New Course Gradients

(Chris Soper) #1

Having some issues with the second half of the new course where the gradients seem to change too quickly for my Wahoo Kickr to keep up. Cadence and speed go through the roof on a descent and before I know it I’m pretty much at a dead halt before the resistance drops off back to normal again. Tried to watch the %gradient and seems to go from -6% to 9% and then back to 2% within about 5/6 seconds

(Eric C. (Zwift HQ)) #2

Hi Chris,

We have not experienced that in the office. What firmware version are you on for the KICKR and have you done a recent spin-down calibration for it?

(Mark Williams) #3

I had the same experience. It’s been fine on Zwift Island (which presumably implies it’s reasonably well calibrated) but I haven’t recalibrated for a while. I’ll do that soon. In a couple of locations the change was really quite jarring, to the extent that I’d be surprised if this was just down to calibration.




(Ryan McMullan) #4

Had a similiar experience with kickr and gradient changes on Watopia. I thought it might’ve been lag, as some users just seemed to fly up the hills/flats doing stupid speeds.

This was just after the upgrade.

(Brett Martin) #5

Same here. I think it is after a small drop into a switchback it goes from a steep descent to steep ascent quickly, about 2/3rds of the way in. Cant remember specifically where. I’lll check on my next ride.

(Chris Soper) #6

Firmware was upgraded last week to 1.3.32 and was perfect on Saturday on the original island and did a spin down after that ride, Wednesday was also fine but on the new island yesterday for first time and had it. Can look throughy strava as it will probably be easy to spot the spikes in the data. Think it was near the start of the ‘esses’ segment 

(Ryan McMullan) #7

Replicated again, just before the 5% kick.

(David Sack 50+) #8

Same here.  1.3.32.  Just did a spindown. Will do another to confirm.


(S C) #9

Having same momentum issues - didn’t realize this thread existed and accidentally posted same complications in another comment. I also have a Kickr 1.3.32 and do spin-downs every couple of rides.

(Christian Wiedmann [X] 50) #10

Me too - also on the 1.3.32 firmware. As far as I can tell, this is just an extreme example of the KICKR flywheel momentum issue.

Because the KICKR isn’t accounting for the energy going into the flywheel, power is very low going into the dip. When coming back out, all the power coming out of the flywheel gets added resulting in a huge power spike (I saw 600+ watts regularly at the first dip). This, combined with the slight lag in resistance adjustment means that riders slow down to a near stop on the far side of the dip and then get slingshotted out when the KICKR resistance gets ratcheted up again.

I used the feather powerup one time this happened - it was pretty funny how fast I accelerated when the resistance kicked in.

(Graham Lang) #11

Yes I experience the same thing on those short dips before descending to the end of the lap. There’s a drop in resistance when hitting the subsequent uphill followed by a sudden increase toward the top of the incline. I’m guessing that Zwift is having a tough time trying to simulate the effect of momentum gained from the downhill assisting in the first part of the immediate uphill.  

(S C) #12

FYI: Jon (from Zwift team) responded to this issue in my other thread with a possible fix coming soon. I’ll paste below. 

Jon Mayfield
 4 hours agoOfficial comment

I believe this to be two issues:

  1. Zwift didn’t properly implement momentum. We always suspected this, but the new map made it very apparent.  This has now been fixed and will be sent out in an update very soon.  

  2.  Totally separately, the KICKR seems so responsive to grade changes that it reacts quickly - and it also doesn’t seem to take momentum into consideration.   This is a tougher one to solve, but I have a small workaround that I’ll try and get in before the next update.   In the meantime, the fix to #1 might actually fix this too as your avatar rider wont come to a stop in the dip anymore anyway.