As sex differences are very pronounced in motorcycle crashes, both in terms of number and severity, the present study aims to determine the relationship between gender, motives for riding a motorcycle, and risk-taking behaviors among motorcyclists. Declared aberrant behaviors, conformity to gender stereotypes and motives to ride a motorcycle were investigated among 2,262 riders of heavy motorcycles, through an Internet survey. Ages ranged from 18 to 78 years, 10.5% of the respondents were women. Results revealed the new scale on motives for riding a motorcycle was effective and allowed to show that competition motives were associated to masculinity, low femininity and youth. They also showed that maleness, masculinity, youth and competition motives were predictors of violations and femaleness and low masculinity were predictors of lapses. Furthermore, competition motives were also mediators between masculinity and aberrant behaviors, except for personal protective equipment negligence. This study gives new knowledge on the relationship between conformity to gender stereotypes, motivations and the behaviors of riders of heavy motorcycles. Results can be useful for adapting prevention campaigns to the small sub-groups that are the more at risk in the motorcyclists' population.