200 Hz on day one, 100 Hz on day two, and 800 Hz on day three. Each test measured the deceleration across two phases: the initial braking phase (lever squeeze and onset of deceleration) and the incipient lock-up phase (skidmark production).

Video was also used to document each brake test. By programming UTC timing on the sensor, the timestamped data was synchronized with the video footage for a thorough and reproducible analysis.

• Eight different bicycles tested with a single rider at the same location for consistent conditions.
• enDAQ sensor begins recording with a push of a button—no laptop connection required per trial.
• UTC-synchronized timestamps enabled accurate video-data fusion for analysis.
• SAE-J211 compliance ensured data was accepted for peer-reviewed publication.
  
  

Quantified braking data published in SAE International

Using the enDAQ sensor, MEC quantified deceleration rates for bikes using rear-only braking and those using both front and rear braking. The 16g DC-response accelerometer captured significant vibration data alongside the deceleration signal. By applying a 1 Hz 6th-order Butterworth low-pass filter in enDAQ Analyzer software, the team isolated only the braking deceleration of interest.

The results demonstrated clear differences between the two brake configurations, with combined front-and-rear braking producing substantially higher steady-state deceleration magnitudes than rear-only braking.

Famiglietti and his team published their findings as a technical paper in SAE International. This peer-reviewed data now allows Momentum Engineering Corp. to provide reliable, defensible legal opinions in cases involving bicycle crashes—across any bike type covered by the study.