Lin, I’m not sure what I’d be looking for. Those data graphs all looks the same to me.
I performed a test with the Wahoo Fitness app this morning, setting the Kickr to level 3 as the customer service rep suggested, and I’m actually getting that loss of resistance there as well. I dropped from 930w peak power all the way down to 570w while turning 110rpm. I think the trainer’s jacked. The circuit board has got to be faulty because it’s releasing the brake and easing resistance as soon as I apply power.
Are you sure there is actually an issue here? I mean, when you first start a sprint your power goes through the roof, but as you get up to speed the power will decrease unless you continue to accelerate. This is similar to (if your car has the ‘instantaneous MPG’ readout) when you punch the accelerator your MPG drops to the single digits, but as you get to a cruising speed the MPG goes back up again. There is a lot of energy involved in increasing speed, and less in maintaining it.
Nigel, yes, I’m well aware of that. But to be in 52/12 and turning at 110rpm and hardly getting 600w seems off. I know others that are in the 14 or 15 and getting closer to 1000w.
I’ve just been getting this situation the past few races. I’ll peak 1000+w then 7-10 seconds later all my resistance goes away and cadence goes out the roof. Like 145+. I’ve never had this happen but am sending a ticket to wahoo as it seems like a trainer issue not a Zwift issue. I ran my Vector pedals as power and it clearly shows cadence spikes and power just falls away. By no means did I ease up in the sprint.
Neil, I’ve found a workaround. My new tactic in sprints is to stay on the hoods and wind up each gear, dropping down a gear each time I feel the resistance start to fade. It’s working so far. Managed a 20 second best sustained power the other day.
So I did a factory spindown based on Wahoo’s suggestion. Also I did all their suggestions about making sure the KICKR isn’t trying to pair with anything else. It worked the first sprint I did then last night it spun out real bad again while also dropping to 0w I’d share the link to the recording but you can’t on here. I’m thinking it must be a mechanical thing with the KICKR. I’ll keep you posted though.
Things that I’ve done that might help are to use only ANT+. In fact, go as far as disabling your Bluetooth connection on your laptop, if that’s what you’re using. When you log into Zwift, make sure that the BT icon at the top left of your pairing screen is grayed out with a ! over it. Blue tooth connection, for some reason, has trouble on Zwift. Also, not sure what you have Zwift’s in game “Trainer Difficulty” setting set at, but I noticed most of my problems when I had it set to 0, so it would be like I was riding a flat course. I’ve since moved that to 40% and it seems to have help for some odd reason. I went through all this with Wahoo and it looks like they’re not passing it on to others experiencing the same issues. So I’m not sure if it’s trainer related or issues with the trainer communicating correctly with Zwift. One way to test thing is to use the Wahoo Fitness app to test your power and sprinting. That’s going to be the next thing that Wahoo support is going to ask that you do. (You’ll need your phone for this, and there shouldn’ t be any Bluetooth issues with that, just Zwift.) They’ll have you do a power ramp from something like 100w up to 300w, and then back down again. Do a few test sprints, and then forward them your .fit file to review. But whatever you do, if they offer a low cost replacement Kickr, do not send them your Kickr without them first sending you the new trainer. With all the crap that’s going on these days, deliveries could take months! I sent a Kickr back to them on June 12th, and it was on the truck for delivery a few days later, but then it went back to the FedEx hub in Atlanta where it’s still sitting undelivered to this day.
I don’t believe it is @xavier_nihilo . I will check the temp after a race here just to check, I keep our house around 73-75 and this is a new thing as of a few weeks ago, and it only loses resistance in big sprints at the end of races. I’ve had the unit since Dec. @Derek_Rush I’ll try going full ant+ and see if that has any issue. I’ve got my old rollers for back up which I might start using if this keeps up but I’ll definitely keep my unit if that’s where this is heading.
Hello! I am having the same problem you had in July - I actually had this problem in July as well and can’t for the life of me figure out how I resolved it, but I did. It’s baaaaack. Did you get a resolution? During my last two weeks of racing, my trainer would keep applying so much resistance that everything felt like an uphill climb! Actually, last night the ride felt like a constant series of 15 second hills - uuuuupppp and doooownn such that the resistance would increase at the same cadence on the same grade and decrease over and over in a maddening pyramid format. Any information you have is much appreciated!
I didn’t ever get a resolution, I’m waiting on my team bike shop for a warrantee. Still does the same thing every race when I open up the sprint. I get about 6-7seconda of resistance and then everything drops out and resistance goes completely away.
Linda, to be honest with you, I don’t think there is a solution. I’ve been on a few different Kickrs now, and each one seems to lose resistance a bit during a sprint. I’ve even gone out an purchased the new 2020 v5 Kickr, and the flywheel does the same thing. I just don’t understand how I can get that nice peak power over 1000w, but after three seconds or so, no matter how fast I’m spinning the pedals, the watts seems to plateau around 600 - 650w. There is no solution other than to somehow muscle the cadence up to 200 rpm or so.
Any new luck with this issue? I’m experiencing a similar thing with my new KICKR Core. I max out with around 1000w in my 50-11. I’m able to produce over 1200w in the 50-14 gear in other training apps.
I actually went out and bought a new v5 Kickr. But it turns out that it’s not the trainers, because I’m still experiencing the same thing. This is on Zwifts end, whether they admit to it or not.
