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Assioma power meter 3-bolt to 2-bolt (SPD) cleat conversion using Xpedo CXR

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Assioma power meter 3-bolt to 2-bolt (SPD) cleat conversion using Xpedo CXR

Old 10-19-21, 02:53 PM
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chaadster
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Assioma power meter 3-bolt to 2-bolt (SPD) cleat conversion using Xpedo CXR

I just completed the conversion of my Favero Assioma powermeter pedals from their stock, 3-bolt pedal bodies to Xpedo CXR pedal bodies, and wanted to share a couple of insights on questions I had going into this.

First, while the Xpedo body swap job is a pretty well-known hack at this point, itís usually done (thanks to Shane Miller, aka GPLama) with the Mission Force 8 pedals. It was noted somewhere that the CXR should work just as easily and well as the MF8, but one has to dig a lot to learn as much. I did, anyway. So yes, CXR pedals work just fine.

I suppose the MF8 is most popular due to the lower weight, but I was more interested in the CXRís lower price. I only wanted the SPD cleat for seasonal use, during the winter, because thatís when a walkable shoe is valuable to me, being more sure-footed when itís slippery outside. CXRs are like $90 compared to $290. Conversion complete, the CXRs weigh in at 360g, whereas the MForce8 conversions weigh 330g.

The second thing I want to mention is that the conversion with either pedal body does not include a seal or cover on the inside bearing. Planning to use these as foul weather pedals, I was concerned about this, but I tripped across a single source discussing the use of a cover from the stock assembly, so I wanted to try this. Using that bit, a silver, stepped washer in the pic below, did mean the pedal would bind and not spin freely when the nut on the end of the axle was tightened. Shane Miller, in his vid, calls out that torque spec as 8-9Nm, but Iím not sure if thatís the original Assioma spec or the Xpedo MF8 spec, bit either way, Iím not sure itís relevant to the conversion. It may beó dunnoó but the MF8 conversion still has play in the pedal body when the nut is tightened, and relies on tightening the external dust cap over the axle to remove play.

What that tells me is that the torque spec probably isnít relevant to the power reading, because it couldnít be without a way to account for the lateral displacement, and because Miller notes power is accurate with the tightened dust cap. Since I couldnít tighten the nut fully with the inner dust cover in place, my solution was to use Loctite on the axle nut and set the preload enough to remove play. Both the Favero and Xpedo pedals has threadlocker on the external dust cover as well, so I redid that upon reassembly.

Iíll add that the stock assembly did not rely on the dust cover for preload, either.

Lots of folks have been running the basic MF8 conversion for many trouble-free miles over the past year, so maybe Iím out on a limb here, but weíll see. Iíll watch the power numbers for anomalies, and monitor the bodies for play. If I need to fix something or suspect issues, Iíll report back on that.

Other than that, the swap is superfast and easy. I donít think it would be a burden to do seasonally, but ultimately Iíd like to get the powermeter crank spider for the gravel bike and not have to worry about the pedals at all.

Hopefully this helps someone else trying to figure out how to get the most out of their powermeter money.




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Old 10-24-21, 10:09 AM
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Any other observations to share?

Thanks for posting this - I'm looking to do the exact same thing with a set of Duo pedals I already have. Question - Any comments about the conversion not mentioned above? Does the power readings seem accurate/consistent? Is there any binding on the pedal? Anything else?
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Old 10-24-21, 11:18 AM
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Originally Posted by mgringle View Post
Thanks for posting this - I'm looking to do the exact same thing with a set of Duo pedals I already have. Question - Any comments about the conversion not mentioned above? Does the power readings seem accurate/consistent? Is there any binding on the pedal? Anything else?
I would be surprised if the Duo-Shi pedals are compatible with this conversion, because the SPD-SL pedal body is different to the Look cleat Assioma pedal body, and so too the axle shape and bearing arrangement. I don’t know that for a fact, so just approach the project with failure a possible outcome. It doesn’t damage the pedals at all, so I don’t see any problem returning the CXRs provided you reassemble them properly.

To your questions, I’d refer you to Shane Miller’s (GPLama) videos on YouTube, where he walks through both the complete conversion and performance data analysis. As I noted earlier, he uses M-Force 8 pedals, but based on the experiences I’ve read on forums of others using CXR, there is no difference other than the cleat retention mech design and minor pedal body differences.

I’ve not really ridden the conversion yet due to surgery recovery, so I can’t say much of the conversion beyond what I’ve already posted. However, if by binding you mean between shoe and pedal, then yes, as noted by others, the inside lugs of MTB shoes tend to contact the Favero’s “brain bulge,” but a little slicing with a razor blade is a quick remedy.

Here you can see how I effected the remedy:


Shaved down inside lug on Mavic Crossmax Elite to fit Favero Assioma SPD conversion
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Old 11-09-21, 09:05 AM
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Following up on the results of my decision to run the bearing shield and use Loctite on the retaining nut, after a few rides now, it seems to be working fine. The pedals have not come loose.

Whether the bearing shield offers any meaningful protection is another matter, as there is no waterproofing gasket included. I’m hoping it provides some protection to the bearings and axle against corrosion and excessive wear, but who knows. I didn’t like the idea of the axle end and nut spinning against the dust cap, but also did not want the pedal body play, so this seems a good compromise.
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Old 11-22-21, 04:23 PM
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Would this conversion be reversible? I'm planning on doing a touring trip this summer and I don't think I want to be in road shoes to do it but I would like the power meter for the trip. I would want to convert mine back to road use after. I don't see why not, but since you've done it what do you think I'll run up against?
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Old 11-24-21, 01:58 PM
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Originally Posted by zacster View Post
Would this conversion be reversible? I'm planning on doing a touring trip this summer and I don't think I want to be in road shoes to do it but I would like the power meter for the trip. I would want to convert mine back to road use after. I don't see why not, but since you've done it what do you think I'll run up against?
Nothing. Itís totally reversible and redo-able. Iím planning to do it seasonally, as I have insulated, SPD shoes for winter, preferring the walking stability in slippery conditions.

The job takes like 7 minutes to swap bodies, thatís it. Thereís no destruction or modification of anything.
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