Our technology goal is to keep assembling and developing the most accurate, effective and sophisticated bike fitting equipment. We keep building a technologically advanced foundation to our bike fitting protocols, so we can make the most advanced bike fitting methodology available to everyone.

Whenever the commercially available technology is not to our specs or not advanced enough for our needs, we invent it - opening new frontiers to the realm of possibilities in bike fitting. Some of our proprietary technologies are already in version 3.x of development - and keep going.

In our quest for excellence, we succeeded to create an environment so advanced that it rivals and exceeds the technology available to the most successful Pro teams. We created a nugget of bike fitting state-of-the-art technology, know-how and quality of service to support you - right here in South Florida .


We use Retül 3D dynamic motion-capture simply because it's the best (and the only true) 3D dynamic motion capture system. Nothing else is quite like it. That's why we chose it.

When we were faced with the decision to choose a fitting system, we looked for a system that would be truly beneficial to our customers.

We don't think Retül is the best because we have it. We have it because it is the best.

It's a big decision to be a Retül Certified Bike Fitting Center. It takes a lot of education through Retül University and a lot of training to become and stay Retül Certified. The recurrent annual recertification process is very demanding and designed to assure only the best centers who maintain the highest bike fitting standards can maintain the prestigious Retül Certification.

Retül is not an inexpensive technology either. It's a huge financial commitment. Just a few years ago, only large and well-funded Pro Teams could afford to own a Retül system. In 2004 the cost of fitting with this level of technology was as much as $1,500 per rider! 


But as the pricing of this technology has become more affordable, we have been able to bring it to the everyday cyclist and make it affordable for everyone to get properly fit.


Retül separates fitters from the rest and sets up a solid base for the success of your bike fit. That's why it's the standard fitting system for powerhouse Pro Teams like Sky, Europcar, Garmin, Team Colombia, etc.

But most importantly, Retül is a system that is blind to your status as a rider. It fits the every day cyclist just as well as it does the Pros. Actually, Retül probably is more valuable to the average cyclist, because it's able to help with the typical issues cyclists encounter when they don't have a complement of doctors and physical therapists at their disposal for personal care.





Retül it the only live 3D motion capture analysis tool in existence. Other systems are either static fit (AKA Old School)  or may claim to be motion capture, but they really are stop-motion capture.

What's the difference?


The key difference in comparing a static fit technology versus motion capture is in the quality, quantity and accuracy of the bike fit data points acquired.

In static fit and stop-motion capture systems, the measurements of a rider interactions with the bike are taken in a static position using a plumb line, a protractor, a laser plumb line or a camera. The rider is asked to pedal and then to stop at a predetermined position. This is done either physically stopping the rider mid pedal stroke or by pausing a video. The shortcoming of this methodology is:

  1. Rider is measured while stopped. The simple act of stopping a rider introduces large errors. When the rider is asked to stop pedaling, the position will never be accurate: if the rider shifts or changes position just a little (often riders slightly adjust because can't keep perfectly still), the measurement is severely tainted. Even with high-speed cameras, the act of pausing playback causes video contrails that make accurate measurements impossible. Often, the measurement error is larger than the fit range allowable for the rider, making this methodology limited at its best.

  2. Rider is measured at a pre-determined location. Who is to say that's the right position? For example, the leg extension is measured at the bottom of the pedal stroke. Seems plausible, right? With Retül motion capture analysis we learned that is not true. Often the maximum extension happens at some angle of revolution either before or after the bottom, depending on the pedal ID of the rider (ex: toe down or heel down). This introduces a huge bias into the measurement and makes the results of stop-motion capture limited in scope and application as they are non-authentic of the actual cyclist's motion.

  3. Rider is measured in 2D. There is no depth to the bike fit measurements, no ability to observe the complex interactions of the body with itself and the bike- which happen in 3 dimension (for example, knee movement). This severely limits the ability to diagnose and correct out of plane movements, which are always found in cyclists with unhealthy motions that lead (or will lead) to repetitive use injuries.

This is not to say there aren't benefits from using this methodology. We still use it for our basic fit protocol for our entry-level, basic riders with acceptable results.

However, clearly, this is not the protocol to use for advanced fitting, performance gains and, positively, this protocol cannot address Fit For Injuries.







In static and stop-motion bike fitting, the cyclist is stopped at a specific location and a measurement is taken. This may not be the correct location









The measurements are subjective in location and are vulnerable to the cyclist's small adjustments while stopped. This introduces large errors


Retül measures a rider in 3D in real time, without stopping and during targeted levels of exertion.

3D means that the system sees movements in all 3 planes simultaneously (X, Y, Z), not just from the side like in 2D systems.

Retül also calculates the key angles of flexion and extension without imposing any arbitrary measurement location. By collecting 16 data points per second from its 8 sensors, Retül collects close to 4,000 body location sets per data capture as they happen in real time.

It then calculates several max and min and position measurements based on those 4,000 body-set data points. Regardless of where it occurred, Retül finds the max and min of the rider's range. So, if a rider pedals toe down and reaches max extension at 170 deg of pedal revolution instead if 180 deg, Retül is there to see it and provide us with that key information. This prevents making big mistakes and over or under-extending a rider's stroke. If the knee wavers from side to side, Retül captures its tracking and gives us the vital information to correct it.

This is genius.

Retül worries about finding what happens, not where it thinks it should happen. And by doing this, we can accurately fit you for the way you actually move with your bike and achieve the best performance and comfort.

Also, the 3D measurements give us the ability to see unhealthy motions as they happen. We can track vital movements such as the knee tracing and your foot floating side-to-side in real time, in 3 dimensions. This empowers us to make the changes that keep you healthy, strong and efficient.

We could go on forever to share with you what the Retül system does and how it does it. But what matters is what it allows us to do. Retül is the tool that helps us make the difference in a rider's bike fit and longevity.

The best way to understand the depth of the abilities of this technology is to come and experience it yourself.

Retül 3D motion capture allows us to see movements in fine details, like seen here for the knee and foot/ankle motion


We also use RacerMate Computrainer Ergometer tools. Computrainer has been at the leading edge of power testing and pedaling mechanics analytics technology for decades and it's still the reference tool for everyone in the industry. If a power study has been done, Computrainer was the tool of the labs, universities, physiologists and athletes involved in ground-breaking pedaling research.

The Computrainer's unsurpassed accuracy in reading power (it's the benchmark against which other power meters are tested) and its unique ability to break down the pedal stroke torque in small increments of pedal revolution gives us the analytic tools to make you a better, more powerful and more efficient cyclist.

The Computrainer allows us to study your unique pedaling style, your Pedal ID. Mashers are quite different than spinners. Rider who pedal heel down have a different relationship with their bike fit than those who pedal toe down. This is important as the Pedal ID gives us a target for your bike fit range.  Each rider benefits from a specific bike fit position within this range to maximize his/her unique pedaling style.

Also, for pre-fit and post-fit power and torque distribution analytics, the Computrainer is a great check point to see the actual improvements achieved with the Retül system. The systems are complementary and build upon each other's strengths.

Essentially, the Computrainer allows us the see the most truthful, raw data of a rider's relationship with the bike: the power output at the wheel.

Thanks to the Computrainer and our expertise, you'll know your fit is successful and will be able to quantify the gains .


The Computrainer Pedal ID analysis helps us break down your pedal stroke in its elements and fit you better. Here we see the Power and Torque diagram.










Power analytics quantify your before and after fit performance


We saw the full potential of the Retül and Computrainer technologies and we sought to make them work together and extract the maximum performance possible.

We developed our own tools to complement these two key technologies. We developed a very advanced system to simulate riding conditions with as much fidelity as possible. Our own original design and manufacturing of this rig allows us to hold the bike and rider in a stable position when under heavy loads. We affectionately named it the Fit Rig.

The role of the fit rig is very important: Retül measures the cyclist's body postures to within 1mm of accuracy. With this level of accuracy, extraneous data and data noise must be filtered out for the collected data to be actionable. We must measure the organic movement of the rider on the bike, not the bike moving around.  This is a requirment that your typical trainer's front wheel-block can't provide: it slides around too much. The fit rig, on the other hand, provides a noise-free data platform with high fidelity to riding conditions.

Since Retül motion captures must be done at high power levels to be significant, the stability of the fit rig under high loads is critical. We tested the system up to 1,000 Watts of power output without a hint of a movement. For out-of-the-saddle data capture for climbing and track sprinting bike fit protocols, the fit rig is the only platform you can trust.

Additionally, from an operating accuracy point of view, Retül relies on a perfect horizon - blindly. It means that the bike has to be perfectly level axle-to-axle. Retül calculates angles to plumb and a non-leveled bicycle would return data that's incorrect and non-actionable - we call it garbage data.

Our rig assures the quality of data by being perfectly plum by design and thanks to an array of calibration tools. It suspends the bike from its axles, normalizing it to the horizon, no matter what bike type.

Regardless of the wheel size (650c, 700c, 24", 26", 27.5", 29"), the bike and rider are always perfectly level.

It accepts all kinds of bicycles: road, tri, mountain bikes (including Lefty, RS-1, Thru Axle), cross, track, etc. and a wide range of sizes. Since we are sought after by many juniors, the fit rig can accommodate as small as 24in wheels and race bicycles for kids as young as 7 years old. See here the junior program.

It's a thing of beauty - and quite possibly the only one of its kind in the world.


Our Fit Rig was born on a simple piece of paper, straight out of the mind of our founder, owner and Master bike fitter Steffi.

One of the motivations for its existence was the very basic necessity for fit to be successful: a level bike.

This was her thought processes:

"I see many fitters using the wheel block that came with their cycle-trainer - I've seen people even use books under the front wheel! I don't understand why. The wheel block is not designed for bike fitting: it's not level; it's not solidly affixed to the ground. Bike fitting protocols have the specific need for the bike to be perfectly level -and stable. When fitters use a wheel block, they are really setting you up for failure. Customers cannot benefit from the fit done in this fashion. That's not acceptable. I wasn't going to let this happen to our customers."


An additional motivator was the need for a stable platform.

"I realized that with Retül's 1mm measuring accuracy, I needed to create a supporting apparatus that would help me separate the noise of the bike's induced secondary motion from the organic movement of the rider. We have to take motion capture data at high power level to be meaningful. Everyone pedals pretty when they are comfy. We learn nothing from that.  But with the rider at high power output we put a lot of stress on the fit rig. So, I designed the apparatus to be very stable. This way, the collected data is accurate and actionable. We can't accept bad data. The success of the fit depends on it."

And so the bike fitting apparatus, AKA the Fit Rig, came to life from these very important observations.

It went through stages of development and growth. It took input from our talented fabricator and from our customers. It had to keep up with its developer's imagination and the growing complexity of our customer's needs.

"This is a product that's completely transparent to the customer. It's expected to do its job as intuitively as its functionality appears to them. But it deserves a lot of attention, because the fit rig is what allows me to do what I do best for you."

Much attention was devoted to making specialty parts to allow for a wide-range of bicycle sizes and types.

"We studied many bikes and components. We developed the fit rig with modular and replaceable parts, so it could transform to accept the many variations in bicycle design. Ad-hoc parts had to be developed to address the challenges of ever-changing fork and wheel attachment points. We work with a wide range of rider, from very young to very tall. The fit rig had to keep up with all of that. The latest challenge is with fatty and plus-sized mountain bikes."

The opportunity for the fit rig to be also an information and media center became apparent shortly after the first prototype was build. In version 2.0 the fit rig was outfitted with a 20in LCD monitor and a laptop PC station. A large boxed fan was introduced for rider's comfort. 

"I wanted my customers to see the data I see. This way, I can make you part of your bike fit; get you involved. I can explain each step of the bike fitting process, helping you understanding what I am doing and giving you the opportunity for active feedback. It also helps quantify the improvements from each change in your position. It's very neat."

In version 3.0, the fit rig had grown to two side-by-side 22in wide-screen LED monitors with two laptop PCs, a Computrainer command center and a tool tray for a full complement of bike fitting tools at our fingertip. The boxed fan location was further improved to accommodate the many cooling preferences of each client.

With tests, re-designs and improvements, the fit rig came to exist as it does today: the perfect complement to bike fitting and performance testing.

Come test it for yourself!


A sizing or fit bicycle is a must-have piece of equipment for any bike fitting operation that wants to be a legitimate bike fitting business. It's the foundation for sizing customers looking to buy a new or used bicycle. It's the cornerstone of pre-sale consultation services.

 If a bike fitter doesn't have a sizing/fit bicycle (or knows how to use it), then it's not a reputable business.

"Even though we don't sell bicycles, much of our activities revolve around  advising customers on the right size and geometry. Exactly because we don't sell bicycles, our bike sizing services are sought after for a completely unbiased advise."

When we were faced with the decision of purchasing a sizing/fit bicycle, we searched all commercially available products.

The need for developing our own custom sizing rig arose from the realization that there is a gap in these commercially available sizing/fit bicycles and the advanced features we felt are needed to properly size modern bicycles.

Our founder, owner and senior fitter Steffi decided to develop a sizing technology to overcome the common limitation of all currently available sizing/fit bicycles: the simulation of the head tube angle and seat tube angle.

"All commercially available sizing/fit bicycles are adjustable only in 2D: horizontally and vertically. They forgo the ability to emulate angles like the head tube angle and the seat tube angle because it's more difficult to engineer and more expensive to fabricate. Some of these sizing/fit bicycles look very sophisticated. Some are controlled by servo motors connected to a computer. They look very fancy. But that doesn't overcome the underlying limitation. Some attempt to use software to calculate post-fit the angles. It doesn't work. It's just inaccurate".

Our fitter knows well. We developed our own proprietary software, Dream Bike to attempt overcoming this issue with more sophisticated algorithms. We introduced a very advanced stem emulation which accounted for many stem production variations. Our sizing rig in version 2.x was 2D and relied on our software to predict head angles. It was good, but not great. We saw the software predictions get to within 2-3mm of real life. That margin of error is the difference in one size in a bike (hint: look how the reach and stack vary by size). This observation was our motivator in developing our own sizing/fit bike technology. We discuss this further in our bike sizing article and in our custom geometry page.

The ability to simulate the head tube angle is vital in determining the right stem length and rise as well as the correct handlebar reach. The sizing rig can emulate any head angle and even the headset and spacers set up for a hi-fidelity bike analog.

During the sizing session, the length of the stem is used as a check point: if the stem is too short, it means the geometry being tested is too big; too long and the bike is too small.

For pre-sales consultation, the head angle emulation allows us to complete the sizing process with a spec sheet that includes the correct length and rise of the stem, so the bike can be spec'ed this way. For customers looking for advanced aero bikes, this is a major cost saving feature, as it allows to spec out the size of the integrated aero bar+stem combination. These sophisticated aero bars are expensive to replace and highly proprietary to each brand. Knowing the right size can make a big difference in cost and waiting time.

The ability to simulate seat tube angle is crucial in the assessment of the crank length. These two parameters are locked in a performance dance that must be closely managed to avoid the potential for injuries and to maximize performance.

Because we are sought by customers who travel world-wide to get fitted and can't bring their own bike, the ability to offer a high-fidelity bike emulation is vital in their success to take their fit back home and transfer it successful to their bike while thousands of mules away from us.

It's a real game changer.

"What this size rig does is simply amazing. Coupled with the Retül motion capture technology, it's such an advanced tool, we can use it to simulate any bike, any size. It's so powerful, we can design a custom bicycle literally underneath you, sized for the way you interact with it."

The Size Rig can transform itself and simulate any bike model geometry and size: Road, Tri, Mountain. We can input all the relevant bike geometry specifications of the model(s) you want to test out: Seat Tube length, Top Tube Length, Head Tube Reach and Stack,

Quite possibly the most advanced sizing/fit bicycle because of our unique, proprietary engineering of the front-end: the only of its kind with variable head angles.

It is so sophisticated in its flexibility that it can be used to custom design a bike to your body specifications.

Cranking some serious wattage on the finished Fit Rig

The Fit Rig is not only a riding conditions simulator, but also an information center

The original sketch that started it all.

The early prototyping and manufacturing stages of the front wheel support system

Version 1.0 of the fit rig while being build.

Prototype V2.0 improved on the original design with media center support








Version 3.x of the Size Rig is a powerful tool adjustable in 3D.

Version 2.x lacked the ability to adjust in 3D. The limitations of the front-end could not be supplemented by computer simulations. It had to be improved.

Our proprietary Dream Bike software was developed to overcome limitations in bike sizing. It grew to such a powerful tool, that is the only of its kind. It takes Retül bike fitting data and bike geometry data to design a custom bike


Visit Us on   and Like Us   

© Copyright 2015 All rights reserved.    | For cyclists. By cyclists | Specialized in Bike Fitting only |