Wheel Diameter

(' BTCNJ-Jim-HUBS(D)) #1

Any plans for incorporating input for different wheel diameters ?

(Michael Henasey) #2


everyone is riding the same virtual wheel size in game.

if you are using a power meter, the speed of your wheel (and its wheel diameter with tire) makes no difference in game.

if you are not using power and instead using z-power, wheel speed would be affected if you were riding a mtb with 26" wheels or maybe 29" wheels. I guess if that’s all you have to ride then your numbers will be skewed. but wouldn’t you feel out of place riding a 29" mtb on a trainer while your avatar in game is on a road bike? maybe Zwift 2.0 will offer mtb courses and bikes but until then, this here is for roadies only :wink:


(Brian McPherson) #3

Maybe people on zPower want more accurate numbers instead of ones that are obviously inflated because smaller wheel/tire sizes aren’t supported? Not even every 700x23c tire has the exact same circumference when inflated properly. It could be measured and then given the proper size like how trainerroad supports exact mm circumference measurements.

(Michael Henasey) #4

But if you want accurate, Brian, you must use a power meter…

(Brian McPherson) #5

I don’t think it’s a good idea to force people into having less accurate numbers than they could be getting, a lot of the nice classic trainers have fairly predictable power profiles. Say someone’s youngster has a road bike with 26" wheels, why should they be forced to drop that kind of money on a power meter if they want to use zwift? I have a powertap hub on my road bike, RPE of using the powertap versus having zwift calculate zPower is very close for the same amount of watts with the ‘proper’ sized tires, but it’s completely inflated if I stick my mountain bike on it which doesn’t have a powertap hub.

(Michael Henasey) #6

I get ya, Brian, if a 26" mtb is all you got, then that’s all you got.

i’m sure they will add wheel circumference in the future.

until then, its just for 700c roadies.

and if you want accurate, then…

(Eric C. (Zwift HQ)) #7

Definitely planned.

(A rider) #8

Ummm… just include a required spindown calculation with a required tire size input.

(Linda Williams) #9

my data is inaccurate and i would LOVE to see an option to change wheel sizes.  I’m on 650cc wheels and using Zpower.  Although i enjoy being much faster than normal, i am being penalized for being on a smaller bike.

my vote is for wheel size options.

(James Windley) #10

yeah, should be simple,… old vetta bike computers could have wheel circ added to determine speed in the 80’s, why not have this option on an actual ‘virtual reality’ computer program.  Nothing wrong with Zpower wanting to be more accurate.   

(Peter Fearn) #11

Definitely a vote for the capacity to adjust wheel size. Despite seeing her dad in ruins during a training session my kids loves the game play and has asked for their own account. As they ride 26" wheels, as do a significant minority of smaller adult females, then its only right that they receive accurate data.

Related, wouldn’t it be an idea to have multiple bike setups. That way it would also be possible to switch between MTB and Road bike within the same account. Perhaps against some of the purists here, but until MTB circuits come along it would at least offer realistic stats for anyone grinding away with MTB on turbo. I’m also sure some of the roadies would enjoy flying past too:-)

(Miranda Hughes) #12

Another smaller female rider on a 650c setup without a power meter, adding my hearty vote for wheel circumference input. It is no fun thrashing the field when you don’t earn it. 


(Miranda Hughes) #13



(Suneil Dham) #14

Another vote for wheel size input. I have a road bike with regular 700c wheels on a TACX smart trainer with power. However I also have an Elliptigo on a Kinetic Fluid trainer that has 20" wheels. Works fine with virtual power on Trainerroad. … would love to be able to use it in Zwift too!

(Steve Epstein) #15

Another vote. I’m not a hard core rider - I have an old touring bike with 27 inch wheels, but want to use it to get in better shape. Zwift is a great way to do that and I’m checking it out. TrainerRoad offers the ability to alter your wheel diameter for more accurate numbers with virtual power, so I’m expecting Zwift could do the same.

Until then, with larger wheels I’m being penalized in speed and ZPower:(

(semi shild) #16

Hi. I am using reebok z9 bike but i want my wahoo speed/cadence datas to be sync for exampel with Zwift but all about these default traienrs settings. it is correct to say that swift dont give any other options for example to change wheel size which for my bike is 6 meteres to get correct calibrated speed. So yeah, you should give an option to change wheel size to get more customers.

(Binette Vincent) #17

Hey Zwift!
Any timeline regarding wheel diameter support?  

(Joshua Tootell) #18

Any updates on this? I’m considering a subscription for some indoor training, but NOT if I can’t get decent numbers. I’m on a older 650c TT bike and it really inflates my numbers. I primarily race mountain bikes so I have no interest in buying another bike and don’t have the budget for a power meter.

(B V) #19

Same here, 650 wheels, 6 days to go in the subscription period, definitely a deal breaker for me.
It was planned 12 months ago, apparently: where are we on this?

(A rider) #20

Well… they have the time for adding the ability to ride through a volcano… what more do you want?

Oh yeah, 3D, that will be awesome LOL. I can’t wait to wear a VR headset when doing max power sprints.