Starting from a stop takes *forever*

I have a Kickr Snap and during the trial I was pretty pleased however this is one thing that doesn’t make sense.  It takes a lot of hard pedaling to get up to speed - way more than I feel it should on level ground.  What’s going on with that?

I can’t say I have noticed this myself.

I’ve logged 500 Zwift miles on my Kickr Snap and never experienced what you describe.

Have you performed an Advanced Spindown?

Do you perform frequent regular (not Advanced) spindowns?

Do you have other bluetooth and/or ANT+ apps running during your Zwift session?

What firmware version is installed on your Snap?

I have not performed an advanced spindown.

I perform standard spindown before each ride.  I warm up myself and the tire using the Wahoo app for 5-10" before spindown.  Then I close the Wahoo app and fire up Zwift.  Standard spindown takes around 12-14 seconds with my tire tension set to avoid slipping on the Richmond hills.

I do not run other apps.  My Garmin is powered off, and I close the Wahoo app that I’m running from an iPad mini.

Latest firmware, updated last week.

I guess the thing that doesn’t make sense is I can into the big ring and get my cadence up over 90 pretty quickly, but my virtual speed slowly goes up.  I suppose I could turn on my Garmin, set it to forget my cadence and HRM, and compare my speed in Zwift to the Garmin speed.  Then I’ll see how much of this is in my head.

The most likely cause is failure to perform the Advanced Spindown. Takes 5 minutes. It was only available on the iPhone app for a while but maybe it’s available for Android now, I’m not sure.

AFAIK there was no firmware update “last week” so, unless you mean that’s when you first used the Snap, I wonder if we’re talking about the same thing. The latest released Snap firmware is version 2.0.28.

As I’m sure you know, virtual speed on Zwift is AFAIK completely a function of power and terrain grade – at 200 watts on the flat you’ll go quickly; on a climb much less so. So your Garmin speed will often (usually) not correspond to the speed you’re seeing in Zwift. Garmin speed is measured by (a) GPS or (b) wheel speed. Not by power.

I’ve noticed the same thing as well.  Starting out, it seems like it takes a bit of riding through molasses before I build up any sort of speed.

Same here. Kickr. Haven’t performed an advanced spindown (never seen the option), but I do spindown regularly. On Watopia I don’t reach speed until the start banner (isn’t that like a quarter of a mile?). On road with a similar effort, I’d be there in 3 seconds.

Same here. Kickr Snap. I’ve done some of the races & the for the ones that have a sprint start I’m left behind. I don’t know if it because of the big flywheel? Have you noticed when you hit the base of a hill your power spikes & you roll past other riders, but going over the top of the climb, it’s the opposite, they go flying past you as it takes you  long time to ramp up speed again.

Yep. Current behavior is much better for the short KOM attempts I suppose. I think turning down the “difficulty” slider might improve this behavior, but on the other hand reduces the smart experience.

For those of you who notice the same thing, are you also dealing with dropouts / lost signal of power?  When I first reported the slow startup thing, I hadn’t tried a workout.  Now that I have, I can see I’ve been losing signal frequently.  I’m trying to solve this problem, making limited progress.  Just wondering if they might be related.

Nope, dropouts are incredibly infrequent for me. Like once every few weeks. I’ve got a USB extension so my dongle is basically right next to the trainer. 

Don’t think dropouts are the problem here either. Dropping the zwift “difficulty” setting from ~50% to around 25-30% did improve the group ride/race experience though, Makes it a bit easier to stay with a group, at 50% I would go off front at start of hill & drop behind descending. It might have slightly improved the standing start also, not sure yet. I’ve been told a real power meter improves instantaneous power response for sprints.