Meet Sean O'Neill our bike fitter

Sean O’Neill is the owner and fitter at Precision Bike Fits. he has been fitting triathletes and cyclists since 2015. He’s built his first bike at age 14, and has been infatuated with bikes since. Sean earned a degree in mechanical engineering from the University of Colorado at Boulder in 2004, where his interest in cycling expanded while volunteering in Allen Lim’s integrated physiology lab. After graduation, Sean worked as a medical device design engineer for nine years, when finally he decided to take the leap into the cycling industry. In 2013, Sean joined SRAM as a design engineer in San Luis Obispo, California, and never looked back. In 2015 he attended the Fit Institute Slowtwitch (F.I.S.T.), where he was trained and certified as a fitter by Dan Empfield (, Ian Murray (LA Tri Club) and Paul Swift (, and he’s been fitting cyclists of all types ever since. In 2017, Sean moved to Kirkland with his wife and two dogs, where he continues to work for SRAM as an engineering educator.


Education and Credentials:

·        University of Colorado at Boulder - B.S. Mechanical Engineering

· - Fit Institute Slowtwitch (F.I.S.T) professional fitter

Sean continues to enjoy cycling in all aspects, and also enjoys time spent outside with his family and friends.

To contact Sean, please email him at:

Sean's approach and philosophy can be summed up in a few words:

  • If you’ve ever purchased a bike, it is unlikely that you selected any of the components on it. You purchased that bike “as-is”, and were sent on your way pedaling down the road with little more adjusted than the saddle height. Bicycles are rigid, symmetric machines that require some amount of rider accommodation. Too much accommodation can significantly reduce your efficiency on the bike, and more importantly, it can lead to injury. If you’ve ever ridden 100 miles on a bike, each of your pedals was turned between 27,000 and 48,000 times. This amount of repetitive use demands that human accommodation be minimized. This is avoidable with the application of a thorough bike fit.

  • Most people think that a bike fit is a one-time, permanent solution…it’s not. As athletes adapt to exercise, new equipment, new positions, etc., their fit will likely need to be adjusted.

  • Triathletes and TT riders are the most at-risk for bicycle related repetitive use injuries, given the distances ridden, riding position, and number of points of contact with the bike. They have the most to gain from a bike fit.

  • Every athlete is different, with different goals and constraints. This means that every fit is unique, with different potential solutions. There is usually more than one solution that will work for an athlete on their bike. Some solutions may not be possible through adjustment, and may require different equipment.

  • Most bike fitters are employed by retail shops that also sell components. While this can be convenient, I choose not to sell parts, to avoid any potential conflicts of interest. I am only interested in fitting you to your bike. Again, I want to make you as efficient on the bicycle as you can be, with your personal goals and physical challenges in mind.

  • I strive to make getting a bike fit a fun and educational experience for the athlete.

  • I have intimate knowledge of cycling components and drive-train designs, which is fairly unique and also beneficial. I bring this knowledge to my fitting practice, which educates the athlete and benefits the fit itself.

  • I set honest and realistic expectations and communicate them as transparently as possible.

  • I communicate my goals and intentions to the athlete during their fit, and explain what I’m doing and why I’m doing it.

  • I am not a physical therapist…in fact, I’m more of a bicycle therapist. I will never opt for increased aerodynamics or aesthetics over comfort and efficiency. I require that athletes be as honest as possible about their comfort on the bike,both in the fit and during the post-fit validation period. I may notice things during a fit that I’ll recommend be addressed by a medical professional.

Marques Garcia, IRONMAN Certified Coach.

Triathlon Coach Seattle Bellevue Redmond Kirkland Issaquah Sammamish