Free Axle for Wahoo Kickr Gen2 (2018)

The first generation of Wahoo kickr has a fixed axle which does not allow the use of a slope simulator in games like Zwift. It also does not allow the use of true axel. I have created this instruction to solve the problem.

NOTE: For use with a true axel, you will need to modify the shaft design to the diameter of your bike's axle.

Credit to Jörgen van den Berg

This project was motivated by the desire to use the SIMCLINE slope simulator made by Jörgen van den Berg

https://github.com/Berg0162/simcline/tree/master/Wahoo%20Kickr

https://www.instructables.com/SIMCLINE-20-Easy-Simulation-of-Road-Incline/

https://www.instructables.com/id/SIMCLINE-Simulation-of-Changing-Road-Incline-for-I/

For the replacement shaft 

2 X Bearing 61702-2RS

Cold rolled steel for machining parts

For the extractor

2 X Solid steel parts for the extractor

2 X Threaded rod of at least 12mm dia.

4 X Nuts for the threaded rod

Some flat washers

90mm long thick wall steel tube ID min. 15,5mm OD max. 23mm

1- Remove nut with a 17mm wrench

2- Once the nut is removed, pull the cassette towards you.

Be careful not to lose pawls or leaf springs

Note: If you add a lot of grease during assembly, your Kickr will be quieter.

3- Remove bolt A and loosen bolt B to remove the tensioner and the strap.

4- Remove the drive wheel by pulling towards you to expose the shaft

I recommend using a tube so as not to apply force to the shaft end during extraction.

By using this method you won't damage it and can put it back if you ever change your mind.

The tube must be longer than the shaft, have an outer diameter smaller than 25mm and have a thick wall section

so it doesn’t deformed when pushing out the shaft. Great pressure will be applied on the tube.

Setup must be well positioned with the two bars parallel and an equal tightening force in the two screws.

Be rigorous in your assembly it will be much better for the extraction and you will not break anything.

Start by tightening each bolt alternately, giving no more than 2 turns at a time.

At the beginning you will feel that you have to apply a lot of force for the axle to start moving.

Tighten the extractor to make the axle travel the distance of 10mm NO MORE because the axle will press on the other side of the extractor. 

Gently extract the shaft until it free off.

Clean the inside of the housing with fine sandpaper to remove any burrs.

Align the new axle housing and mount the threaded rod with washers flat.

Screw in gently, making sure everything lines up properly without excessive force.

The face of the bearing should be even or come out very slightly from the cassette side.

Insert the shaft and the thin washer (0.010'' spacer)

Reassemble the sprocket, belt and tensioner.

Make sure the sprocket does not rub against the frame by pressing sideways and turning. If it is rubbing you must add 0.010" shims.

Reassemble the cassette.

To tighten the cassette, hold the end of the shaft with pliers. 

CAUTION do not overtighten as this could break the bearings or damage the shaft with the pliers.

The shaft should turn easily with little resistance

Get on your bike and have fun with your new wahoo Kickr climb capable