Roaring Mouse Cycles Bike Fit

We’re proud to be a Retül Fit studio, the best way to make sure your bicycle fits your body.

Schedule Fit Now>>


Whether shredding the local trails with friends, winning the district criterium, attempting your 3rd Ironman (TM), or a casual commuter, we want you to be happy with how you feel and perform on your bike.

We're only satisfied when every rider achieves their desired riding experience.

Your time is valuable, and our fitters have busy schedules. Please note, we work by appointment only, and will charge a $100 non-refundable booking fee. This fee is credited toward the fit price.

Marissa in a USA jersey

Meet Your Fitters...

Marissa Axell

Marissa has been fitting humans to bikes for >10 years, holding both Certified SBCU Body Geometry and Retül Fit certifications.

She's CEO and owner of AXN Fitness and Coaching, a cycling coaching and personal training company. With an extensive background in fitness, she brings her biomechanics knowledge to help you feel one with your bike.

She's also a wine enthusiast, makes a mean burrito bowl, a category 1 competitive road cyclist and a Masters National Champ on the track!


Brendan Ekas

Brendan is an avid road cyclist who loves climbing and long days riding in Marin.  He enjoys helping others get the most out of the sport and to achieve their cycling specific performance goals. 

Brendan has a sports science degree and is a certified level 1 Retül fitter.  When not on his bike, Brendan enjoys listening to classical music and satisfying a taste for all forms of dark chocolate. 

Choose the fit that rolls with you 

Bike Fit Services

Schedule Fit>>

Aero/TT bike - Retul Fit

  • 3-3.5 hours
  • Because of the additional bike and aerobar configurations, this fit takes 30 minutes longer, and is billed as such.

  • pre-fit interview
  • physical assessment
  • three part fit assessment on MUVE
  • RETUL Vantage complete fit document with all your measurements
  • 1 follow up within 60 days

Retul Bike Fit

  • 2 - 3 hours

  • a pre-fit interview
  • physical assessment
  • three part MUVE bike fit assessment
  • RETUL Vantage with complete fit document with all your measurements
  • 1 follow-up session within 60 days.
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Complete Body Geometry Quick Fit

  • 1.5 - 2 hours
  • Includes:
  • a pre-fit interview
  • quick physical assessment
  • on-the-bike fit assessment
  • fit document with your measurements.
  • We will try up to 3 saddles. No camera or digital data are collected in this fit.
  • Does not include follow up fit.
Roaring Mouse Cycles Logo

Follow Up Fit

  • Follow up for all R.E.T.U.L. bike fits only.
  • We'll address any lingering issues or questions with the fit.
  • Use within 60 days of fit.