Meetup Speeds Incorrect with Small Groups

Rode a two person meetup this morning and the speeds for climbing the epic kom were way too fast. Has anyone else experienced this? We were almost yoyoing past each other every moment.

Haha Wesley, I had the opposite experience on a Meet-Up ride this morning (May 10). Three of us were riding on a 0% grade road in Watopia and with a wattage of 200, our speed was only 16 kph!! That existed for about 3 or 4 km then, surprisingly and without reason, it went up to 46 kph which was probably the correct number.

Interesting - we definitely started with the 16 kph at 200 plus watts but then we were getting 46 kph going uphill at 5-7%. Embarrassed because it gave me a KOM crown despite riding at 230 watts. The “keep us together” function is a little bit weird. Thought it would let the person at the highest w/kg be the leader and then others could draft with a strong elastic

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Yep, I had the opposite too. Stuck at 17 kph until I ended the workout. Thankfully that didn’t reset our mileage or anything, but it did solve the problem. But then we were not necessarily together like before.

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I have noticed this before but today I payed attention to it.

We were 2 guys in a meetup with keep together on and our speed got stuck at 46km/h (29mph). I have steering enable so I don’t know if that has something to do with it.

The screen shot show us going up the KOM at 46km/h (29mph) while only doing 240w

I’ve certainly had this issue many times. It seems that the algorithm really struggles with small groups. If there’s just two of us in a keep-together meetup then it’s pretty common for me to see this issue at some point on the route. Usually it resolves itself when the terrain changes significantly, e.g. getting to the top of a climb.

Going too fast is amusing, but the opposite happens too and It’s very frustrating to get stuck pedalling through treacle for a while.

It’s not a steering thing (I don’t have steering).

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I’ve created a couple of meetups over the past two weeks. I’ve noticed when i’m climbing up grades of 5% and over, my speed and that of other riders are ridiculously fast, like 40km/h and faster while my watts per kilo is between 3-4w/kg. Then on descents, my speed sometimes barely reaches 30km/h. It’s almost like my rider weight is reset to 40kg, or something like this.

Can this be looked into?

I had a classic example of this issue this morning.

I’m running on Apple TV, app version 1.0.57547.

I was in a Meetup (keep together and meetup-only view, 1.5 hours duration, Royal Pump Room 8 course on Yorkshire) with two others, so there were three of us in total. All was working fine with us staying together and the terrain affecting our speeds in the normal way that I’d expect. We are all roughly evenly matched in terms of the other two being slightly stronger than me but not by a lot, and typically our w/kg are all quite similar (ranging from around 1.5w/kg up to just short of 3.0w/kg when we’re pushing it).

After approx 1 hr 10 mins one of the riders decided to end his ride, and two of us carried on. Pretty much straight away the speed started to go way off from what we’d expect. The course is mainly downhill and uphill with very little flat, but we found ourselves going downhill at around only 15mph, and uphill at an unfeasible 29mph, while outputting a similar power level throughout.

This is the same sort of behaviour that I’ve been seeing for several months now on keep together meetups with only two riders, though it never happens for the whole of the ride - it comes and goes.

It’s far from a new thing. If there had been flat sections today then we’d have probably found ourselves going unfeasibly slowly sometimes there at high power levels (because that’s what I’ve been seeing on other similar meetups with two participants), and it’s super frustrating when that happens because it then takes a very long time to go a short distance). But today we saw the uphill/downhill speeds go wrong almost as soon as we changed from three riders to two.

There seems to be something wrong with the keep together algorithm when only two riders are present, and it sometimes acts like you have an invisible flyer off the front when going uphill (towing you forward), and an invisible very slow rider behind you when going downhill or on the flat (dragging you back).

Zwift, please have a look at the server-side logs for my ride today and you should be able to see this pretty easily in the latter 20 or so minutes of the ride. Being on Apple TV I don’t have any accessible logs that I can send you.

@Wes @Shuji_Sakai ?

Thanks.

Steve thank you for sharing this - further confirmation that they haven’t figured this out. I do think it’s an important growth opportunity for them - two people teaming up for any distance is an organic way to grow community.

Wesley Ng
Penn Women’s Rowing

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It would be interesting to know the no-drop algorithm. One reasonable approach would be to apply a speed delta proportional to and in the direction of the distance from the center of the group. This algorithm would not exhibit this sort of anomaly. No need to decide who is in front.

Hey,

We are having the exact same issue. Speeds stay at 45kph for 15-20mins no matter the power or uphill/downhill and then suddenly drop to 15-17kph (for 15-20mins) again no matter the power or downhill/uphill. After this slowing down, the speed goes back to 45kph. The speeds are nearly constant, power does not have an impact on speed. Two people, both outputting around 2-3w/kg. Problems started last week. We have noticed this in four different rides.

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We got the cone of shame and got booted out of the meetup because Zwift has our speed to high.

LOL :rofl:

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