Optimistic Zwift?

naavt

I’ve swapped my Kinetic Road Machine Smart for a Kickr Snap and ran Zwift for the first time yesterday.

The whole thing is a great idea but isn’t Zwift being overly optimistic?

I say this because from one moment to the next I’m able to cycle at greater speeds, obviously ending up doing much more kms for the same amount of time that I ever did on my Road Machine and Kinetic Fit App.

Since I have found that somewhat weird, I paired my Elemnt Bolt in passive mode to read my actual speed and my my... It was way of!!! (Zwift showing 10kms plus at times from what Bolt reads)

Am I doing something wrong or is there any catch that I’m not seeing? I’ve warmed up the Kickr and made a spindown calibration before riding.

In the next few days I think I’ll try to ride some recorded routes on my Elemnt, just to see if the effort difference is so way off as I see on Zwift, but if anyone can shed a light on the subject I’ll be very appreciated.

jgsi

No, you are right in your assumption - Zwift really plays to the audience it needs for its income stream.
Real world pootling speeds do not flatter.

dannbodge

Zwift calculates speed using the power, rider weight and gradient.

No idea how your bolt will be calculating speed, but it's probably reading flywheel speed and doing some calcs based on that.

napoleond

Riding Zwift or the turbo in general is all about the amount time in training zone for me. The miles are irrelevant. Totally irrelevant.

naavt

Dannbodge wrote:

Zwift calculates speed using the power, rider weight and gradient.

No idea how your bolt will be calculating speed, but it's probably reading flywheel speed and doing some calcs based on that.

Nope. Have a connected Wahoo speed sensor in the back wheel, so the speed in my Bolt is 100% accurate.

NapoleonD wrote:

Riding Zwift or the turbo in general is all about the amount time in training zone for me. The miles are irrelevant. Totally irrelevant.

Not for me. If Zwift is selling me an "immersive" experience, I want to experience real word efforts. The more so with an updated price tag for 2018.

I don't want to ride a century in Zwift feeling that I could do it again just after that, just to discover that those numbers were completely divorced from reality after riding a century in the real world.

fat daddy

naavt wrote:

Nope. Have a connected Wahoo speed sensor in the back wheel, so the speed in my Bolt is 100% accurate.

its 100% accurate at counting wheel revolutions ... that is all real world speed is, distance / time. The thing is though you havent actually gone anywhere all your bolt is doing whilst you are stationary in your garage is telling you how quickly your rear wheel is going around.

Zwift uses applied power and applies that to its algorithm to work out virtual world speed based on your weight, aerodynamics, current road incline, drafting the bike you are using the wheels you are using.

fenix

It's slightly faster than the real world - but you don't slow for corners or junctions or lights etc.... And no wind resistance.

I also find it slower up hill than I'd expect.

I'd really not worry too much though - it's not about the miles as Nap D says - it's the time you spend on the bike.

N0bodyOfTheGoat

Over the last week, I've chuckled to myself at how kamikaze my Zwift virtual rider descends and takes corners.

But what it did make me do is focus on power readings from my turbo, trying to stay at ~160-220W on the flat and downhill, while trying to stay at ~240-280W on the climbs and killing myself trying to peak at 450W+ for the final 0.2 miles of races.

I wonder how long it might be before random wind direction and strength are introduced.

napoleond

naavt wrote:

Dannbodge wrote:

Zwift calculates speed using the power, rider weight and gradient.

No idea how your bolt will be calculating speed, but it's probably reading flywheel speed and doing some calcs based on that.

Nope. Have a connected Wahoo speed sensor in the back wheel, so the speed in my Bolt is 100% accurate.

NapoleonD wrote:

Riding Zwift or the turbo in general is all about the amount time in training zone for me. The miles are irrelevant. Totally irrelevant.

Not for me. If Zwift is selling me an "immersive" experience, I want to experience real word efforts. The more so with an updated price tag for 2018.

I don't want to ride a century in Zwift feeling that I could do it again just after that, just to discover that those numbers were completely divorced from reality after riding a century in the real world.

Then ride at the power you would normally do for a century for the time it would normally take you to do a century?

napoleond

If you’re that worried, use Rouvy as that is very close to real world times. Especially on courses I’ve created myself to recce race routes.

fenix

naavt wrote:

I don't want to ride a century in Zwift feeling that I could do it again just after that, just to discover that those numbers were completely divorced from reality after riding a century in the real world.

It's really not that far out for me - fractions of a mph I reckon. What routes are you doing ? Have you done a hilly one ?

naavt

Fenix wrote:

It's really not that far out for me - fractions of a mph I reckon. What routes are you doing ? Have you done a hilly one ?

On the logged ride it shows 36Kms with a 445 elevation gain.

fenix

My last ride was around 15.6mph around the Surrey Hills on Zwift. Total elevation just over 2000 Feet.
There's no way that my speed was exaggerated by 6mph...

I do have a powermeter though - so I think the issue here might be that the OP's turbo isnt calibratred correctly and is registering higher.

CRAIGO5000

It's extremely realistic in my book.

I've raced on Zwift and in an hour doing just under 30 miles. The variables were no stopping and riding in a huge pack for maximum aero gains.

Comparing that to a 30 mile road race and the times were very similar - power was also consistent. I also didn't stop in the race or slow down much and was covered by 30 other racers. In both cases, average speed was upper regions of 25mph+

radhartgeorge

I have found my real world speeds are slower but that is largely a product of having lower average watts outside than I can achieve inside - traffic, corners, icy descents preventing me from going hard. You'd be amazed what a 1 minute descent with 0 watts does to your average.

MiddleRinger

naavt wrote:

Nope. Have a connected Wahoo speed sensor in the back wheel, so the speed in my Bolt is 100% accurate.

Accurate to your turbo wheel speed. Your cycle computer is calculating speeds from your rear wheel - it does not account for the slowing down or speeding up of your virtual ride depending on the in-game gradients. You don't even need to use your BOLT while riding on Zwift. Just concentrate on the in-game metrics and don't worry about your cycle computer.

naavt

Thank you all for sharing your thoughts. The in-game variables that most of you talk about makes sense.