Following the recent recall of 280 million Shimano 11-speed road crank sets, a class action lawsuit has been filed in the United States against parts manufacturer Shimano as well as professional bicycle manufacturers and Trek.

The 72-page document claims that despite issuing a voluntary recall in 2023/9, Shimano was aware of the problem as early as at least in 2016.

It also provides various case studies of breakdowns and refers to media coverage of crankset breakdowns dating back to 2017.

Shimano announced a voluntary recall in collaboration with the U.S. Consumer Product Safety Commission (CPSC) on 9/21, soon followed by a global "Inspection and Replacement program".

This is related to the 2-speed Ultegra and Dura-Ace load Crank sets manufactured between 2012 and 2019 across the 11 model series. These were sold aftermarket as well as OEM equipment for a variety of bikes, including but not limited to those from specialty and Trek.

Potential failure of problems related to delamination and separation of the joining segments of the hollow forged aluminum crank arm.

According to the CPSC, Shimano was aware of 4,519 failures. It is unclear if this was a global figure, or if it only relates to jurisdiction in North America.

The total number of affected users was cited by the CPSC at 760,000. Shimano later confirmed to Cyclingnews that the global figure is 280 million.

The action for the owner is to take the affected crankset to the local Shimano Service center, where the mechanic checks for "signs of adhesive separation or delamination"

If signs are found, a free crankset will be issued by Shimano. If not, the rider "can continue to use the []crankset as usual".

The lawsuit alleges that Shimano is "deferring to a local bike store to make important engineering decisions" in order to save money.

This suggests that this is "important to rider safety", given that it relies solely on visual inspection, without the benefits of stress testing." (58.b)

It also claims that Shimano "does not provide a remedy for a defective crankset that has not yet begun to fail" and puts riders "in a terrible position of having to ride a dangerous bike for months or years.", We are waiting for Shimano to separate the crankset and potentially cause a crash before giving them a new one." (58.c)

Shimano claims to have made the aforementioned decision "for profit reasons."" (59.

In the second half of the document, attention was drawn to bicycle brands selling models with affected cranksets, claiming that the defendant "fraudulently concealed" the defect. It cites Speciality and Trek as defendants in the case, but other brands, including BMC, have been referenced in the case study.

It states that "purchasers of defective crankset or class bikes paid more than the crankset defect had been disclosed."

In addition, it claims that all defendants "have known the crankset flaw for years."" (70.

Outside the US, a British government report recently found that the crankset did not meet current safety regulations. A two-page document from the Office for Product Safety and Standards claimed that the crank set posed a "medium risk" of injury to the user.

Crucially, it concluded that "the affected products do not meet the requirements of the General Product Safety Regulation 2005".

When contacted by Cyclingnews, Shimano declined to comment.