Zwift Hub + mountain bike (40x11 max gear ratio) low resistance

Hi,

I’ve been trying to run my mountain bike on the zwift hub classic, but I’m always spinning out (100+ cadance at the highest gear, but only 100W).

This is not exclusive to zwift, I tried out mywhoosh this week, and have a similar issue if ERG is enabled. When ERG is disabled, I’m able to use 3 gears, and still spin out when putting in a lot of power.

Is this a malfunction? It can’t be that it is supposed to be like this, right?

Hello @Wouter_Heerwegh welcome to Zwift forums.

Some disappointing news first, then some really exciting news for you.

Up until 2023 - smart trainers were designed for road bikes and their taller gearing. Just as you would spin out your mountain bike’s biggest gear on flat roads outside - you could also spin out your trainer because your gearing wasn’t big enough. This applied to all direct-drive trainers, by the way.

The good news is that the Zwift Hub you own is capable of virtual gearing, and can overcome the physical gear limitation on your bike. More information about Virtual Gearing when we introduced it to existing Hub Classic owners such as you. This FAQ might also be useful.

During the first few seconds after your avatar spawns, Virtual Gearing will calculate what physical gearing is on your bike, and set your trainer in the 12th of 24 virtual gears. After that - you leave your derailleur alone and shift virtually using the Zwift Play controllers, or the Zwift Click. Both are available on the Zwift Shop, but for mountain bikes - you’ll want the Click and ZwiftCog combo. The Play is designed for drop handlebars and will not work with mountain bikes.

Hi @shooj,

It sounds logical that you would want to calculate the resustance as realistic as possible based on my gearing. I dont have a race bike myself, by I guess I could also swap out my crankset for a bigger one. What is the recommended crankset size?

Virtual gearing sounds nice, however, it’s annoying that I would have to buy controllers to make use of them. Wouldn’t it be possible to just manually put it in the biggest gear (through settings) so that I could use my actual gears? Especially since I could buy a new crankset for a similar price, and that would, according to you, solve my issues across all apps I would possibly use.

If you’re not interested in the Zwift virtual gearing products, you also have the option to use the QZ app to increase trainer resistance. It is a paid app but not very costly and comes with support from the developer, @Roberto_Viola . (qzfitness.com)

The Cog + Click upgrade package is less expensive than most cranksets, and you don’t have to use the Cog. You could use the Click controller in combination with the cassette you already have. You can’t buy the Click controller by itself, but you could consider the Cog as a spare freehub body that you might need in the future.

1 Like

Qz developer here! Let me know if you have any questions!