Analysis: Missing data will be evaluated for pattern of missingness for each psychosocial variable and behaviour at all time points using the dummy coding procedures. Depending on the outcome of these tests (e.g., missing at random, missing completely at random, etc.) we will initiate the appropriate missing data handling strategy. ITT analyses will also be performed in addition to sensitivity analysis procedures. A 2 (condition) x 3 (time) repeated measures factorial ANOVA on the primary outcome of child adherence to the bikes. A child from each household in the eligibility range will serve for this analysis (chosen through randomization procedures). Post hoc examinations using Tukey follow-up procedures will be utilized if necessary. Cluster analysis/HLM will be used for parent/child collinearity if needed. The qualitative analyses will incorporate the accuracy, thematic analysis, and coding.