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The basis of a good bike fit is to increase physical performance. Performance increases when disfunction decreases.

Disfunction is caused by poor physical condition and bad positioning. Bad positioning creates an environment which challenges the body, forcing it to counteract and adjust, leading to disfunction.

At FORM the aim is to liberate the body and allow it to perform in it's natural state, free of disfunction.



If you're in the market for a new bike, choosing the right frame is paramount to achieve the correct position.

FORM's bike sizing & advice service offers a fresh, unique and modern perspective on frame sizing and gives clarity on the relationship between your own proportions and the shape of your ideal bike.

A sizing session will give you all the info you need to find the most appropriate bike. This includes a basic bike position as well as the ideal frame geometry you should be looking for.

The sizing & advice service encompass all brands and is completely impartial.


Each discipline of riding has it's own specific criteria. Each individual within that discipline has their own unique needs.

Whether you're an amateur sportive rider, hardcore ironman racer or short course TT rider, having a position which enables you to function optimally is equally important.

FORM's approach to fitting is both specific and adaptive - specific to discipline and adaptive to the individual and their circumstance.

A FORM fit is designed to give you the physical tools to perform at your best, and to create the perfect balance between energy output, power and momentum.


If you intend on purchasing a bespoke, custom-geometry frame from a builder, this service is worth considering.

Most frame builders are not bikefitters, so achieving the correct geometry for your own riding style and physiology can be a hit and miss process. To avoid this it's imperative you enter the ordering process with sufficient knowledge of what you want, and what you need.

The FORM fit-to-design process provides knowledge on how your riding position informs the frame's geometry. A custom frame should last a lifetime, and any mistakes made at the beginning of the process are irreversible. Going through this invaluable process will provide one or more of the following things:

  • Advice on how to enter discussions with the relevant frame builder / what to ask for, what to look out for
  • A pre-purchase CAD mock-up design of the frame based on your fit measurements to compare with the builder's own design
  • A full CAD frame design, based on bike fit numbers, to hand over to your chosen builder
  • A service including initial frame design, communication with the frame builder, changes and final design


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Form is an independent, customer-centric bike fit studio in the London area.

The focus of the studio is solely on bike fitting and on providing impartial advice on bikes and equipment to clients. Form is not a retailer.

The studio is run by myself, Ronan Descy, and is based on a functional, non-branded fit process, the end result of a decade of fitting in a number of high-profile London outlets using other, well-known branded methods.

I am impartial to everything except result, and my focus will always be on the individual.

In an industry drowning in technology and hype, my aim is to find effective, real-life solutions and provide you with useful, informed knowledge on positioning, technique and bike sizing.


Book a fit or sizing session with Form and you will be guaranteed the following:

  • An uninterrupted, friendly, one on one session in a private setting
  • A process which informs you and provides you with the info you require
  • Clarity on the relationship between yourself, your position and your bike geometry
  • Impartial and honest advice on all brands of bikes and equipment
  • A free follow up if changes are required post fit
  • Freedom to correspond by email at any point to discuss anything else which comes up