Favero Assioma DUO-Shi: Shimano compatibility for the cheapest power meter pedals on the market

The Italian outlier in the power meter pedal market is back with a cartridge system for Shimano users - but you'll need to be on board with wider Q-factor to adopt it. Here are our first impressions

favero shimano pedals
Favero's Assioma DUO-Shi adds power to your existing Shimano pedals
(Image credit: Future)

Favero has launched a Shimano-compatible system for its power meter pedals, ending months of speculation about the expected arrival from the extremely popular outlier. 

The Italian brand is the smallest of the power meter pedal manufacturers - going up against the likes of Garmin and Look/SRM. But arguably, in this David and Goliath match, these guys have a well-loaded slingshot to compete with the giants. 

Being lightweight, rechargeable and extremely reliable (in our testing experience), and much cheaper than competitors, Favero’s Assioma is a popular choice. And now, the DUO-Shi will cater for Shimano pedal platform users, where previously only those on Look Keo style cleats could join the party.

The new system is shipped as two cartridges, to be fitted to pre-owned pedals. And it looks good. But, not perfect - with the primary talking point among the Cycling Weekly tech team being the 65mm Q-Factor. That’s 11mm longer than the industry standard, at 54mm. 

Tech specs

Favero’s new DUO-Shi is available as a dual-sided model only, unlike the DUO/UNO in the standard range. 

The system is compatible with Shimano PD-R8000, PD-R7000, PD-6800, PD-R550 and PD-R540 pedal bodies. There have been riders hacking mountain bike pedals to accommodate Favero’s strain gauge spindles for some time, so it’s likely you may be able to fit them to other bodies, but it will void your warranty. The cartridges are not shipped with a pedal, you’ll need to BYOP to this power meter party.

The cartridge weighs 99g, a cartridge plus PD-R8000 pedal weighed 157g for us, which is exactly the weight Favero quotes. The adapter is made from aluminium, but the body which houses the nut used to tighten it and the pod is pastic (more on that later).

The Q-factor, as stated, is 65mm. A wider Q-factor will make for a wider stance width; the measurement defines how close together - or far apart - your feet are.

The Favero DUO-Shi's 65mm is significantly greater than the industry standard: 54mm. It wasn’t possible for Favero to wedge its pod against the pedal body, as it does with Look-style pedals, due to the nature of the Shimano spindle set-up. 

Whilst nearly all riders are on a Q-factor of around 54mm, this has been picked up as an issue by some bike fitters. Wahoo/Speedplay pedals have long been the only option offering a longer spindle. This will suit riders with a wider pelvis - particularly women; I’ve been keen to try a longer spindle for a long time. However, for those who are happy with the status quo of around 54mm, this could represent a bike fit issue.

favero assioma shi duo

(Image credit: Future)

Commenting on the Q-factor change, Favero said: “At the very beginning of the development of this project, this was seen with some concern, as the Q-factor generally adopted in the market is of around +54mm. At the same time, though, we knew that the body size (height, pelvis width, etc.) is a subjective factor contributing to determining which is the best q-factor for each one of us.

"On the whole, the majority of our beta testers have accepted this change, giving us a surprisingly, positive feedback at the end of the tests. That’s why we are excited to hear from our customers what they think about it!”

Skip to ‘ride impressions’ for my own thoughts. However, being a female rider, with a fairly wide pelvis, my experience might not be yours - it remains to be seen what other users will make of this change.

As per Favero’s existing Assioma power pedals, they use Instantaneous Angular Velocity-based (IAV) power calculation, as opposed to the average angular velocity used by most. The brand says that this better takes into account human pedalling dynamics, which are not uniform - resulting in improved accuracy. Accuracy is near impossible to measure accurately truly without a lab and some serious (read: expensive) equipment, but having used Favero pedals long term, I have always been impressed by their reliability. 

The rechargeable lithium battery lasts 50 hours, these transmit via Ant+ and Bluetooth and work between -10°C and +60°C.

The pricing isn’t entirely straightforward. In the UK, the Assioma DUO-Shi will cost €490 (£419) plus "possible custom clearance costs", and in the US, $589, plus "possible custom clearance costs". Regardless of the possible clearance costs, it's cheaper than the Garmin Rally (£969.99 for Look or Shimano or £1059 for SPD SL) and Look/SRM's collaboration (£1,280 at our last test). 

Fitting the cartridges to pedals