Thailand’s market for “big bikes”, or motorbikes larger than 400cc, has been enjoying tremendous growth especially with their attractive design and powerful engines, big bikes are a dream machine for many men and even some women. According to the Land Transport Department, nearly 165,000 big bikes have been registered in Thailand so far, and the number is expected to near the 200,000 mark by the end of this year (2021). On a global scale, the market for motorcycles is concentrated in the countries of the Asia-Pacific region, an area that accounts for 80% of total annual global sales (source: Statista). Therefore, competition has been fierce and all brands are looking for ways to increase brand loyalty in order to stabilize their earnings and sustain sales growth over time. Therefore, it would be beneficial to all these big bike brands to understand what constitute consumer loyalty. The purpose of this research is study of factors influencing brand loyalty of big bikers in Thailand. These factors include First-order variables: Customer Expectation (CE), Customer Satisfaction (CS), Brand Personality (BP), Brand Image (BI), Brand Trust (BT), Product (PD), Customer Psychology (CP); and Second-order variables: Customer factor (CUS), Brand factor (BRA). 400 sample were collected using electronic questionnaire through social media. We used second-order Structural Equation Models (SEM) for data analysis. The result shows that the RMSEA, which is an absolute fit index that assesses how far our hypothesized model is from a perfect model, for this model is .047 (<.05) which strongly indicates a “close fit” and the Goodness of Fit Index (GFI) value is .903 (>.90), the model seems to fit well according to the descriptive measures of fit. Moreover, CFI, which is incremental fit indices that compare the fit of our hypothesized model with that of a baseline model (i.e., a model with the worst fit), its value equals .900 indicating an acceptable fit. More importantly, Customer factor (CUS), which is second-order factor of Customer Expectation (CE) and Customer Satisfaction (CS), seem to have significant effects on Customer Psychology towards Brand Loyalty of Big Bikers in Bangkok Thailand due to their p-values are all less than .05. That means if big bike companies and manufacturers can come up with the models that meet or exceed consumer expectation and satisfy customer needs, big bikers will be more likely to switch to your brand and become brand loyal any day.