This guide is to help you assess your bike set up in advance of attending the turbo training studio. Yes, it is a bit of a faff to check your bike, but you only need to do it once and by providing the correct information, you will save time and stress (both yours and ours) in your first session with us. Properly filled out Athlete Questionnaires will be rewarded with our genuine appreciation and maybe even a respectful nod.

On the face of things, bike gearing might not seem particularly straightforward when you hear people talking about running an ’11:28′ or going on about Tony Martin running something crazy like a ’58’ during a time trial in the Tour de France.

This does sound like gibberish and even though you know you should make the right noises like, “oh wow!” or, “I have soiled myself with awe!”, inside you might be praying the conversation reverts back to Love Island.

There are three key parts of the bike to talk about when explaining bike gearing: the rear cassette (gears on the back wheel), the front chainrings (gears connected to the pedals by the pedal crank) and the axle set up (how the wheels attach to the bike frame).

You might also hear people talk about sprockets, cogs, gears or rings. They essentially mean the same thing. A gear on the cassette is a sprocket or a cog on the cassette. Cycling has its own language, with many different dialects and everyone will try to convince you their way of talking is the purest version!

The rear cassette
The most essential piece of information you should provide on your questionnaire regarding your bike’s gearing is what speed the cassette of gears on the rear wheel is and the ratio of gearing.  The video below will explain how to work out both or you can follow our instructions below:

The speed of the rear cassette simply means how many gears/sprockets/cogs there are on it. Count them and you will have your answer. Most road bikes will be either 10 or 11-speed, so 10 or 11 sprockets or gears on the rear wheel.

When it comes to the cassette gear ratios, count how many teeth the biggest and the smallest sprockets/gears have and that will be the answer. Don’t worry about the ones in between.

For example, the standard cassette that comes with the Wahoo KICKR is an 11-speed, 11:28. This means the cassette is has 11 gears at the back and the smallest cog has 11 teeth and the largest has 28 teeth.

Don’t worry if this does not match the cassette on your bike. Simply put what you have in your Athlete Questionnaire and we can make sure the cassette on the KICKR is appropriate for you.

Chainring ratios explained
For the purposes of the RIAK Fitness studio, the specifications of the front chainring are not overly important. However, it is still useful to know.

Typically, most road bikes will have two chainrings at the front, one smaller than the other. A lot of mountain bikes and female specific bikes might have three. Track bikes will have one.

To know what the ratio is, all you have to do is count the number of teeth on each ring. So, the large one might have something like 52 teeth and the smaller one 36. This means the chainrings are a 52:36. Often though, people will just mention the size of the big ring. In the example above, Tony Martin ran a 58 tooth chainring on the front.

In short, the more teeth on the big chainring, the bigger the gear and the harder it is to pedal. So a 58 is ridiculously big, with entry level bikes like the Specialized Allez or the Trek Domane running something more like a 50 tooth big chainring.

Axle type
There are two types of axle set up (the part of the wheel that attaches the wheel to the bike frame). This GCN video explains the difference between a quick release skewer and thru-axle set up.

If you have a thru-axle set up, please make sure you note this on your Athlete Questionnaire before attending the studio.

Axle width
Most modern road bikes have a 130mm axle width and use a quick release skewer (see GCN video above). If this is the case with your bike, it makes things very straightforward with regards to us getting your trainer set up before class. The photo below is an example of what we are talking about. This is a 130mm quick release axle configuration.

If you are unsure of the axle width, simply measure the distance between the inner surfaces of the rear drop outs and if it’s 130mm, then perfect! If not, jot it down in the Athlete Questionnaire you need to submit before attending and we will take care of the rest.


It is a bit more complicated when it comes to some new adventure, race and disk brake bikes, which have different set ups to the above. Disk brake bikes might have a slightly wider gap between the dropouts and so it is worth measuring this gap and including it in your Athlete Questionnaire before you pop down.

Likewise, if you have a thru axle configuration, often this gap between the dropouts can be a bit wider. Include the width of the thru-axle in your Athlete Questionnaire and we will make sure your trainer is set up properly for you.