I can’t see patent issues. All the program needs to do is apply some sort of gear-related multiplier to the resistance setting, before sending it to the trainer. Then obviously they need to implement a form of virtual shifting, which then changes the multiplier value.
For example, if you ride up a 5% hill in zwift, zwifts tells the trainer to set a resistance that simulates that. But if you shift to a lighter gear, the resistance is something 0.x times the 5% resistance.
(In reality, outdoor resistance also dependa on speed, so shifting to a lighter gear and slowing down will both have an impact on the power you need to produce. But considering how bad zwift physics are in other aspects, I wouldn’t bet on them implementing that.)
Well, there are patents on both the cog attachment(!) and the virtual shifting implementation itself:
I don’t have the time, inclination, or patent expertise to dig in to how much that might limit others from coming up with their own, more open, solutions, though.
Someone gave me a free Zwifthub recently. I started to use TR for interval training so I never shift, ever. The cassette on the hub doesn’t match my bike, but it doesn’t really matter since I don’t shift. The only issue is, the cassette is quite noisy when pedaling. I’m wondering if getting the upgrade kit for my Hub would be a good idea here. Or is it not since I don’t ever shift?
In terms of noise, you will most likely appreciate the upgrade (based off initial reviews). In terms of trainer performance, you likely won’t notice any difference.
Been digesting this release and several tangential thoughts came to mind:
I am amazed I haven’t seen wide cries for getting shifting info displayed in Zwift for the existing smart bikes. Likely I just missed the places these show up, but I expect getting this info displayed in Zwift for Wahoo, Tacx, Stages and Wattbike would be welcomed by those users. One case of the new Wahoo Kickr Shift Bike in particular since it ditched the on-bike indicators on the regular Kickr Bike. I know some of the other bikes have on board or app based indicators, but see the on-screen option as likely a preferred choice if/when Zwift decides to open that up.
With the new Cog option, I am curious to see the actual width of that cog installed. I wonder if that width is a possible restriction for some 12 speed or even 13 speed chain options? Specifically the cog width against the chain inner width between the narrow plates. They probably have clearance, but it could be an issue in addition to the roller diameter problem with stuff like the SRAM Flat Top chains.
I was initially confused about why Zwift chose to setup the Click operation as they did:
The fact that it pairs with the Zwift app, which then relays to the trainer seemed like an extra step = Click device > Zwift app > Hub trainer
I thought a more direct Click to Hub would be more straight forward, but now think there are good reasons for the actual setup they chose.
First and foremost, connection with the Zwift app in the middle allows the Play controller to be used for shifting which is a great function from what I have seen. That alone may be the only reason since it opens that door within the Zwift ecosystem at least.
But the Zwift in the middle also at least makes it possible for the Click and/or Play to eventually be paired to non-Zwift trainers. They don’t do this now, but it is an apparent possibility from what I’ve seen. Adding that to other trainers could lead to more device sales (Cog+Click or Play) for Zwift to expand revenue on that side.
Not interested in the shifting element of this, just the hardware side. If I can run ERG mode forever with my different bikes I’ll be perfectly content.
There is not much magic in the Cog. As I mentioned above and in a thread from long ago, people can just make a single-speed conversion on their smart trainer in the same way that is done on a regular bike wheel.
Just some spacers and cog of choice, setup for desired chain line and some form of tensioner (rear derailleur or spring tensioner mounted in the hanger) and a person is set for at least ERG use with a range of bikes and drivetrains. There are many kits and DIY hacks out there that people can do right now.
I even considered suggesting that people could reinstall their current cassette with a different order on their loose cogs & spacers. Decide what cog size they want, and where it sits best for chain line, then stack at least 2 spacers next to that cog for clearance, and resume with the leftover cogs. It would be totally incompatible with shifting if someone tried, but it would leverage existing parts. Would be “free” since they are just arranging the existing components. This depends a bit on how many cogs are combined on a spider at the large end. But I think most should have enough spacers and loose cogs to juggle and make a double-wide opening next to a desired cog. (pic & info in my next comment below)
The main “new” thing on the Cog is the shroud that should make installing a bike and aligning the chain to the cog a bit easier. But it’s likely a bonus feature that is not necessary. Add to that the fact that it would take minimal work to design and 3D print similar shrouds for anyone that really wants them.
As I suggested above, just take a middle cog from an existing cassette, put spacers around it to make it sit in the middle of the freehub, and you’re good to go.
At least my 11-speed sram cassettes have separate sprockets (bar the biggest ones), so you could just take the 15t or whatever and use it on its own. Spacers (essentially short sections of tube can be found in single-speed converter kits, or just made from pipes. Might need a bit of fiddling to get the tension right.
(I’d actually use a middle sprocket and the 11t - the 11t to keep it all together, and then screw the lock ring in.)
Here is one example of swapping order for Shimano Ultegra 11-speed. Not every cassette brand or model matches this construction, so there may be more or less ability with different options.
IIRC, there is a built-in spacer on part (9), so pulling one spacer (11) on the inside of (8) should give double gap inboard.
Then pull one more over on the other side of (7) and you have (8) mostly centered with a double gap on both sides.
That is just one example, as this may work similarly with any of the true single width cogs if you don’t want whatever the tooth count is on the normal setup for (8).
I need to check on stuff like the typical Sunrace 11-28 or 11-25 speed that seem common on Kickr’s at least.
For those that have been around long enough, when freehubs were first introduced for Shimano, you could build up whatever cassette you wanted, cog by cog.
There was even a display board form Shimano that had every cog on it sequentially…you could just pick and choose what you wanted. Straight block 8 spd for crits? No problem…make a 12-19 (so sweet!!) “Climbing” cassette for the mountains? Start with a 13 and work up to a 27t (which I think was the max for road at the time).
However, durability became an issue as the individual cogs were digging into the freehub splines, making removal / replacement challenging (if not impossible at times).
Yup, cog bites in FH bodies are a real deal for those hitting some decent power. The extra wide base (from Wolf Tooth and BMX cog makers) or kits like below help spread the load.
Back when I had a Kickr I mostly used my 8 speed bike on it with an 8 speed cassette. From time to time, I’d throw the 11 speed bike on and find a “magic gear” that wouldn’t skip or make much noise.
Not that we’ve see, but it seems a replaceable design generally speaking. Just not sure if it’s a standard cog mount base or more specific to their design.
@GPLama@dcrainmaker Any idea if this would work with an Ekar 13 speed chain? I see it spec’d as 9-12 speed, but it would be nice to finally be able to put an Ekar bike on a trainer.
