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

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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For those looking into Bontrager MTB Comp SPD, I can confirm the conversion detailed by @Michael_Snasdell works. HOWEVER, the quality of Bont has a serious problem with unclipping, where your cleats would somehow linger onto the tip of the pedals after unclipping. There is also the issue of squeaking noise after ~100km. Both issues were actually in the reviews, but at the time I decided to take the chance. I now have to revert the conversion sadly.

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The iSSi pedal bodies have remained a reasonable solution for me (so far). :crossed_fingers: that it continues to be.

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Couple weeks out from SBT GRVL. Always do big changes to your bike right before an A event… Smh…

Took the dive and moved my Xpedo CXR Pro onto a new pair of dual sided Favero Assiomas.


If you tighten the nut to 9 nm the pedal freezes in place and cannot spin. Had to gently tighten the nut, then use the end cap to hold in place. Seems to work fine at the moment. No wiggle. Spins well. But will this become a problem since the nut is not properly tightened?

Have you encountered this, @GPLama???

There’s a trick that you have to use for the CXRs: Don’t use the dust cap that sits right against the pods. Then you can tighten the nut down normal. There’s still an O-ring that is there and will keep the mud out.

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Read this. It has the details of what to do to make the CXR body fit well.

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Even following the instructions posted above, I had this issue on one of my pedals (but not the other) because as I tightened down, the pedal body started to cut into the plastic pod. Not sure where I went wrong, but check for Mark’s on your Assioma pod to see if that’s the culprit. If so just do as you have, use the dust cap with some loctite to keep it in place.