Kickr Snap Speed and FTP


(Nick Fear) #1

Last winter I used a Cyclops Fluid 2 trainer and rode on zwift.  My calculated ftp test around 205 at the beginning of winter last year.  This summer Triathlon races went pretty good and averaged 23-24mph every race. I now have a Kickr Snap and I did an updated ftp to get ready for this winter.  I tested out at 154 ftp.  Crazy low compared to where I think I was or should be.  Also outside if I go on a 30 mile ride I can avg 20mph fairly comfortably but zwift really pushes me to try and maintain that.  Any thoughts or suggestions.  I have done some of the spin down suggestions.


(Bastiaan Gaillard [HIK - C]) #2

Hi Nick,

The trainer you mention is a classic trainer and in Zwift based on zPower. This is only estimated power.

https://support.zwift.com/hc/en-us/articles/203152565-Which-trainers-does-Zwift-support-

There is a good read from Zwift regarding zPower:

https://support.zwift.com/hc/en-us/community/posts/202148759-zPower-Don-t-be-a-Flier-

I have read some posts from people on the Zwift Facebook group that mention your old trainer and have gone to a new power based trainer. They have seen big differences as well. 

https://www.facebook.com/groups/zwiftriders/permalink/560424160830560/?match=enBvd2Vy

Hope this helps. #rideon


(Allan Scott) #3

Have you done both types of Spin downs? If you have that much of a wattage discrepancy that could be the problem.


(Nick Fear) #4

Thanks.  Huge difference tonight.   I warmed up on trainer for 10 mins.  Then I did both spin downs in the wahoo fitness app and not the wahoo utility app.  did it multiple times.  Went for a 40 min ride at a comfortable hard pace and averaged 22.6mph and swift said we have updated your ftp to 211 when I was done.  So I will retest later this week and see where I am at.  I feel much better about it now.  How often should one do the spin down test.  Every ride or just when noticing some discrepincy.


(Bastiaan Gaillard [HIK - C]) #5

Hi Nick,

Good to read everything seems to work fine now.

How often you should do a spin down depends on how often you use the Kickr and for how long. I am using mine every week a couple of times and do a spin down once a month.

Good luck with your next FTP test.


(Michael Shirey) #6

With a Kickr Snap you do the 2 advanced spin downs when you first use it out of the box. The normal spindown should be done before every ride to check wheel tension on the roller.