Last winter I started cycling with the super light Exustar pedals that are compatible with the Shimano SPD system for MTB shoes. This despite the fact that I prefer the Speedplay Frog pedals. It's just more convenient at my work at the Ligfietsgarage Groningen to walk on shoes with an SPD system. I don't have to change shoes when I have to test ride a velomobile or a recumbent that has been serviced. There is nothing like a testride when you want to know if everything is ok with a bike.
Anyway, the pedals seemed to work just fine, but something was very wrong with my Mango. After about 30kms' of riding the velomobile started to squeek louder and louder, up to the point that I dreaded having to push the bike home. That never happened, but the noise was excruciating enough to want to fix it right away. The problem was that despite my years of experience with building Mangos', I couldn't find anything wrong. I started to exchange the Mid-Drive, which was due for a change to test a lighter one anyway. The noise didn't stop..... Every long ride the noise came back. In order not to take the bike apart completely, I started thinking what I changed to the Mango.
Since my Mango is sort of a testing bike, I make lots of changes to it, but the one thing that stuck to my mind were the new pedals. I took them out.... the noise was gone. Put them back in..... the noise was back! How could this be? The pedals were running ever so smoothly when I had them in my hands, yet started to squeek very loud after a bit of cycling.
Then I remembered that the DualDrive, which is optional in the Mango, can give similar squeeking sounds. The rubber dust caps on the bearings are the culprit. Because it's nice and dry inside the Mango, the rubber dries out and starts to squeek. So the first thing I do when I mount a DualDrive in the Mango is remove these rubber dust caps. There is no dirt coming towards the bearings, so the caps serve no purpose but create some drag and above all, very annoying squeeking noises.
With this in mind I took out the pedals one more time and removed the rubber dust caps on the bearings.
Peace at last!