Citi Bike and Lyft recall

Citi Bike (New York City’s bike share system), also other bike share systems and the Lyft ride-share company, are recalling hundreds of electrically-assisted bicycles as of April 16, 2019, see this blog post. The brakes shown in the photo here are recognizable as Shimano Rollerbrakes, which rely on internal grease lubrication for normal performance. (Click to enlarge the image.)

An electric Citi Bike

These are drum brakes, but the brake shoe-brake drum interface is bathed in grease like that of a coaster brake. If the grease dries out or burns off, friction increases and the brake easily locks up. Details about Rollerbrakes: https://sheldonbrown.com/rollerbrakes.html. A rental bicycle left outdoors and untended could develop this problem and as a rental bicycle has multiple users, a user is not aware of the problem’s increasing over time.

The description as “touchy,” however, is nontechnical and may also describe brakes that would work for someone who knows how to use them. The problem is then in marketing bicycling as child’s play to, in the commonly used expression, people of all ages and abilities – as these are adult-size bicycles, to adults who learned everything they know about bicycling in kindergarten, by companies which turn a blind eye to that problem or are naively unaware of it.

In that case, the marketing plan is deficient. But what I expect to be done if that is the problem is to weaken the front brake, and then crashes will occur instead due to the inability to slow or stop in as short a distance. Photo source: https://cdn.vox-cdn.com/…/Citi_Bike_Electric_10.0.jpg

Here is a comment in the sheldonbrown.com article from mechanic Jeff Bertolet:

The life cycle of a brake goes something like this: add small amount of grease (pea size amount) in addition to factory grease when installing a new brake. After some months, the grease is washed away by rain. The brake is now dry and has poor or nonexistent modulation which locks the wheel with the slightest pressure on the lever. A normal consumer would regrease the brake immediately at this point, but our bikes [bike-share fleet bikes] can go a few weeks between being checked by staff. If it is being ridden dry for weeks, the drum and/or shoes are damaged beyond repair. Regreasing at this point can bring the brake modulation back to normal levels temporarily, but the brake will lose all stopping power within a few weeks or months depending on how much it is ridden.