Realistic speed?

I feel like I ride much faster on Zwift Island than in real life… Am I wrong? 

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I find that i ride faster as well but as far as i know there is no wind on zwift and I am riding on bullet proof tires outside so i do get a bit more rolling resistance

. For me it is more on the downhill that i seem to go faster sooner. On the climbs i feel pretty much the same as outside. I did an outside ride of 54.6k and the next day 54k on Zwift and my times were 1hr 56 minutes outside and 1hr 47 minutes inside. I climbed about 520meters on Zwift and 586meters outside. The effort i did outside was higher but there was also a head wind half the time.

Overall i feel that it is quite close and I am more motivated to ride indoors then ever.

It’s pretty accurate for me.


Is your weight set correctly?  Does your measured wattage on the road match your wattage in zwift? 

I  think the CdA (used to calculate wind resistance) is generous for me. On the flats I seem to go faster in Zwift than in real life. I’m fairly tall, so that may be a factor: 6’2" 159 lbs  (187cm, 72kg).

I don’t think it’s making more than about a 2-3 km/h difference at 35 km/h, though. If you’re seeing more of a difference than that I would agree about checking your weight and wattage. What kind of bicycle trainer are you using?

Christian, I think I read somewhere that everyone has the same CdA on Zwift island, regardless of size.

Rob, I think Jon Mayfield confirmed that some time ago, but I think they may have updated the CdA in one of the most recent updates. I suspect CdA is now weight based. A few rides ago I drafted a heavier rider who was putting out 300 watts on the flat section while I was only doing about 210 watts. Of course it’s also possible that they just increased the drafting effect.

They have definitely changed the CdA lately. I am 6ft3 and 95kg and the other day I was following a rider doing a steady 310W and I was 22seconds behind. I was doing a steady workout myself on TR so as I started the downhill past the banjo player I upped the watts to 333 and by the time I reached the finish banner I was about 27 seconds behind. I think they have maybe went too far as I think with me being around 30kg heavier I should have caught up a fair bit. This means heavier guys will struggle to keep up now whereas before we could pick up some time downhill. Takes a bit of the fun for me I must admit.

It is a little faster.  I routinely do rides on Zwift that average around 35 kmh that would be closer to 33 kmh outside, but then my outdoor rides are often a little bit more hilly and inevitably have some wind.  Zwift is close enough for me and is pretty consistent from session to session so I don’t see much to be bothered over.  I just treat it like a fast course.

Thanks for your replies. Maybe Zwift gives more advantage to cyclists with a lower weight? Me, for example, I weigh 70kg. Maybe the W/kg thing is more in my advantage than it is for heavier guys?

I weight 61kg and have an FTP of 265. I’ll do a TR training session or generally blast around the island and will average a speed ~20mph which is on a par to what i’d achieve on a solo road ride.

Variables such as drafting will affect the outcome alot, much like if I went out with my club on a training ride. Anyone who hides at the back of a group will put out less effort.

I haven’t done a proper sprint in Watopia, but on the first island the speeds in the sprint were unrealistically high, mid to upper 40 mph range. Flattering, maybe, but not real. For me those same wattages would net me 37-40 mph. In real life I’m short on the bike so I get decent speed out of a given sprint wattage, so if anything I’d be faster than a comparable wattage sprinter who is taller (generic height comparison - I’d ride a size S bike, 50-52 cm).

It looks like the potential energy calculations when riding uphill are right but the added rolling resistance and or wind resistance due to being overweight look very odd. I have rides of 42 kmh while I never reach those speeds outside when there’s no wind at all. Maybe my power calculations are a bit off, I don’t have a powermeter outside.