Effects of Assistance Level and Familiarization on Elderly Riding a Balance Assist Bicycle

Abstract

Cycling accidents among older adults caused by a loss of balance are a safety concern, particularly at low speeds where bicycles are inherently less stable. A Balance Assist system, which provide additional steering torque to support the rider, have been proposed as a way to improve stability and confidence for elderly cyclists. However, it remains unclear how different levels of assistance affect riding behavior and perceived comfort, and whether riders adapt to the system with repeated use.

This thesis investigated how different balance assist levels (High, Low, None) affect motion variability and perceived comfort, and whether repeated use across three trials leads to familiarization, reflected in reduced motion variability and increased comfort. Thirty-one older participants rode an instrumented TU Delft Balance Assist Bicycle, a bicycle developed in collaboration with Royal Dutch Gazelle and Bosch eBike Systems, without prior knowledge of the assistance system. They rode around a fixed course under one of the three balance assistance levels. Steering and roll behavior were recorded using sensors on the bike, and perceived comfort was measured using a questionnaire administered after each trial.

The results showed that balance assistance levels influenced riding behavior in a context-dependent way rather than through a general, uniform effect. In particular, higher balance assistance levels were associated with increased roll variability specifically in curved sections, while steering variability was primarily driven by riding speed and segment type rather than by the assistance level itself. Perceived comfort improved significantly across trials for all gain conditions, indicating that riders became more familiar with the bicycle over time regardless of the level of assistance received. However, this subjective improvement was not accompanied by significant changes in objective riding behavior, suggesting that familiarization occurred at the level of perceived comfort without corresponding measurable changes in motion variability.

These findings suggest that balance assist systems do not simply reduce motion variability across the board, but instead interact with specific riding contexts such as cornering in ways that require further investigation. The observed dissociation between subjective and objective adaptation highlights the importance of considering both perceived and measured outcomes when evaluating assistive cycling technologies for older adults. Future research involving longer-term use, system activation verification, and within-subject designs is recommended to better understand how balance assistance can be optimized to support safe and comfortable cycling in this population.