They replaced my unit and the new one was giving me the same issue. I then did the factory spin down and it has gotten much better. I still think it’s off by 20W or so, but I’m too fatigued with trying to solve the problem and have just accepted it.
2 Likes
I still have my core 1, so I’ve just switched over to that from the new core 2 - hoping wahoo gets this figured out soon with a firmware update. Its way too widespread of an issue to NOT require some serious tweaking of the product.
These things definitely have a mind of their own. Giving them a pep talk and a regular dusting seems to help. But what really does the trick—besides the app spindown—is the permanent auto-calibration. According to Wahoo support, the best practice is to briefly accelerate to 20 mph (32 km/h) before every ride and then let it coast down. I’ve been doing that every time now and—voila!—the old buddy is currently measuring within 0.5 to 2% compared to my Assioma Duos. I’ll keep dusting it just to be safe, though.
And because life with these trainers is just so wonderfully uncomplicated, I went ahead and ordered an upgrade for Christmas: a Van Rysel RCR. It’s brand new and boasts some shiny specs: 2,800 watts, 27% incline, a LAN port, and 1% accuracy. Obviously, those 2,800 watts are extremely important for a rider like me.
I actually wanted to order it weeks ago when the Core 2 wasn’t responding to my ‘encouragement’ yet. Then, when Adam from ‘Road to A’ on YouTube featured this exact trainer as a replacement for his own finicky Core 2, I pulled the trigger. Adam was absolutely thrilled with it.
The thing just arrived and it actually makes a high-quality impression. It has LEDs underneath that flash different colors depending on your zone—except in my case, they cycle through every color with every single pedal stroke. Basically a disco light show. How lovely. It’s also supposed to do downhill simulation, except… it doesn’t. Going downhill, the motor just won’t kick in. And it has LAN! That works, too, but then you can’t use virtual shifting anymore. But hey, at least it’s accurate. Accurately wrong, that is—a solid 8% below the Assiomas. AI tells me it’s probably running an old initial firmware. Possible, but the app isn’t showing any updates.
Since I’m officially done with spending weeks ‘coaxing’ my gear, the Core 2 is back up and running. Just don’t forget the dusting.
1 Like
A quick update here. Wahoo exchanged my Kickr Core 2 for a new one which had exactly the same power accuracy issue as the old one - 15%. I’ve checked it against a SRAM Quark and Favero Assiomos. Both are within 1% each other and 15% more than the Kickr accross a variety of wattages.
The Core 2 is going back and I’ve switched back to my Core 1 using the Assiomos for power. 15% lower is huge - I can’t tolerate that. Training with power is all about consistency - the whole point of Zwift for me is to train for road riding/racing so I need that accuracy across devices. Maybe it’s just not realistic to expect that level of accuracy on a 400 quid trainer?
One thing I did wonder is if there is better accuracy between a Kickr with a cassette vs a Kickr with a Zwift Cog. I can’t be bothered to test it after all this faff but I recall my Kickr Core 1 with a cassette reading close enough to the Assiomas where I’d happily use it for Zwift races if I couldn’t be bothered switching pedals.
3 Likes
On another note - I did solve the resistance issue. I’ve been racing on Zwift for years, ZRL etc. Common advice for racing used to be to turn down the trainer difficulty to 10-20% so you have to change gear less.
I did a bit of research and it turns out that trainer difficulty controls how gradients feel both up AND down. So if you’re using virtual shifting and you find the resistance is too much on descents, try checking your trainer difficulty setting and changing it to 100% and you’ll find it’s much better. You get so many gears on virtual and it’s so easy to change them that there’s no benefit having lower trainer difficulty for racing anymore IMO. Hope this helps some people!