Saturday 02 May 2020
My 2014 Wahoo Kickr 1st Generation smart bike trainer developed a strong smell of burning electronics after my second ride up the Alpe Du Zwift earlier this week. Normally I only use the smart trainer in the winter months and cycle outside once it gets warmer but with the current lockdown, I haven’t been outside on the bikes for a few months.
I stopped riding but the trainer’s flywheel was too hot to touch and there was a smell coming from the air vents which smelt like burnt electronics.
As the Wahoo Kickr is around six years old and well outside its warranty period, I decided to try to take it apart to clean any dust build-up and see if I could find the source of the burning smell and fix it if possible.
To access the internals of the Kickr, I first removed the belt cover which are held in place using two small philips bolts and three 2.5mm hex bolts. You can see a video of this step and belt adjustment on youtube.com/watch?v=Rpxb3iPU-iM
This gives access to the belt and the belt tensioner which can be removed by loosening the 2.5mm adjustment screw on the side and removing the 5mm hex bolt.
The belt can then be removed, and the tensioner pulley and bracket removed giving access to the rear plastic belt cover.
There was a lot of dust build-up around the pulleys and this was removed before moving onto the rear belt drive cover.
The rear belt cover is held in place with two 2.5mm hex bolts onto the metal frame. Removing these allows you to remove the cover and access the hex bolts holding the plastic flywheel covers in place.
The flywheel side has two plastic covers with the top cover having air vent holes and the lower cover with the model sticker covering the small control circuit board.
There are three 2.5mm hex bolts on each cover and these can be removed with the belt covers installed but it is much easier to access the bolts with the other covers removed.
After removing the covers the top section has a number of air vent holes which lead to the coils inside the flywheel and the PCB on the lower side has three connectors going to the power input, the top reflective sensor and the coil.
I inspected the control board circuit and there did not appear to be any damage from overheating.
I cleaned the dust from this side and then moved onto how to remove the flywheel to clean inside and check for any problems.
There are several videos online showing the removal of the flywheel by holding the drive belt pulley with pliers and unscrewing it and then hammering the shaft out of the bearings to remove the flywheel but after looking at the flywheel side, we found that the centre had a flush fitting plastic cover which revealed a 19mm nylock hex nut.
The nut was removed but the flywheel was very tight on the shaft. It was removed by holding the pulley and gently tapping the shaft with a piece of wood and a hammer. The pully shaft also has a small metal keyway which can fall out so take care not to lose it!
Under the pulley was a set of large coils and a single cable going to the control PCB behind. There were signs of burnt dust on the coils which must have been the source of the burning smell.
The coils are held in place with three 5mm hex bolts and after removing these the coil assembly was removed and cleaned.
Once everything was cleaned and the trainer was reassembled, I ran a spindown initialisation using the Wahoo app on the phone and it then worked correctly again with Zwift.
I was considering buying the latest version of the Wahoo Kickr as it is supposed to be much quieter and doesn’t have the vibration issues which mine has but no one has any in stock at the moment and when they come into stock they seem to sell immediately.
Hopefully this clean-up will keep the Wahoo Kicker running for a few more years.