This is the eight week “in use” review of the Kickr Core 2019. This is a follow up to the unboxing review.
The $900 training tool
Most of us into cycling have heard of the Wahoo Kickr smart trainer. A lot of us know that these can be expensive toys or serious training toys that are beyond our reach. Wahoo have numerous products in their line at different prices, the Kickr Core is positioned as one of those “mid” point toys, a step down, not super expensive but still expensive. This mid landscape of smart trainers seems saturated with $599 to $899 products, so this falls on my product radar to judge the value of.
Marketing is good, but the motivation for a $899 trainer has to be pretty strong. In general indoor trainers are driven by a goal, it might be unspoken and as simple as staying fit, or as specific as training for road race season to gain your cycling power. My motivation was to keep some fitness and improve my power.
Eight weeks on the Kickr Core
After having some time on Zwift and a session on SufferFest, I signed up to Trainer Road an online fitness plan to keep me on track and guide me through some workouts while I test this Kickr Core.
The days of jumping on a trainer, settling into the monotonous rhythm of spinning your legs are gone. Thank goodness, because those were some boring hours. There are many training software to assist you with a method to help your indoor riding motivation. The big ones are Zwift, Trainer Road and Sufferfest.
Set it and forget it – the Beauty of ERG mode
Set it and forget it. Automatic resistance.
If you are buying a trainer to have fun on or train seriously or even somewhere in between, smart trainer is for you.
A smart trainer automatically adjusts the resistance based on how hard the computer program wants you to ride – Erg mode. I know, a rather silly terminology, but it basically means automatic resistance. When in ERG mode you only need one gear the computer and trainer do the rest, no more shifting. The Kickr Core measures Power and Cadence automatically. * – see note at end of review
In a program like Zwift it means the resistance will change based on the terrain. Go up a hill, yeah it gets harder.
In a program like Trainer Road, as you hit workout blocks, the resistance will increase based on the the workout you are doing and where in the workout you are.
The feel
There are a couple of things that determine the feel.
First is the changing of resistance, you might describe the worst situation as feeling abrupt changes. The Kickr is smooth and transitions very nicely between different resistance settings, if you are highly perceptive you can feel a lag between the software and the trainer but I would say this is less than 1 second and in most cases you will not notice. I only noticed when jumping from 100W to 400W. If you software simulates transitioning into rolling hills, you wont notice a thing. (see note*)
Secondly, Inertia and resistance. On a real bike the wheels and the drivetrain have inertia (resistance to acceleration or deceleration), there is also resistance of the road that is felt by the rider. On a trainer, this is simulated by a flywheel which stores rotational energy. The key to good engineering is figuring out a good flywheel mechanism to give the most realistic feel. Wahoo has nailed this. I have ridden trainers with bigger flywheels and ones with smaller ones. I do not know the spec but if I were to guess I would say its somewhere in the region of a 13lb flywheel.
Technically the size of the flywheel also limits the maximum wattage a trainer can handle and the core is rated up to 1800watts, which let’s be serious is plenty.
| KickrCore 19 $899 | |
| Type | Direct mount, remove rear wheel |
| Metrics captured | Speed, Distance, Power, cadence |
| Connection | Bluetooth or Ant+ |
| Folding | Partially (see photos in this review) |
| Cassette Supplied | No |
| Max Wattage | 1800W |
| Axles | 130,135,12×142, 12×148 included. |
Positives
Having just finished 8 weeks of riding and a lot of hours on the Kickr Core now’s a good time to give some feedback.
- The unit is very stable, much more than a wheel on trainer. The bike feels locked in due to the quality and construction of Wahoo’s metal frame. This is nice and gives you a feel of confidence when riding hard.
- The trainer is easy to set up and easy to connect to your computer or your tablet. It connects via Bluetooth or ANT+
- Sometimes electronic devices clash, but not in this case- heart-rate monitors, cadence sensors all work seamlessly with this trainer. No issue pairing or messing around.
- Works great with all software training platforms.
- Very Quiet, theres a high probability here that your drive train is noisier than the trainer. It’s really that good.
Negatives
- Stopping a workout / ride during a higher power section can make getting back and pedalling the bike really difficult. Like stopping on a hill in a high gear. This is somewhat to do with the program setting the resistance but also to do with the gear you have selected*, since you still need to get over the inertia of the flywheel. The way around this? im not sure I will have to do a little more research to find out.
- Expensive! but worth it?
- Expensive
Which gear should I use with my Kickr?
* Since ERG mode doesn’t require shifting (automatic resistance), then which gear do you set it in?
I found that using big ring on the front and middle of the cassette on the back gave a good balance for experience
If I used the small chainring on the front I found the initial cadence was too high but I could easily get over the inertia of the flywheel and the trainer would shift quickly to different loads. If I used the large chainwheel (52t) and middle of the cassette (17T) I found the cadence feels right in the powerzones and also the trainer can still change resistance quickly.
The other reason for using a gear in the middle of the cassette is rather nerdy and marginal gains – The chainline is closer (straighter) in the middle so the chin makes less noise and theoretically lasts longer.
The motivating graphics on the fly wheel are pretty faint, normally it take a lot more than this for me 🙂
Summary
I approached this with the perspective of someone who has not come from direct and recent experience with “smart” trainers or high end training tools. Sure I have had a few trainers over the years, hibernating over winters in Chicago pretty much requires trainers. Typically I have used the type of trainer or rollers where the rear wheel contacts a drum that provides resistance. In the past this resistance came from magnets, fluids and other mechanisms and it was non interactive – Set it, ride it. Nowadays with the advent of more advanced electronics we have software like Zwift and training applications like Trainer Road and Sufferfest, these can communicate to the trainer so it can set the resistance based on the software. That’s the “smart”. This is useful for fitness based entertainment aka gamification but also for training, power, intervals and sweet spots in the traditional bike racer sense.
If you are going to dedicate time to your cycling indoors and you can afford this option then do it. The unit will not let you down in achieving your fitness goals. It is high quality and no messing around, leaving no excuses not to use it. Setup is easy and measuring power and speed is a breeze. Of course you are going to get the best use out of this if you use programs like TrainerRoad or Zwift but it can be used in other ways via a compatible head unit.
For the most part I used my training with a laptop, but you can use your tablet, smartphone or compatible headunit. I found it easiest with my laptop but have used it several times with an iPad.
Which software should I use? thats a whole other subject, for now I’m going to leave it untouched but I will say there are free trial periods on all platforms so you can explore and find what meets your need.