Now that Zwift has rolled out FutureWorks, I find myself thinking of new cycling features they could release for us to test. And I keep coming back to the draft.
Drafting Today
We know drafting on Zwift comes with its own set of challenges. If you doubt that Zwift drafting is a unique skillset, just watch an experienced outdoor racer hop onto Zwift for the first time and try in vain to hang with a hard-charging pack. They’ll fly off the front, then ease up and get spit out the back.
Why does this happen? Because drafting on Zwift is very different than drafting outdoors, for several reasons:
- No braking: without brakes, you can only change your pack position by increasing or decreasing your power. While this is what experienced racers do outdoors, a little bit of braking still comes in handy.
- No steering: when the game moves your avatar right and left, you don’t get to choose where and when you “slot in” to the pack.
- Riding through others: it’s too easy to ride through others in the Zwift pack, while in the real world if you tried the same tricks you would need to move around riders to avoid crashing.
- No draft “feel”: when you move out of the draft outdoors, you feel the air hit you immediately. On Zwift, you feel no change, as resistance does not change based on your drafting status.
From the items listed above, braking and steering are certainly coming down the road–the new crop of smart bikes already has buttons and levers to make it happen once Zwift to adds it to the game.
Riding through others is an issue Zwift can change in their positioning algorithm.
But I want to focus on the draft “feel.” Let’s dig into this a bit.
Feeling the Draft
Most cyclists understand the basics of drafting, since its an integral part of group riding and racing. Being “in the draft” means you experience reduced air resistance, because riders ahead of you are blocking some of the wind.
Typically, cyclists will tell you that drafting another rider reduces air resistance by 30%. But a recent supercomputer-powered study said that drafting in a large pro peloton can reduce air resistance by as much as 95%. Amazing!
What if your smart trainer’s resistance automatically dropped a bit when you entered the draft in Zwift… and increased when you left the draft? What if drafting behind twenty riders felt different than drafting behind just one?
Would that make the experience more intuitive and realistic? I think it would.
(It’s worth noting that other indoor cycling platforms support some sort of “draft feel”–Tacx Desktop Software and Veloton are two which come to mind.)
[adinserter block=”1″]
Slowing the Pack
One potential benefit of “feeling the draft” may be a reduction in overall group speeds, especially in double draft races. Currently, the “churn” at the front of the pack leads to artificially high speeds–I would guess 2-3mph too fast.
Perhaps if riders could “feel” their position in the pack things would calm down a bit, group speeds would drop, and breakaways could stand a better chance of sticking.
Those Devilish Details
Of course, implementing this in Zwift is not as easy as Jon Mayfield snapping his fingers. Ideally, Zwift would be able to send a simple “drafting factor” to our smart trainers, just as they send wind resistance, slope, track resistance, weight, and other parameters. (Smart trainers combine these parameters to set overall resistance multiple times each second.)
Here’s the thing: smart trainers use two different wireless protocols: ANT+ FE-C (ANT) and Bluetooth Smart FTMS (Bluetooth). The ANT specification does include a drafting factor. But the Bluetooth specification does not.
So Zwift would have to hack the Bluetooth side of things for now, perhaps just dropping overall wind resistance to mimic drafting. Perhaps Zwift could push for an update to the Bluetooth FTMS service, which hasn’t been revised since February 2017.
But for now, I would just be happy to see Zwift roll it out under FutureWorks for ANT+ FE-C users, so we could give it a go. It’s just one parameter, which hopefully means it would be easy to add much like Zwift added the weight parameter to ANT+ FE-C trainers almost exactly one year ago.
Your Thoughts
What about you? Do you think feeling the draft would improve the Zwift experience?
Note: I’ve sent this over to Zwift for comment, and if they chime in I will issue a follow-up post with that information.
Draft feel would be nice, but in a way, it’s sort of there. In the draft, to keep behind the rider, I have to lower the resistance manually by shifting one or two gear easier (whereas outside I’d be able to stay in the same gear, it’d just feel easier).
I think having the resistance change to make it more like outside would be a good thing, but I don’t know if it would change how the pack works. Would the pack calm down, or would riders end up shifting one (or more) gear harder and keep hammering? We’d have to try it to find out, I guess.
I would love it if Zwift decreased resistance when drafting. It just gets it that much closer to that realistic feel
How about Wahoo’s $10,000 fan cuts back a hair when you are in the draft along with resistance drop? That’d be some tactile goodness (though I might ride up front to get the airflow from the fan.
I’d support that! It should be doable…
How about making you just that bit faster when you are being drafted and the rider behind is pushing the pocket of aid behind you. That would also make it just a bit more like real life.
I’ve heard this argument all my life. No one has e er proved it. If 200 mph like NASCAR, probably. If semi-tractor trailers, probably. Not with bicycles.
I simply do not understand why Zwift do not attempt to create as realistic a sensation as possible. I realise that it is not possible to breake and stear as in real life, but still it should be possible to simply reduce the resistance when you are close behind another rider or a group of riders no matter your sideways placement on the road. This would be much better than the existing effect in my opinion.
Gert Munch
Yeah, you can change down a gear and effectively lower the resistance. IRL that would make you drop back – because your speed would drop, but your virtual speed shouldn’t drop if your trainer reports power at the lower gear enough to stay in the draft.
i.e in zwift the question you should ask yourself is “what is the lowest gear I can spin to stay in the pack” That will be a power figure too, 200 watts or whatever, but it’s you that controls the resistance with your gears (you could do it with lower cadence but I think you get a better saving if you’re spinning a gear that feels easy than if you’re just pushing a hard gear slower)
If you start to drop back IRL the resistance would increase automatically (because you’re in the same gear), but in zwift you have to up the gear again to increase it.
So it’s not exactly true to say that the resistance doesn’t change because of drafting – it’s just that you have to trigger that change yourself with your gears – if you don’t, well you’ll both be doing 300 watts and you’ll save nothing.
I think with the newer virtual gearing they could get this working (maybe they already have?), because there’s no particular link between virtual gears and your real life gears (e.g you can easily use the big ring or little ring on virtual shifting – there’s a bit of difference in feel, but the trainers adjust so if you’re climbing something steep the low gears still feel low even though you’re in the big ring on your trainer, or vice-versa)
So zwift could perhaps have things such that if a front rider is in virtual “gear 10” doing 300 watts his virtual speed is X. You behind him should be able to do 200 watts in the same gear 10, but the same cadence, and the effort / resistance feels a lot less and the speed should be the same – same gear, same cadence etc how it should be to do the same speed. Then if you drop out of the draft the resistance in that gear 10 should increase, just the same as if the gradient increased.
But I think you would hit issues if you tried to do this with real gearing because zwift and your trainer would have to match your IRL gearing and speed to the virtual world. The advantage the virtual gearing has is that it can do that (in fact it has to do that to work)
I just asked about this on Facebook and was referred to your article. I would think supporting this would be great for group rides. It is now really weird that you have to guess how much to increase your cadence to do a turn on the front of a group.
This should be possible with virtual gearing + cadence data.
At that point the trainer is doing a calculation and setting resistance based on the riding conditions and the ‘virtual gear’ you’re in. Well one of those conditions is whether you’re in the draft or not.
So it should already work now with virtual gearing. I mean with a virtual gear n, and the same bike, my bike should move at the same speed at 90 cadence right? And the only thing that should change is how difficult it is for me to keep that 90 cadence whether that’s 50 watts or 500.
If it doesn’t work like that then I’d say that’s a bug. If they don’t give the trainer the right data to lower the resistance then that’s a design flaw in whatever protocol the virtual gearing has imo.
Of course, not everyone is using virtual gearing but if it worked (or works) like the above then it would be an incentive for people to use it I suspect because it’d be a lot more intuitive to ride a virtual bike that went 30kph in one of its gears at a particular cadence and if you spin your legs quicker then the bike moves faster.
The obvious solution would be to display: maintain between 212-240 to stay in the draft
I’ve been on Zwift for 4 years. I have 40 years of training and racing experience in real life.
I’m going to say that I have NEVER experienced a draft (even a slight draft) when riding on Zwift. If I close the gap to a group ahead, there has never been a reward.
This has been disappointing and a prime reason that, for the past 4 years, I’ve been considering a different platform for my indoor training and racing.
Zwift doesn’t care if they’re more realistic or not. I read one comment from a Zwift development guy that drafting would result in sandbagging. Well, duh! Just like real life.
and they wonder why people lie about their weight. 🤪
Just popped onto Rouvy as a newb there. They’ve got a very nice drafting wattage and feel savings widget. Tells you the wattage savings, variable to position of rider ahead of you. The feel adjusts very nicely.
I would like to see Zwift make being in the draft more sticky that it currently is. Because you CAN’T steer, or brake, or feel the wind resistance, or feel the power output drop, I find my avatar constantly drifting forward, backward, left and right, putting me in and out of the draft. They already implement a working version of this with the coffee break. I suppose one of the things they want to avoid is automatically sticking a rider into a draft position when they are just trying to pass another rider. This could get quite annoying when riding through a group of 20 riders. So perhaps the draft doesn’t become “super sticky” until they’ve held a drafting position for 5 seconds or something like that. And for those who don’t want someone drafting them, or, as is already the case, want someone else to take a turn at the front, Zwift could utilize the F1 elbow flick to allow a rider to knock the person behind them out of the draft, usable once every 2 to 3 minutes