In short, there really isn’t any difference between the 2 bikes. In fact they are the same thing. It is like mother and mom can refer to the same person but one is trademarked.
Indoor cycles/spin bikes are stationary indoor bikes except Spin Bikes is a registered trademark so is a . However, they are different to recumbent and upright bikes.
What are the features?
They have a heavy flywheel, adjustable seat and handlebars, robust and durable steel frames, a fixed gear mechanism, limited accessories, adjustable resistance levels and they are designed to be worked hard just like you do on an outdoor bike.
The accessories are limited so that it doesn’t take you away from the main focus of being on the bike which is to train. Also you don’t have somewhere on an outdoor bike to put your book or tablet to read and look at while you cycle around the streets or on a trail.
The heavy flywheel provides the natural riding motion and makes it feel more like you are riding your bike outside. The adjustable resistance levels are there to give you the toughness of riding up a hill.
The pedals have the same fitting as outdoor bike pedals and you can stand up on them in the same way you would when you are pushing hard to get up a hill or all out sprinting when outdoors. If you want you can change out the pedals to ones that you want that are fitted out for your specialist shoes.
The seat is a standard bike seat too. Just as you would expect they are uncomfortable. You can put gel covers on them or try padded bike shorts to help with the pain.
I don’t think there are many people who find bike seats comfortable. As with the pedals you can swap them out for a standard fitting bike seat you find more to your liking.
One main difference to outdoor bikes is the amount of adjustability you can do with indoor cycles/spin bikes. With most of these bikes you can move the seat vertically (like outdoor bikes) but you can also move it horizontally. The handlebars can also be moved vertically and in some cases horizontally. This is so that the bike can be made to fit people of different heights so they get an efficient workout.
The workout routines you do on the bikes can be the same but even here the terms can mean the same thing, but there are legal reasons why Spinning (R) and indoor cycling are not the same – the term Spinning (R) is legally protected and does refer to specific type of cycle training. So, if the gym or workout video you are following has not paid a fee to use the name they legally have to refer to it as something else such as indoor cycling but it could be the same type of routine, but it can also refer to a routine that adds other different elements too.
Spinning (R) vs Other Routines
The term spinning relates to a type of training created and developed by the people who make the Spinner brand spin bikes (See Spinner Sport Indoor Cycle). It was developed to give you a workout like you could get from using an outdoor bike – so there is sprinting, hill climbs and standing on the pedals etc but with your hands staying firmly on the handlebars. They also use heart rate training to ensure you get the best and most efficient workout you can.
So if you don’t do it on the outdoor bike training you don’t do it when you are Spinning (R). They have race day rides, endurance rides, hill climb rides ,recovery rides etc.
With other different named routines they can be similar but they aren’t necessarily limited to what you do on your outdoor bike. They introduce other exercises such as using hand weights to get some resistance work for the arms too. They are normally high intensity routines done to music and can often be seen as more fun than the Spinning (R) but you do need to be careful about falling off the bike when you are not using your hands to steady yourself.
So, unless it is from the brand Spinning(R) you are doing indoor cycling training on your spin bike/indoor cycle, even though you might be doing the same thing.
There is no difference in the equipment it is people use different names for the same thing – just as the English use the term crisps for potato chips. Most manufacturers name their bikes as indoor cycles but the common name used by most people is spin bike.
So, if you are looking for a bike for your own home to do your workouts at home you just need to levels and goals rather than worry about the different name and if they are for different purposes.