Group rides and watts per kg?

Regarding zwift and group rides. If the power for a group ride is said to be between 2.0 and 2.2 watts per kilo. Can you really say that and keep the group together? As I understand it two riders of different weight will not have the same speed if both put out 2.2 watts per kilo or is that accounted for in some algorithm?

Always a conundrum and unknown since pure watts isn’t part of the listing. A 2wkg ride for a 60kg leader is 120 watts. However if the ride leader is 90kg, 2.2wkg would mean ~200 watts or 3.3wkg needed for a 60kg rider.

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Some group leaders will announce their weight at the start of a ride to give a better idea of pacing.

Neither raw watts or w/kg is a perfect measure, but I think that w/kg is better than raw watts.


It doesn’t have be an either/or, but could be that both should be supplied. Though I guess that might offend some since then it’s possible to calculate the leader’s weight.

Not against the idea, but for rides where multiple leaders/sweeps are listed it becomes a bit of an administrative nightmare from an event creation point of view.

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Would’nt it be better to say that “We will have a pace of 30 km/h average” that is what you would say in real life so to speak.

I’ve said this before but Zwift knows how fast you should be able to ride. They wrote the formula which takes into account your height and weight to work out your drag coefficient and they know exactly how fast you could ride at any particular wattage.

Imagine if Zwift used the w/kg of an average rider in the event descriptions. Zwift could calculate how fast that average rider would travel for any particular w/kg and Zwift could also calculate how much power you would need to travel at the same speed as that average rider.

So, in addition to the w/kg range (for an average rider), imagine if the Companion app or the Zwift events page listed exactly how many watts you’d need to ride. Something like “You will need to average 217w to ride with this group”. Everybody’s watts would be different but it can be calculated (again, Zwift wrote the formula so they can work out how fast the average rider would go and how much power you’d need to match them) and displayed. And if you really wanted to be clever it would take into account the elevation of the course. Lighter riders would need more watts on a flat course than they would on a hilly course.

If events had multiple leaders/sweeps listed, then they could just look up how many watts they need to produce to ensure that the group rode at the same pace week after week regardless of who the leader is that week.

It would take the guesswork out of signing up for events when you know exactly how many watts are needed. This is the magic of computers, this is the kind of stuff that computers do brilliantly. I’m not saying it’s easy but it’s certainly doable by a competent programmer.

Fun to speculate but it’ll never happen though. Zwift is Zwift after all.