About Retül

Retül Bike Fit makes riding more enjoyable by making you more efficient while reducing the chance of injury and increasing comfort on the bike.


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Data Driven, Personally Crafted

Helping riders make decisions using data

  • A proper bike fit is essential for injury prevention and maximized efficiency
  • An optimal position on the bike will allow for greater comfort and enjoyment while riding
  • All bodies are different and your position on the bike should reflect your biomechanics.
  • A Retül 3D motion capture simultaneously measures three planes of movement on the rider as he or she is in motion.
  • Retül averages the rider’s pedal strokes to provide a comprehensive data set reflecting the rider’s movements.
  • Only at this point can a bike fit expert properly evaluate changes to a rider’s position.
  • Attempts to analyze the rider in a static position, or only in two dimensions, will not provide data at the same level of accuracy as 3-D motion capture.
  • If you are serious enough to clip into a bike, you will benefit from a bike fit.
  • Whether you are a professional or recreational rider, getting the proper bike fit is an effective yet economical way to improve performance.

_mg_9584-jpg_mg_4926-jpg_mg_5134-edit-jpgPhysio led 3D biomechanical bike fitting

Retül bike fit technology incorporates three main data points in fit theory:

1 | Bike Fits Must be Dynamic

  • Using motion capture technology, Retül records the rider’s positions in motion, therefore creating the most realistic picture of the rider’s actual pedal strokes and body positions when out on the road and trails.

2 | Measurements Must be Accurate

  • Measurements made by traditional tools are subject to human
  • error and therefore can be devastatingly inaccurate.
  • Slight inaccuracies can drastically change the rider’s feel after a ride.
  • The Retül system is accurate to within less than a millimeter, creating true objective data which can be utilized by the fitter for the perfect biomechanical fit.

3 | Biomechanics are Best Assessed in Three-Dimensional Space

  • Fit data collected in a traditional two-dimensional plane (i.e. video-based systems) is fairly limited because the fitter can only look at one view at a time, and those views stand
  • as independent reference points.
  • In order to make the best-fit recommendations, the fitter must realize that the front and side views are actually interdependent reference points.
  • In other words, the front and side views must be viewed simultaneously in three dimensions in order to see how all the applicable movements of the body are working together.

Retül uses a 3D motion sensor to simultaneously gather data on multiple angles of the rider.

So why choose HP3?

Tim is IBFI level 4 (the highest level of bike fit certification) and works primarily at Worsley Physio Clinic in Manchester, although pop-up clinics are held at our Preston clinic.

Previously Tim worked with John Dennis at PhysioHaus in Newcastle.  John is the most experienced Retul fitter in the UK who works directly for Retul to train all the other fitters in the UK and other parts of the globe.

Tim also worked with Phil Burt at British Cycling to assist with the retül measurements of the GB squad bikes. Phil is a leading authority on bike fitting with his book ‘Bike Fit – optimise your bike position for high performance and injury avoidance’.


As a physiotherapist with an experienced understanding of the biomechanics and rider assessment, the Retul system empowers the fitter to make the best fit decisions when it comes to making adjustments to a clients bike. The reasoning skills behind what adjustments are made are based upon interpretation of the data by the fitter. The system itself doesn’t tell the fitter what to do. A common mistake is that you will have the same fit and position whichever Retul fitter you decide to go to. This is not the case.

At HP3 we have a wide range of test saddles for you to try from Fizik, ISM, and SMP.  Being able to ‘try before you buy’ as part of the fitting process is a key component of finding the right set up and saving you money in the long run.



What does a Retül fit include?

The Retül fit process includes three components…

Before the rider is analyzed on the bike, a physiotherapy screen takes place that looks at the relative range of movement, flexibility and foot mechanics and structure. The findings are taken into consideration along with the dynamic fit data when individualizing a rider’s position. The client is then analyzed on the bike to obtain data on the position they are currently riding. Measurements are taken from both sides to look for any side-to-side differences not something that is possible through a static or 2-D assessment. The results are then used to make any necessary adjustments. Data is taken again to view the effect of the positional changes. The aim of any fit is to obtain the most comfortable and efficient position and consequently the most powerful.

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Need to know Retül fit questions…

How can a fit help or prevent injuries?

The fit session itself has several components to it. Each of these provides us with a picture of the individual’s biomechanical profile which then has to be applied to the fit and the position decided upon. A physiotherapy screening, an individual’s injury history along with biomechanics are taken into account during the process. Applying this information to the 3-D analysis ensures the best position for the rider. If you need ongoing injury management that can also be arranged through the clinic.

How long does a fit take?

On average, 2-3hours. Some fit
sessions are more complicated than others either caused by the riders injury history or simply by their pedaling mechanics and sometimes large functional asymmetries. In other words, the left and right sides can be very different!

What do I need to bring with me?

To the fitting session, you will need to bring with you your bicycle, a set of appropriate cycling shoes and a set of shorts and short-sleeved top (ideally tight fitting to prevent any unwanted movement of the LED markers).

What about LED placement?

The process is subjective but electrodes should be placed accurately to allow for reliable and valid data to be obtained. Our Lead Fitter is a Chartered Physiotherapist ensuring accurate and detailed knowledge of surface anatomy. This is a crucial part of the
Retül fit process. Bad marker placement = bad data = bad fit decisions.

Can I transfer my fit to another bike?

Each rider receives a document of their
results that include their individual range of movement taken during the fit and then using the ‘zin’ tool we accurately take measurements of the completed bike position. This allows the client to use the information taken to apply to another bike of the same type, similar geometry, and frame size. Alternatively, we can utilize the Zin tool
to digitally dial in a second bike.

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