Thanks for this
In the end I had ordered a draper one from
Draper 82143 1/4" Square Drive Socket, 9 mm Size https://smile.amazon.co.uk/dp/B078BL19B8/ref=cm_sw_r_cp_api_glt_fabc_X51RY0E5Z88FY739M2F0
Which fits well. Cheaper once delivery taken into account.
I had some Garmin XC and sold them because they literally made me cry… They were so bulky and heavy I couldnt handle it.
The accuracy and readings was fine, but by doing this I now have a set of power pedals that are lighter than XTR pedals with great engagement and are not a brick.
Thats my $.02
They are chunky monkeys for sure! 
What body did you end up using?
I ended up using the M-Force 8 in Chromoly spindle. This is the same one Shane used and honestly I think with my SPD cleats still on my shoes they feel better with engagement then my XTR pedals did. They seem more “crisp” and exact to me.
I used the “look” pedal bodies from the Assioma to make a nice set of road pedals for one of my other bikes.
Assioma DUO-Shi conversion. The additional width / Q Factor isn’t bothering me and I’m enjoying having Shimano SPD pedal bodies (M520). The add’l width improves shoe clearance from the pods.
Power comparison with P2M vs these in DCRainmaker’s tool = excellent alignment.
Super good job!
Shimano PD M520 and assioma duo Shi?
You had to change something, or you managed to fit them perfectly?
It’s a spot on match. I’d earlier spent a fair amount of time digging through the Shimano pedal exploded views, part numbers and what was sold as a replacement / cross-compatible.
If you read back up in the thread or search some of my other posts, you’ll get a quick overview of other options, etc.
Great!
Did you happen to weigh this combo?
The converted pedals are 417g.
Looking for a Shimano flat pedal body that will fit the Shimano spindles. The EH500 are flats one side and & SPD on the other. The add’l width of the Shi spindles would help keep their foot off the pod vs the original version and an Xpedo flat pedal body.
13mm Cycling Tips (see quote below)
From GPLlama: Pedal Q-Factor: 65mm
From DCRainmaker: Favero Assioma DUO-Shi Power Meter In-Depth Review (Shimano SPD-SL variant) | DC Rainmaker
Garmin Vector 3/Rally Series: 53mm (55mm with their stock spacer)
PowerTap P1/P2: 54mm
Favero Assioma: 54mm (55mm with their stock spacer)
Favero Assioma Shimano: 65mm
Shimano Ultegra (non-power): 53mm
SRM X Power: 54mm
" Combining the external power pod and Shimano’s own pedal bodies forced Favero to make one large concession – and the width of each pedal has grown considerably by 13 mm. The result is a pedal with a Q-factor of 64-65 mm (64 mm for 105 or lower, 65 mm for Ultegra), a far different figure from the 53 mm of Garmin’s Rally RS pedals."
What is the difference between a Shimano R540 and Shimano M540. The Favero Assimo is compatible with the R540. Surely there can’t be that much of a difference apart from the cages.
https://si.shimano.com/#/ is your resource for exploded views. There’s a post from 10/15 in this thread which lists what the p/n are for the Favero “Shimano” pedals. There may be more.
Duo-Shi spindles with PD-EH500 pedals for winter. They’ll be equipped with PD-A520s for gravel season. Data aligned nicely against a Power2Max…
Hi! Will the issi flash II work?
I don’t think so. The III work because they use bearings vs bushing/bearing combo. You can see the difference here: https://rideissi.com/parts/spindles
I have a Wahoo Kickr and 2x 4iiii left side crank PM’s. All are a bit off from each other and it bugs me! I known I can scale the 4iiii but I’m not sure which to believe is the most accurate. I expect the Kickr to be low with drivetrain losses, but the 4iiii are slightly off different amounts from the Kickr as best I can tell.
You’ve found the Duo Shi to line up well with a P2M, so do you think if I got a set I could “trust” them and scale the 4iiii from the Favero? The added benefit would be I’d love a bit wider Q factor on my road bike.
IDK about “trusting” X to scale Y. One of the converted sets was spot on, I ran out of fall season to check the other one on add’l rides. The initial ride was off a few %. I never use the initial ride as “the” test, need multiple after things are settled in. I have a third pedal body set up that I’ll also test but again, that will be spring before any of that will happen.
If you want 100% alignment and you use your kickr for indoor data, than perhaps you scale your two 4iiii to align with that.
That’s I appreciate the input! Problem with basing everything off the kickr is that reads lower, so it would drop my ftp a few watts 
