Zwift stats v road stats


(C Ome On You Bhoys In Green) #1

Hi, I am new to zwift and I am a pretty poor on the bike to be honest. When out on the road I cycle and have a blether with my pals and stop start all the time for a wee snack or a photo down the canal. Problem I have is I cycled 27 miles on the road taking a strava “moving time” of 1hr 55 as an example with an average speed of 14mph whereas I use zwift and I cycle in a “race” ha ha! But do 14 miles in 45 odd minutes. I have a mechanical trainer listed in zwift and a speed cadence sensor(I run it on setting 3 - magnet is 1-6) however I cannot get my head around the difference in average speed and distance from the road to zwift. In zwift I can coast putting out 180 watts but in the first 3 miles or do I can manage 220-250 watts .Obviously there is no wind, hills , dogs, rain, dogsh*t and in zwift I really spin those legs until I cramp in my calf’s.

My strava data after a zwift race makes me look like I can cycle.

Is this normal ? I am thinking if I took my bike out on the road with no headwind, hardest gear and leathered it for 45 miles would I make 14 miles in the time.

In other words I’m struggling as zwift data is great compared to my road data.

Hope this makes sense.
Ta
Martin


(Paul Allen) #2

Zwift has no wind, you don’t have to stop or slow down for corners, there are more cyclist so you get a better drafting benefit and other differences. Speed and distance are not a good way to compare, power over time is. You are also using a speed sensor to estimate watts which is then converted to speed within the game and there can be a margin of error. The terrain between your outdoor ride and the Zwift ride are more than likely completely different.

The only real way you can compare indoor (Zwift) rides with outdoor rides is if you are using the same power meter for both and compare the watts over time.

Just to let you know, my bike speed while doing a triathlon are very similar to what I do in Zwift. I also use a TT/Tri bike for both Zwift and IRL races.


(Steve Copeland) #3

My Zwift speeds and my road speeds are quite close. For a similar route to the Watopia hilly loop I would average around 29kmh outside and about 32 on Zwift. Accounting for the lack of braking and wind its pretty close and the important power readings from my Vector 3s against my TacX Neo are very consistent. But when I first started there was a massive gap. What I do know is that Zwift has made a massive difference to my cycling and running ability. I am level 20 running on Zwift and only 15 on cycle as I don’t tend to use the turbo in the good weather. I expect to see the cycle level rise a lot over the winter!!


(Seb ten Cate) #4

Using bike calculator (Google it) you can see that 180 watts will result in 18.6 mph on a flat road with no wind. A 10 mph head wind slows you down to 13 mph, but on the way back a 10 mph tail wind increases your speed to 25 mph. So with 180 watts on the road, you should be a bit faster than 14 mph, unless you’re very unlucky with the wind direction.


(C Ome On You Bhoys In Green) #5

Hi, thanks for the info.
If swift says 200 watts then I believe I can cycle away at 20mph with the wind at my back.

I’m not really I to cycling so I have a lot to learn.

The main thing is that I can join a swift group ride and after 45 mins I am knackered. So I am getting good exercise regardless. I will monitor the next few months and see where I am at.
Thanks
Martin


(Devin Knickerbocker2522) #6

I think you can compare even if you do use different power meters. Sure, it won’t be exactly correct, but most power meters are really similar in terms of accuracy, around the range of 1.5 to 2.0%. As long as each one is calibrated, that’s really just a rounding error at most.