A Wild idea for Favero Assioma pedals [MTB SPD Hack]

I think you’ll find that if you use something like this that you’re going to wish you didn’t. This kind of thing is just so top heavy it makes it nearly impossible to get the pedal in the right position. (Haven’t tried these but I’ve used similar ones before).

I sent Favero the following message:

I was wondering if there are any plans to release an SPD compatible version of the Assioma? It would be great if it were possible to switch the pedal body so that they could be used either on or off road. Do Favero have any plans to make this possible?

They responded saying:

With reference to your request, we are glad to confirm you that we are going to release a new version of Assioma suitable for Shimano SPD-SL. Official news will be released on our pages within few weeks.

We suggest you therefore to subscribe to our newsletter by clicking on this link ASSIOMA and bePRO Bike Power Meters | Favero Electronics and to stay tuned on our social media in order to get soon more detailed information about it. :wink:


Hey Carl, how are these working out for you now?
Just been reading the thread, and trying to decide which pedal bodies to go with, and thought I might try these.

Any negatives to report?

Got to say a huge thanks to everyone who has contributed to this thread, and given so much information on the conversions possible.
Gutted that M-Force are so hard to come by, with the 8’s being £200 now!
The CXR’s look like a good candidate, along with the Issi’s.
For now I have ordered the Bontrager Comp to see how they work out, after seeing a few mentions of them being done on here.

Was all set on the M-Force 8’s but am holding off, hoping there is a slightly cheaper option with the Bontragers.

Thanks again to everyone for their input. Here to learn.

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Just to be sure, you asked about SPD and they replied about SPD-SL. Did you reply and ask about plain SPD?


So I decided to start with the cheapest option first, and ordered some Bontrager MTB Comp SPD’s.
Arrived this morning, so got them swapped over.

Popped them in the NeoBike for a quick test, and all seems to track OK. Sadly I had just finished the morning run, so legs were too shot to do any consistent power efforts. But from the quick effort I did, they seem pretty darn spot on.

When put together they feel fine, no play on the axles, all buttoned up nicely and no movement, and they still spin freely.


Would love to see a breakdown of what bearings, bolts, washers and caps you used, in what order?

Have had some issues with my Xpedo CXR conversion so looking for an alternative.

@robertbb I followed these instructions with my CXRs and everything is flawless.

For mine, no bearings were carried over, just just what is in the Bontrager pedals, packed with a bit of extra grease. End bolt from either pedal fits fine, and the end cap is from the Bontragers too.

Not used them outside yet, planning to soon, but did a trainer session for an hour just now, very stable, track perfectly with the trainer as far as power changes go. Around 8-10 watts in it for the hour average. So not spot on, but nothing to lose sleep over. That said, I haven’t zeroed them since switching them to the trainer.

Will do that for the next test ride.

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I wrote back and asked:

Thank you for your detailed response but I’m interested to know whether Favero has any plans to release an SPD (not SPD-SL) compatible version of the Assioma?

They responded:

…we are working also on a new project for MTB use too, but it will be not introduced in the market in a short time. Unfortunately, I do not have any further detail to provide you and for this reason, I suggest you to subscribe to our newsletter.


Thanks for sharing!

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Hi how is it working with those pedals?

Everything good so far for me. No issues jet.

Wow, just bought a pair. What bearing cover/spacer did you use? I am measuring mine to need a 1.3mm or less spacer, so am just running without currently.

I only have a left 4iiii to compare with, but I did a ramp test and not sure if it’s good or not.
End of 2020:

It seems I skew towards right leg stronger near the end of the ramp.
But, looking at left side only, assiomas start to read 3% higher than the 4iiii at the end.

My last dual record had the similar thing though.

For anyone looking to hack different pedal bodies onto the Assiomas, GPLama stated that XPEDO is owned by Wellgo. (See his Keo cleat compatibility with power meter pedals video on YouTube).

Knowing that, you might find a Wellgo flat pedal that works with the Assiomas.

@GPLama this might make a good video for you to do if you can find Wellho flat pedals that work with the Assioma hack. That would be a first in the market solution for MTB riders that prefer flats or commuters that want every watt tracked.

The problem with the Assioma is the size of the battery/electronics pod. It’ll get in the way with a flat pedal if your foot is too far inwards. Their Look style road pedal works as the shoe is elevated above the cleat and clear of the pod. The SPD hack / shoe hack requirement isn’t ideal. More on this topic in… 5hrs…


The problem with the Assioma is the size of the battery/electronics pod. It’ll get in the way with a flat pedal if your foot is too far inwards. Their Look style road pedal works as the shoe is elevated above the cleat and clear of the pod. The SPD hack / shoe hack requirement isn’t ideal. More on this topic in… 5hrs…

Responding to GPLama and following up with my prior Wellgo M194 experience here.

I don’t recall clearance being too much of an issue on the M194s. However, what did become an issue is the drag on the pedals, and eventually one of the pedals developed a lot of lateral play. I called it quits after that. I picked up a set of Crank Brothers Mallet shoes and iSSi Trail III pedals with the hope that soft soles would make clipless riding in technical terrain close enough to flat pedal riding for my purposes. That was a disaster. Because the pedals sit so close to the pod, I had to shave off a chunk of the tread instep to clear the pod.

That was fine on tame riding, but when I got into technical trail where I had to use a lot more body English, it wasn’t nearly enough clearance anymore. The sole of the shoe stripped off a fair amount of plastic from the pod body in a matter of minutes. The pods look like hell now, but thankfully they still work and the charging ports are still functional. I’ll have to shave off a lot more tread before the next attempt with those.

The Mzyrh pedals mentioned by @wafflenator look like a good flat pedal alternative, but honestly it looks like shoe/pod clearance would be an issue there too, and I’m not going to take a Dremel tool to my FiveTens. I do still want a good flat pedal solution though. I use these on my eMTB and it’s good to be able to review my Strava data and see how much power I was actually putting in since the assist is definitely going to throw estimated power values off.

I’m assuming this is because of the Q-factor concern you mentioned in the Assioma SPD-SL compatible spindle video? FWIW and n=1 and all that, but I seem to fit your thought that maybe MTBers won’t mind it (I also don’t know if being female might have an impact on my feelings as well). I use mine on the trainer (on an old MTB) and on my normal MTB when I’m riding terrain where rock strikes are a lower concern, and I don’t notice a difference in terms of general comfort or wanting a different foot position, even over longer rides, between the Assioma hack pedals and my Shimano M520s, which I believe have a Q-factor of 55mm. I don’t know whether it matters, but I also didn’t have to do anything to my shoes to get them to clear the pod (I always assumed it was because I have smaller feet wearing 39s). I am pretty much exclusively (~95% of the time) a MTBer when I’m not indoors on the trainer. I’ve got decent hours on my hacked Assiomas at this point (~7 months) and haven’t had any discomfort issues with either of my two primary setups (trainer and outdoors), but maybe I’m just not particular about this (although I do have a history of various knee issues I dealt with in the past from when I used to run). My main MTB is fairly new, and I’ll be going to the fitter in a few weeks to get my fit fully dialed in on the new bike, so I’ll be sure to bring both sets of pedals and have this discussion during my fit since I do switch between the hacked Assiomas and the M520s on that bike depending on the terrain.

So @GPLama do we think the Duo-Shi is gonna make hack easier, i,e, they’ll slot it just as easy but with the seal?

Also reckon an Uno-Shi might make an appearance?

No change other than having to pry the glued-on oil cap off the DUO-Shi sensor (it’s the same spindle/sensor/everything). If anything they’d not be as suitable for the SPD pedal body hack as they say calibration is different.

UNO-Shi. Maybe. The dummy pedal on the right would have to have a massive 13mm spindle extension to match up with the left.

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