Bike Bias for Ride events

For ride events that aren’t races, would a +% bias selector option to adjust difficulty to make harder to maintain speed be worthwhile? Would sorta be like doing an instant change to deflated tires, or donning a flapping-in-the-wind poncho.

I could see value for those who want to do a social/group ride, but want to, at times, add some difficulty to the advertised wkg for themselves but don’t want to go off the front (which is often frowned upon). Would be similar to the bias setting that already exists for training workouts.

What about just changing to a gravel bike or MTB?

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Lots of requests for this already:

Riders have been known to change their weight for this purpose. Of course this can only be done before the start and can’t be adjusted on the fly. It’s also embarrassing if you forget to change back prior to a race…

Couple reasons, it might not be as precise, and there’s difficulty or time required to do it mid ride. Bias would allow to go up and back down when you feel like it during a ride. Likewise on a MTB course and riding a MTB, the bias option would be there as well.

Yes, that sounds similar, but root reason for that request was users who are running out of high gears and can’t get to the wattage and therefore speeds that they want to. This request is for a given wattage to yield slower speeds.

I feel like it would accomplish the same thing, more resistance so you have to put out more wattage to go the same speed.

Or just choose the slowest bike and wheels in game as Nigel suggested.

Yes, but the other thread they wanted more resistance so that they wouldn’t spin out and could go faster. This is about more resistance (wattage necessary) and not going any faster.

Switching bikes is imprecise and time-consuming during a ride.

My simple mind still thinks we are talking about the same thing…

increase resistance so I’m on what feels like a 1% incline while the rest of the group is on flat road, I have to put out more power to maintain the same speed.

increase resistance so I don’t spin out using a lower gear ratio bike, I now have something to push against so I put out more wattage and go faster (compared to spinning out).

but it does accomplish what you are asking for

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No, not really.
The example situation: You’re a B riding 3wkg type. Looking for a group ride. Find an interesting one that’s at the time you want, but it’s a 1.5wkg D ride. Simple solution – join the ride, but set your bike bias at 200% so that when putting out 3wkg, you’re only doing the speed as if putting out 1.5wkg. Someone who wants a 2.5wkg ride would enter 167% bias for that same ride. Etc etc… infinitely customizable to make any offered Zwift group ride exactly the difficulty you want and you can stay with the group.

Alternate solution - we offer more variety in the form of additional pace partners and ensuring there are group rides for all abilities rather than those predominantly centre around D (and a bit of C) pace.


That works too! Pace Partners are great, though they don’t currently exhibit a realistic swing in power for uphills vs downhills. More non-race rides is ideal, but you need more humans to organize and lead. A ‘bias’ setting would seem to leverage in a similar way, the tech capability that Zwift already has in place for Training rides.

A bias is an interesting concept, it will be like adjusting your weight so you go lower for the same power.

I don’t think many will use it since they don’t like to go slower (thinking back when Zwift introduced higher rolling resistance for gravel roads in the jungle).

Mountain bikers ask for this not long after they first find out what its like to run out of gears.

I think you are thinking about the request for more base resistance. That is different.

The OP is asking for the ability to go slower at the same power.

Ie: normal speed at 230w = 40km/h

10% bias then 250w = 40km/h

Yeah I was - my head went straight to the bias button in workouts that could be used for all resistance use cases (without explaining myself :slight_smile: ).

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It might be easy to think about it as similar to adding weight, but this solution would be much more tunable and would keep standard Zwift dynamics in place. Changing weights or bike types wouldn’t work as elegantly or for that many circumstances.

An example, using the prior example of the 3wkg rider who wants to participate in a 1.5wkg ride. If rider is 150lbs, in order for weight by itself to bring down the 3wkg rider’s speed to the same as a 150lb 1.5wkg rider on flat ground, I think they’d need to change their weight in Zwift to approx 800lbs. And then hitting even a 3% gradient, that 800lb rider is likely to be crushed.

I was just simplifying the request to point out the difference between the baseline bias that people has been asking for and your request for a speed bias.

We used to adjust our weight so that we could do workouts together. So it is not that crazy idea.

Not really if they keep the same w/kg. The whole point of w/kg is to equalize riders on climbs.

A 70kg rider at 1.5w/kg 105w will do 26km/h on a flat
A 100 kg rider 150w will do 31km/h on a flat

so the 100kg rider has to adjust his weight to 234kg to be the same speed as the 70kg rider.

234kg @ 3% = 8km/h
70kg @ 3% = 12km/h

Not sure what you’re saying since you’re netting out with the 2 riders going different speeds and they’re not equalized?

A “D Cat” 70kg rider + bike at 1.5w/kg or 105w will do 25km/h on a flat
A “B Cat” 70kg rider at 3w/kg will be at 210w and do 32km/h on a flat

The “B” rider has to increase weight to about 350kg to ride at 25km/h

At a 3%, the “D Cat” rider will be going 12km/h
At 3%, the B rider with the 320kg weight will be going 5.8km/h

Forget about downhills, the 320kg B rider will be doing about 30km/h faster on a 3%.

If the general idea is that any rider ability could sign up for a ride and stay with the pack (thru the ups and downs) while riding to their own ability, a wattage bias would work a lot better than futzing with weight entries.