Does anyone know the diameter of the latest Zwift Cog? The one with the orange disk. I’m about to get a smart trainer and give Zwift a go, but I have to make some adapter brackets for my Raleigh Rush hour with horizontal dropouts and 120mm spacing. I’ve found the Velobike kit, but saw the post about it interfering with the cog.
My best guess is 4” in diameter based on the packaging spec, but I would really appreciate someone measuring it for me—specifically the side with the orange disk, including the black housing. No worries, I can wait till I get the trainer, but I’m itching to start making the adapter.
Rough measurement yes looks like around 4", but if that’s too large you could lose the plastic bits and just use the cog itself with spacers arranged to put it in the right place, or use a third party single speed kit designed for an 11 speed Hyperglide freehub. There is no need to use the cog if it doesn’t work for you. Velobike sells that as well but cheaper ones are available everywhere.
The 4" part is the inside plastic ring closest to the trainer so that’s not going to hit anything near the dropouts. The outboard plastic bits are smaller.
Shuji at Zwift HQ here. You don’t mention what trainer you have, and that is a crucial consideration for using it with a track bike. I’d advise you to hold off on purchasing the Velobike adapter (which one, by the way? They make several) until we can talk through your expectations of how this might work for your track training.
The Zwift Cog does not have any electronics in it. The magic of virtual shifting is a dance between the Zwift Click controller and the firmware of a smart trainer that supports virtual shifting. Will you be using using one of the supported trainers listed under the Zwift Cog Compatible trainers section of this article?
Are you planning on siting the frame ahead of the hub, and using some horizontal adaptors between the dropouts and the trainer axle? I would have thought that would also require some vertical support for the frame or the load on the dropout connection might cause it to sag and/or twist.
I ended up getting the JeyBlack Victory and love it. Everything is working perfectly!
The spacing on my frame is 120mm on the inside and very close to 130mm on the outside of the dropouts. So when I added the brackets to the outside, I was able to mount to the trainer, no problem. I also angled the hangers by 10 degrees to simulate derailleur hangers. I ended up making them longer than the Velobike adapters so they wouldn’t interfere with the Zwift Cog. I saw a post somewhere where they had to remove the plastic from the cog because the hardware was rubbing. I posted some images below, and I’m happy to share dimensions if anyone else wants to try.
Big thanks for your reply and for your offer to help me out. Means a heap!
I ended up making brackets with two bolts in each dropout, and they are long enough so the mounting hardware doesn’t interfere with the Zwift cog. So far, it’s working very well. I’m 180 lbs, and it’s showing no sign of moving! And it survived my first FTP ramp test! 231. Not sure if that’s good or not. I’ve been running for 15 years (25 miles a week), but never really rode a bike (maybe three times last year on recreational paved paths with my wife).
Oh, and I can’t seem to post a link here. But if you look me up on Instagram (@mustcreatethings) my latest post is a slideshow of what went into making it.
Here are a few photos of how they turned out. Hit me up with any questions!
