Another successful week the Major Taylor Project's Earn-a-Bike took place last week. This week's class was on chains and derailleurs.
I personally find the derailleur to be the most difficult part of bike maintenance. There seems to be an endless number of variables, limit screws (how do you tell the difference between high and low anyway?), cable tension, whether this is all taking place on the front or the rear, the condition of the chain, as well as more detailed aspects. I was duly impressed when the kids were able to get nine out of ten drivetrains running smoothly.
The tenth one came from the same unlucky bike as last time, and had a rear derailleur that needed to be completely replaced. That will be a project for next week along with hubs and other moving parts.