High watts/Low speed jungle

Entered the Alpe du Zwift KOM race tonight. Was averaging around 300w entering the jungle and all of a sudden I went from top 30 to almost last place. Sustained 250 for a while and pace went from 30mph to 8mph, while the rest of the field maintained speed. My trainer is calibrated as of this morning. Riding on normal wheels and the tarmac frame. Is this a bug? Anyone else have this issue? At 5w/kg and passed easily by people doing 1.5-2.

MTB’s are fastest on the dirt in the jungle, road bikes are slowest.

1 Like

Sure. But everyone else in the race was on road bikes as well and holding 30mph…

@Mike_Rowe_PBR @Paul_Allen I guess my question is in that race, what is the better approach? I got passed by 170 riders from cat A-D all on road bikes all in the span of about a half mile. Everyone slowed a little in the dirt, but it was downhill, and nobody dropped to 6-8mph. At a steady 250w (~4w/kg) I was getting dropped by everyone, including riders at 1.5 w/kg. No one climbed Alpe du Zwift in a mountain bike. You think this is just bike selection or is there a chance my app update caused it?

What devices and trainer do you use?

Saris H3/ATV/also use my Samsung Galaxy S10 for the companion app.

What wheel set did you use? Did you keep up when the virtual surface was paved?

1 Like

I think there are issues with the H3 and bluetooth right now, that could be the problem.

1 Like

Used ENVE SES 3.4. Yea pace picked back up on the tarmac. Just seemed to be a more drastic difference than others encountered. Saw others had climbing race (Meilenstein) wheels as well.

I had some problems with the H3 on the Samsung but seemed to be fine on ATV. Maybe that was it!

Here’s the power/speed data from Garmin (not perfect but illustrative. Speed (blue line) drops at the lava, power (purple) stays up around 200w-250w for a bit but pace drops to 7-8 mph. Then I dropped power it to test and the speed stays around 7-8mph at 120w. Power and pace go back up when the tarmac restarts just before the climb.

@Mike_Rowe_PBR @Paul_Allen today went on a group ride. 400 people riding around 2w/k. I averaged 3.5w/k and pace continuously dropped on tarmac today to 9mph, passed by everyone within 3 miles. I remembered that last week I accidentally turned into a steering beta. I quit one minute in. After that it’s when the problems started. Any connection.

Shouldn’t be related, have you power cycled everything since then? Especially the ATV?


Didn’t realize ATV should power cycle after updates. Tried it and seemed better on the off tarmac parts of watopia. I’ll try again in the jungle tomorrow. Thanks. Assumed something was wrong with my trainer.

1 Like

That’s good to hear @Andrew_Scott2, most Zwifters with Apple TV are force closing the app and powering the ATV off after or before each ride to get rid of some buggy behaviors.

1 Like

@Andrew_Scott2 hey Andrew, hope you are getting on well with you H3 and Apple TV - I experienced exactly the same issue on that route as you described. There is a Bluetooth-H3 bug which Zwift know about and are trying to fix, but it sounds like you found a work around! My workaround was to switch to my iPad and seams okay so far. Rest assured I believe your trainer will be absolutely fine (that was my worry too!) I think it’s just a bug from the last update. All best!

1 Like