bike sizing

We have integrated the FITKITTM  system into our process and also as a stand alone service.

The service provides the cyclist with greater certainty when purchasing a new bike or frame.

The aim is to aid riders in the choice of frame size and geometry for both road and cross-country mountain bikes, this is not suitable for TT or Triathlon style bikes.

Bike Sizing is a process to determine the parameters of a suitable frame size and geometry to accommodate the rider in a position that ideally:

  • Is bio-mechanically safe
  • Comfortable, given the riders physical mobility and stability
  • Does not adversely affect the control and handling of the bicycle
  • Allows for fine tuning of the seat and handlebar position to optimize comfort, efficiency and performance. i.e. the contact points are not at the “end of range”

Each rider will be interviewed to ascertain their individual needs for their new bike.

A basic physical examination will then take place, together with the taking of a series of body measurements that are then used to calculate the measurements for top-tube and stem combination, seat tube length and saddle height. The calculations use a system that has evolved over the last 30 years.

Each Rider is provided with a report showing these key measurements to help in choosing their next bike or frame. For ease, the key measurements are illustrated as below.

Saddle Height

Using this method has advantages and disadvantages.

By using the FITKITTM Systems measuring tools and software and the anatomical proportions obtained from body measurements.

  • Bike recommendations are usually expressed as top tube and stem length, together with predicted and initial set up guidelines for seat height and seat to bar drop.


  • Simple, quick, effective, low cost to the cyclist.Frame
  • Far superior in projecting a frame size than using a rider’s height or stand over clearance, or an ‘eye’ guestimate.


  • Not seeing the cyclist ride.
  • Not predicting a final fit position before selecting a frame size and component mix.
  • Not taking into account mechanical asymmetries, instabilities or weaknesses that may be seen on dynamic assessment either on or off the bike.

Bike Length

The FITKITTM System of sizing uses anatomical proportions (body measurements), modified by responses to a simple rider interview. The recommendations that come out of the proprietary data set embedded in the digital sizing calculator are derived from extensive measurement of real riders on real bikes.

The cost for the assessment is £45 and comes with a 10% discount for a Retul Bike Fit at fit-me-up, if booked within 4 months of the sizing appointment.

As we don’t sell bikes here, this opens you up to the whole bike market to check which bikes and frames are most suitable for your needs.

Any questions? Please contact Dean

Or to book please click here

We look forward to assisting you.

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