Anyone here know if the frames on the IO are the same as the frames on the IOID? The io is singlespeed i believe, and the IOID is alfine internal gear. Could I ,say, put an alfine hub on an IO, and convert IOID to single speed? Cheers.

No reason you can’t convert in either direction. The i0id has guides for the alfine cabling whereas the singlespeed frames only have guides for the brake hose. More or less the same otherwise – I’ve had both and converted both ways straightforwardly enough. Fun frames too – enjoy!

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I put an alfine on an iO many moons ago.
IIRC the only thing that needed consideration was cable routing.

I had two io frames and they were identical bar routing as mentioned