When Shimano launched its Dura-Ace 9000 groupset back in 2012, it introduced a new weight-saving technique, where the outward and inside faces of the cranks were bonded together, with a cavity between them. An advance on the previously hollow-forged design of Dura-Ace 7900, Shimano claimed its new Hollowtech design saved weight with no loss in rigidity.
A few years later, reports began to emerge of crankset delamination and failure, reaching their thousands before Shimano acknowledged there was a potential issue with the bonding process.
This led to the recall for inspection of around 2.8 million 11-speed Dura-Ace and Ultegra cranksets worldwide and Shimano agreeing an $11.5m penalty in the US for failing to report the problem promptly.
With the deadline to submit a claim approaching in August 2026, we look back over the timeline of Shimano’s costly product failure.
2012: Dura-Ace 9000 launched with new bonded crank arms
Shimano launched its first crankset with bonded arms as part of the Dura-Ace 9000 groupset. It was its first with four arms, in place of five, which were arranged asymmetrically on the spider rather than being evenly spaced.
The outgoing Dura-Ace 7900 groupset – launched in 2008 – also used a two-piece hollow design, but the parts were forged together, rather than bonded.
When we reviewed the groupset, we commented on the larger section to the alloy crank arms over the predecessor Dura-Ace 7900 groupset and on the visible bond line between the two faces.
It was followed in 2013 by Ultegra 6800, which, in Shimano fashion, replicated at a lower price and slightly increased weight much of the functionality of the flagship groupset.
Mid-2010s onward: crank-arm failure reports emerged online
The first reports of failed Shimano cranks emerged online. Starting in late 2017, the @thanksshimano Instagram account began to fill up with shots of failed Shimano Ultegra and Dura-Ace cranks, spindles and more, with the most recent dating from March 2024.
2020: BikeRadar first reported on crankset failure
BikeRadar has been following the Shimano crankset story since April 2020, when we reported on a crankset failure in the team.
Riding to work in January of that year, Stuart Forrest experienced a complete failure of the crankset, with the outer part of the crankarm separating from the rest of the crank.
He’d covered around 15,000km on the groupset in six years and had noticed a couple of weeks earlier that the cranks had started to creak.
Responding to our report, Shimano’s spokesman pointed to the huge global user base of its cranksets and advised riders experiencing problems to consult a dealer.
2021: Shimano said there wasn't a design problem with its cranks
In late 2021, Road.cc reported on a crank failure experienced by one of its readers, which spurred other riders to report similar incidents.
Shimano told Road.cc at the time that its engineers hadn’t found a design problem with its cranks, although it was investigating to see if there was a specific cause.
21 September 2023: official recall announced in the US
In September 2023, 11 years after it had introduced the design, Shimano announced a US recall of its 11-speed Hollowtech cranks in the US, and a global inspection and replacement programme.
This affected a total of 760,000 cranksets in the US and 2.8 million globally, after 4,519 reported instances of cranksets separating.
Affecting the original Dura-Ace 9000 and Ultegra 6800 cranksets, as well as the more recent Dura-Ace R9100 with and without a power meter and Ultegra R8000, this was the first time Shimano had acknowledged a problem with its Hollowtech cranksets.
Shimano confirmed owners of cranksets showing signs of bonding problems and delamination would be provided with a free replacement.
22 September 2023: Shimano clarified recall programme
The next day, Shimano clarified which cranksets were affected by the recall, specifying that only certain model numbers, for cranksets made before 2019, and with a specific range of production codes, needed inspection by a dealer and potential replacement.
Shimano excluded from its warranty cranks modified by third parties, such as 4iiii and Stages power meters, but included them in its inspection process.
October 2023: class-action lawsuit filed in the US relating to crank failures
In October 2023, a class-action lawsuit was filed in the US against Shimano, Specialized and Trek, claiming the announced recall was inadequate.
Because it did not cover all Hollowtech cranksets, the suit claimed cyclists could be riding a dangerous bicycle for an extended period without being sure their cranks wouldn’t fail. It also sought redress for riders who had already disposed of a failed crankset.
In addition, it pointed out that mechanics could be liable if a crankset failed subsequent to an inspection and caused injury.
Trek and Specialized were included in the suit because they were accused of “knowingly and intentionally misrepresenting, omitting, concealing, and/or failing to disclose material facts regarding the quality, reliability, and safety of the cranksets".
October 2024: some bike shops claimed they were ‘banned’ from the programme over high failure rates
A year later, Road.cc reported some bike shops claimed they had been put on a 'banned list' for the crankset inspection programme, because they had failed too many cranks. Shimano’s UK distributor, Madison, said Shimano would no longer pay the £35 per inspection fee to shops on the list.
Meanwhile, some shops claimed they were returning a large proportion of cranks to Shimano because they were not in a position to definitively pass a crankset based only on visual inspection.
August 2025: class-action lawsuit neared conclusion
Roll forward another year and the US judge issued preliminary approval for the settlement of the 2023 US class-action lawsuit.
The settlement was granted final approval by the court in February 2026 and involved Shimano issuing a magnifying device and a manual for retailers, to assist them in inspection. Shimano also opened a website through which affected riders could submit reimbursement claims. It stated the impact on its future business was expected to be immaterial.
March 2026: Shimano agreed to pay an $11.5m penalty
The US Consumer Product Safety Commission announced an $11.5 million civil penalty settlement with Shimano, which it concluded had failed to report promptly to the commission the defect in its 11-speed cranks.
The settlement also required Shimano to ensure compliance with the Consumer Product Safety Act and submit annual reports on its compliance programme and internal controls.
August 2026: deadline to submit claim form for class-action lawsuit closes
14 years after it launched Dura-Ace 7000, Shimano is finally looking to draw a line under the saga, with a deadline of 4 August 2026 to submit a claim, with documented costs, if you purchased and installed a replacement crankset on your bike outwith the replacement programme.
