Wahoo Kickr Core: Introduction

In normal times, indoor bicycle trainers are not hot sellers. They are usually used only when the weather makes it impossible or unpleasant to cycle outdoors, such as areas with cold winters.

However, amid the ongoing global pandemic, indoor bike trainers have surged in popularity. Due to the severe limitations on outdoor cycling (and most forms of outdoor activities), cyclists are finding ways to continue cycling indoors. This sudden surge in demand for bike trainers led to them being sold out everywhere, in stores or online.

In the first place, bike trainers are not items with high stock levels, as they move really slowly. Now, with many people looking to buy them, even stores with substantial stock (>10 units) will run out of stock very quickly.

I am also one of those who want to continue cycling indoors, which is why I found a way to make my Cervelo Aspero fit on the Minoura LR340 Bike Trainer. However, I am not a big fan of wheel-on-roller bike trainers, or in other words, dumb bike trainers. That is because there are various downsides to these kind of dumb trainers.

Disadvantages of dumb bike trainers, compared to direct drive bike trainers:

1) Noisy.

2) Heats up fast.

3) Gives off a burning smell from the heated tire rubber.

4) Very high wear rate on the tire (unless you use dedicated bike trainer tires).

5) Sheds rubber bits from the tire as it wears out.

6) Riding characteristics differ greatly from actual road riding as the rear wheel cannot freewheel properly or carry momentum.

The Minoura Thru Axle Adapter is just a temporary solution, while I find a better long term solution for a direct drive smart bike trainer. Although I tried to buy a direct drive bike trainer in early April, it was already too late, as there was no stock of direct drive bike trainers anywhere.

My only option was to place a pre-order and be patient. I was given an estimated delivery date of end May, which is the earliest date I could find. This is for one of the highest rated direct drive smart bike trainers, the Wahoo Kickr Core. This decision was no doubt helped by the super detailed review by DC Rainmaker.

The feature that really stood out for me was the low noise level of the trainer, which is really important for me. Being a direct drive type was also critical, in order for a more realistic ride. For more details, you can check out the review by DC Rainmaker, or read on below for a more simplified version.

This Wahoo Kickr Core actually arrived ahead of schedule, in the middle of May. I was expecting the delivery schedule to be delayed to June, due to the production and logistics difficulties around the world. It was a pleasant surprise to receive the Kickr Core early, as it means more time to use it!

The Wahoo Kickr Core is here! It is a big and heavy box.

As a direct drive bike trainer, it replaces the rear wheel of the bike, which I think is a great system.

You get lots of power cables, to fit the power sockets of every region.

In Singapore, this is what we need. The power adapter is shown on the left. Yes this smart trainer needs to be plugged in, unlike dumb trainers which are not powered.

Main trainer unit all wrapped up, as it still requires some assembly.

It is important to connect the smart trainer to the Wahoo app for some updates.

Here is the freehub body! Standard Shimano splines, for 11 speed road cassettes. The cassette is not included.

Here are the legs for the bike trainer. The long one attaches to the front, while the short one is attached to the rear.

Lots of small parts and adapters included, plus the manual.

4 bolts to attach the 2 legs to the main trainer unit.

The hole on the trainer legs are actually square holes, which is unusual.

The square hole matches to the square head of the bolt, to prevent rotation during tightening of the nuts.

Bolts are inserted from the bottom, and are tightened with a nylon lock nut on top.

The nuts are covered with a black plastic cap, for better appearance and to prevent rust due to sweat.

The adapters provided by Wahoo will cover most conventional bikes. The steel QR axle is also provided.

Self-explanatory graphics, very easy to understand. Adapts between 130/135 mm QR type, or 

142/148 x 12 mm thru axles. 148 mm means you can put your Boost spec MTB on this bike trainer!

As always, tighten the QR axle or thru axle fully and securely.

And here is the secret to the quiet operation of the Kickr Core. A new belt drive system that lowers the driving noise compared to previous models.

The cylinder with the arrows is the flywheel, and that is what makes this whole bike trainer so heavy.

Kickr Core assembled! Driving the freehub body will move the belt, which rotates the flywheel via a pulley ratio that makes the flywheel spin much faster than the cassette.

According to the manufacturers of direct drive bike trainers, a bigger flywheel is an advantage as it can replicate the road riding feel more realistically. However, this also makes the whole bike trainer really heavy, as there is a big flywheel attached to it. If you need to move the bike trainer around often, it will be quite inconvenient.

Wahoo Kickr Core weight as measured: 19 kg without cassette

I also checked out the freehub body, to determine the engagement angle. Normally a smaller engagement angle means a shorter lag time between pedaling and the wheel actually moving. However, it also depends a lot on the gear ratio and also the type of usage. For me, 15 degrees or less is sufficient for on-road riding, while for off-road riding, it needs to be less than 10 degrees.

The freehub on the Kickr Core has a 15 degree engagement angle, or 24 clicks per rotation of the freehub body. The actual points of engagement is unknown, but it is most probably 2 points of engagement, as this is usually sufficient for strength.

So far I have set up the Kickr Core, and it was easy. The adapters are easy to identify and swap. Next step is to install the cassette, attach a bike, and connect it to an app for some indoor riding! Watch for the next blog post where I will show how I attach my bikes to the Kickr Core.