Favero Assioma PRO MX power meter pedals review

The Assioma PRO MX is Favero’s first SPD power meter pedal.

Designed for use on gravel and mountain bikes, the Assioma PRO MX offers accurate, dual-sided power measurement in a high-performing pedal system.

Best of all, at $759 / €750, it undercuts its most significant competition on price, with few compromises in performance.

In use, the Assioma PRO MX pedals have shrugged off the cold, wet and mud of the UK winter easily, while the data has remained as consistent and reliable as that from Favero’s road-specific power meter pedals, the highly-rated Assioma Duo.

Is this the best SPD-compatible power meter pedal available? It’s certainly up there.

Favero Assioma PRO MX specification

Intended for use on off-road bikes, the Favero Assioma PRO MX pedals are a Shimano SPD-style clipless pedal system.

The pedals are compatible with Shimano SPD cleats, with a set of steel SH51 cleats included in the box (these weigh 51g per set, including mounting hardware).

The Assioma PRO MX pedals offer dual-sided entry and exit – meaning there’s no ‘right’ or ‘wrong’ way up for the pedal body – and the release tension can be adjusted using a 3mm Allen key.

The pedal body is all metal, with impressive durability – they’ve already shrugged off a few rock strikes without trouble – while stack height is low at 11.2mm. Q-factor is, at 54mm, no different from a standard SPD pedal. 

The Assioma PRO MX pedals also carry a maximum rider weight limit of 120kg, compared to 105kg with Garmin’s Rally XC200 pedals (£959.99 / $1,199.99 / €1,099.99).

This is despite them being, according to Favero, the “lightest MTB power meter pedal” available at a claimed 191.4g each. On my scales, my test set weighed just under a gram more per pedal, at 192g each.

In comparison, Garmin’s Rally XC200 pedals weigh 222g each, while SRM’s X-Power pedals (£1,308 / €1,427.74) weigh 194g each.

Of course, we’re only talking a few grams here or there, but there are plenty of weight weenies in the world of cross-country racing, so I’m sure the potential weight savings will get some hearts pounding.

In terms of power meter specs, the Assioma PRO MX pedals are claimed to be accurate to ＋/－ 1 per cent.

All the usual stats, such as power, cadence and left / right balance, are reported, as well as advanced metrics such as power phase, platform-centre offset, torque efficiency, pedal smoothness and rider position.

They offer ANT＋ and Bluetooth connectivity, and include automatic temperature compensation and calibration systems to improve data accuracy.

Battery life sits at a claimed 60 hours (up 10 hours from the Assioma Duo), via an internal rechargeable lithium-ion battery.

This is double the claimed battery life of SRM’s X-Power pedals (30 hours), but half that of Garmin’s Rally system (120 hours). Garmin’s Rally pedals use replaceable LR44 batteries, however.

The pedals are charged via a magnetic charger in a similar manner to the Assioma Duo, though the two charger heads are not cross-compatible.

Favero acknowledges non-replaceable, rechargeable Li-ion batteries degrade with use (as anyone with a smartphone will know).

However, it says “500 complete charge-discharge cycles”, which is claimed to represent 30,000 hours of use (500x 60 hours), will cause an Assioma PRO MX battery to lose only 20 per cent of its charge capacity.

While I’ve only had the Assioma PRO MX pedals for a few months, a set of Assioma Duo pedals – which use a similar rechargeable battery – I’ve had since mid-2020 are still going strong with no battery issues whatsoever.

Sealed spindles and cheap bodies

In contrast to Garmin’s Rally and SRM’s X-Power power meter pedals, all of the electronic components are sealed within the spindle of the Assioma PRO MX pedals. This is claimed to improve durability and weather resistance, and reduce the risk of data drop-outs due to poor battery contact.

The pedal body itself is simply that – a pedal body. Favero says this enables it to make replacement bodies significantly cheaper, at just €49 each or €98 a set, and easier to service.

In comparison, a set of replacement Garmin Rally XC200 pedal bodies costs £259.99 / €299.99 / $399.99

Servicing or replacing a Garmin Rally pedal body, for example, requires fussing with a number of tiny screws and battery compartment parts (which need to be removed to access the spindle).

It’s not overly difficult (I can do it despite not being a qualified bike mechanic), but doing the same on the Assioma PRO MX requires just a couple of Allen keys and a pedal spanner. In other words, it’s easier.

Perhaps most obviously, this also means Favero has been able to do away with the unsightly pods its Assioma Duo pedals have. While the pods on Favero’s road pedals don’t impact performance, it’s fair to say they look quite awkward.

In contrast, the Assioma PRO MX pedals look like a regular SPD pedal.

What about an Assioma PRO road pedal?

This updated design also raises the question of whether a second-generation, pod-less road power meter pedal is on its way from Favero.

Perhaps riders could even have one set of power meter spindles and swap the pedal bodies between road and off-road as desired, as you can with Garmin’s Rally system.

Favero refused to be drawn on this, however, and said simply its Assioma Duo pedals would continue as its road-specific offering for the foreseeable future.

Favero Assioma PRO MX installation and setup

The Assioma PRO MX pedals are installed using a 15mm spanner. As with all power meters, though, it’s recommended to use a torque wrench for this task for optimal data accuracy. In this case, one equipped with a crow-foot spanner bit, to a torque between 30 to 40Nm.

As with most power meter pedals, one of the key selling points is the ability to transfer it quickly and easily between bikes. In the case of the Assioma PRO MX, there are no issues here.

Transferring them between bikes is quick and painless, you just need to ensure you set the crank length correctly (either via your bike computer or Favero’s Assioma app) and perform a manual zero-offset calibration before you start riding on the new bike.

Prior to connecting the Assioma PRO MX pedals to your bike computer, they need to be activated via Favero’s Assioma iOS and Android support app.

Beyond activating the pedals, this app can be used to do firmware updates, perform manual zero-offset calibrations, set crank length (it’s critical to get this right for accurate power measurement) and access customer support.

Activating the pedals via the app also activates the rider’s warranty, which sits at two years.

Favero Assioma PRO MX performance

On the bike, Favero’s Assioma PRO MX pedals haven’t put a foot wrong. First and foremost, the SPD pedal body is excellent.

While my experience with the wide world of mountain bike pedals is admittedly limited, there’s nothing to separate these from a set of trusty Shimano Deore XT M8100 pedals.

Cleat engagement is snappy and secure, while the tension is easily adjustable to suit your preferences.

The low, 11.2mm stack height and standard, 54mm Q-factor also mean there are no obvious compromises in terms of bike fit, as can sometimes be an issue with power meters (the Limits BIA and Favero’s own SPD-SL-compatible Assioma Duo Shi are two notable examples).

As on Garmin’s Rally and Vector 3 pedals, the backside of the spindle protrudes from behind the crank arm by a couple of millimetres. If clearance between your chain and bike’s chainstays is tight (Favero recommends a minimum of 4mm clearance), you may need to add the included spacers to the axle to prevent it contacting either and getting damaged.

Despite their impressively low weight (192g per pedal), the all-metal construction feels very tough, too.

I’ve not experienced any issues with durability or reliability despite abusing them in wet, muddy and rock-strewn lanes.

I’ve struck the pedals on rocks at least a few times and have even fully submerged them in a few unexpectedly deep puddles. Everything has been shrugged off without fuss.

I didn’t experience any issues with mud clogging the pedals and preventing me from clipping in, either. This bodes well for riders taking part in cross-country or cyclocross events.

As with the Assioma Duos, battery life hasn’t been an issue. 60 hours is more than enough to see me through more than a month’s riding (even assuming I used them for every single ride).

If you do loads of hours on the bike, of course, you’ll need to charge them up more frequently. For the average rider, though, I don’t see any issues here.

Favero Assioma PRO MX data accuracy

Over the more than three years I’ve been using Favero’s Assioma Duo pedals, accuracy and consistency have been as good as it gets, and the same appears to be true of the Assioma PRO MX pedals.

Up against other benchmark power meters, such as a Stages Ultegra R8000 LR and my trusty Elite Direto XR smart trainer, I’ve not spotted any issues to be concerned with.

As always when testing a power meter, I stopped to do a manual zero-offset calibration around 10 to 15 minutes into each test ride, but I also left the auto-calibration function on and didn’t see any divergences or issues further into each ride.

All things considered, I’d have no problems trusting the Favero Assioma PRO MX for training and racing.

Whether all of the advanced metrics are useful or not likely depends on your expertise, but they’re certainly ‘nice to have’.

For me, they tend to make it easier to spot if there’s an obvious issue with my bike fit.

If my saddle is too high, for example, my pedalling balance and power phases tend to go off-kilter, leading me to favour my dominant leg more than usual.

Of course, if you’re always riding the same bike or bikes, then this isn’t likely to be an issue for you, but it nevertheless might help you spot an issue you otherwise wouldn’t know was there.

Favero Assioma PRO MX bottom line

Usually, there’s some kind of compromise to a power meter – there’s no perfect power meter, after all. The Assioma PRO MX power meter pedals get admirably close, though.

In fact, if you don’t mind using mountain bike or gravel cycling shoes on your road bike, this could be a power meter to work on almost every bike you own.

It ticks all of the right boxes, with excellent data, a robust build quality, good battery life, easy servicing and, best of all, a very competitive price.

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