Hello all. Can you use a 7-speed bike on the Zwift Hub One. The official Zwift reply is that you’d have to use a 7 speed cassette on the conventional Zwift trainer. But I’ve also heard that the Zwift Hub One should theoretically take any bike that you can hitch up to a trainer. Mine is an old 7 speed road bike that I’ve used for ages on a Wahoo Kickr Core…with a few spacers. I can’t see any reason why it shouldn’t be compatible with the Zwift Hub One? Am I missing something?
What’s the spacing between your rear dropouts?
Hi Tom - it’s 135mm
I am not sure why you would go from a Kickr Core to a Zwift Hub the ride feel is very similar. Only reason to do the switch is if you planning on buying the Zwift Cog at the same time to make your 7 speed bike have more gears (virtual gearing). You might need to bend your frame a tiny bit to make it fit the Zwift Hub and align the chain with the cog so it’s straight.
I can’t think of a reason why it wouldn’t work, but in any case you can just buy it and if it doesn’t work to your expectations, remove the cog from the freehub and install your cassette on it. The cog is mounted on the same freehub that the “classic” trainer comes with, and you don’t need a cassette from Zwift, plus you’d get the Click shifter and be able to use virtual shifting even if you install your cassette.
Thanks…it’s a 135mm dropout space which I thought was quite standard. And yes…buying for virtual gearing. I don’t want to bend my frame 
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You won’t need to bend the frame. If the chainline sucks you could just remove the plastic bits from the Cog and replace them with spacers to put it where you want. Without the guardrails you would have the possibility of accidentally shifting the chain off the cog, but you could bodge something together to do that if you want (eg, put some large cassette cogs on either side of the 14t cog). Or just don’t touch the shifter.
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I thought that was the case - re: the free-hub. So thanks for confirming.
Superb…cheers for the advice. I have a lot of spacers
135mm should work just fine. Paul already said everything
In the future you might wanna look into Zwift Play as it gives you an easier option to change gears using the button on either side of the controllers located on either side of handlebars much like switching gears on your regular bike. I know that I am one who changes gears quite a lot and they makes it a lot more convient.
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I have Zwift Play…they are great devices. I want to use those side buttons!
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Would you need an 8 speed chain or could you use the 7 speed chain length?
The right chain length is a matter of the sizes of the cogs, independent of the number of cogs. Rough guess is that the chain length from a 7sp bike should be fine with the cog on the Hub One–iirc it’s a 14t cog, and any 7sp cassette will have a 14
There is a difference between 7sp and 8sp chain widths, however. An 8sp chain will have a narrower outer width than 7sp. The more cogs a drivetrain has in general, the narrower the chain needs to be.
So a 7sp chain should fit over the Hub One cog okay, but it might be the case that you’ll get some rubbing on the plastic doohicky things on either side, depending on your chain line. An 8sp chain would be a touch narrower in overall width, and you should be able to go to that if the 7sp chain is rubbing. (Internal widths are the same on 7 and 8 chains, so an 8sp chain should work with the front chainrings too.)
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Also depends on whether the chain on the bike is actually a 7 speed chain. Many aftermarket chains these days are sold as “6/7/8” - basically they are 8 speed chains. If you know which chain is on the bike you can look it up to find out if it’s marketed as 8-speed compatible.
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I’m sure that advice from Shuji I’ve seen recently would be - you have a well worn chain and now with a new Hub One Cog why not use a new chain.
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Hi new to this,
Thinking of getting zwift hub one and buy a cheap road bike will these work on it i am a complete novice so just need any advice.
Brand-X Road Bike - Selling on Chain Reaction
CROSS XTR 1400 27.5 inch Wheel Size Unisex Road Bike - Red - Selling on Argos
Any advice dont want to spend a fortune on bike as it will be in my attic. Or any other suggestions woild be greatly appreciated.
Thanks
Dave
Yes it should fit the trainer. The cog on the Hub One is designed for 8 speed chains (and narrower). Although this is a 7 speed bike, it may already have an 8 speed compatible chain on it, or if not you could install one. The symptom to look for would be the chain rubbing on the plastic guards on the cog.
Do you recommend a road bike that would be fine? Again doesnt have to be anything special it will stay in house in attic i am a total newbie to all this.
It’s hard to beat that bike on price. Of course it’s a very cheap low quality bike which means parts may wear out quicker, bearings will be rough, and it won’t get proper shop assembly because there’s no room in the price for that. Thankfully many of the parts are irrelevant since it’s a trainer bike (ie you don’t care about brakes or wheels). You can’t assume that the Click shifter that comes with the Zwift Hub will actually work, since there are a lot of problem reports about it. If it doesn’t you’ll have to care about shifting performance of the bike because you’d either have to put a cassette on the trainer or get a different trainer that would also require installing a cassette. So I’d say it’s not inconceivable that you might end up depending on mechanical shifting and that will be a weak point in a cheap bike that’s not set up by a bike mechanic.
The Triban RC120 (Decathlon) is a common choice for a somewhat better quality 8-speed bike that’s available in the UK (assuming that’s where you are).
Just found this as a recommendation on Google for Zwift would this work?
VRAi Fitness SB1000X Bluetooth Smart Exercise Bike | Kinomap, Smartphone Sport App Zwift Spin Bike | Live Video Streaming, Coaching & Training-Heavy Flywheel Gym Equipment for Home