# What is the resistance on a watt bike like?

Discussion in 'Beginners' started by AnotherCyclingFan, 25 Feb 2018.

1. ### AnotherCyclingFanNew Member

does anyone know what the resistance on a wattbike is like? Or does anyone know how the resistance is calculated based on your weight?

2. ### SpecialeyesÜber Member

Location:
Essex
Wattbike resistance bears no relation to your weight. You can 'set and forget' and concentrate on your watts output, or you can mix it up as you ride by varying both the air resistance and magnetic resistance to simulate climbs etc. according to what you want to achieve. Check this video:

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3. OP

### AnotherCyclingFanNew Member

Thanks for the reply! It’s only because I heard there was a function that basically suggests the resistance for you based on the amount that you weigh?

4. ### simon walshÜber Member

FYI there are two models trainer which has a lighter resistance and also the pro which is a lot harder. From memory a level 10 on the trainer is equivalent to 5 on the pro model

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5. ### MilkfloatVeteran

Location:
Warwick
There is also the Wattbike Atom that is a smart trainer and thus weight is crucial.

The Atom and The Trainer both have a maximum of 2000W the Pro has a maximum 3760W. Trust me you are unlikely to need the Pro.

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6. ### BolloChaaaaaa!

Location:
Winch
You're going to have to explain that one to me.

The resistance applied to an axle on a smart trainer (or any other trainer for that matter) has nothing to do with the rider's weight, it's just Power = torque x angular speed, where the resisting torque is provided by some form of mechanical or magnetic resistance. There's no rider in the equation - the trainer doesn't know whether it's me (80kg, coughing up lung) or Quintana (58kg, impassive) generating 400W. It's just gripping the axle with a set resistance.

All a smart trainer does (in erg mode) is reduce the resisting torque with increasing cadence and vice versa to maintain a hopefully constant power. This gives rise to the "Smart Trainer Death Grip" (tm Bollo) where as you get more knackered, your cadence drops so the Smart Trainer ramps up the resisting torque.

The ability of a rider to generate power is only indirectly related to weight, as a heavier rider may (or may not) have more muscle and be able to apply more force on the pedals (and hence torque) to maintain an equilibrium with a higher resistance. It only time it becomes directly proportional to rider weight when the rider just stands on a pedal and the force applied down is solely due to gravity. It won't get you very far though.

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7. ### MilkfloatVeteran

Location:
Warwick
I guess I was adding confusion - as you say the weight is not affecting the watts. I was trying to suggest that weight is very important in the software behind the smart trainer. Basically, i am trying to second guess what the OP actually means and wants to know.

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8. ### HLaBMarie Attoinette Fan

He was maybe being picky but a Mate of mine got a Watt bike Atom as a gift. He sent it back saying it was useless for interval training :-/