In reply to elsewhere:
Lots of useful input from others on original thread concluding on 22nd June with
It looks like the following should be compatible with existing square taper bottom bracket, current 11-34 cassette, rear mech capacity, frame geometry(?)...
Shimano Altus FC-MT101 chainset 36/22T
SHIMANO ALTUS TOP SWING Front Derailleur (Clamp Band Mount) 2x9-speed
https://bike.shimano.com/en-EU/product/component/shimano/FC-MT101-2.html
https://bike.shimano.com/en-EU/product/component/altus-m2000/FD-M2020-TS.ht...
Fitted the chainset today - all good.
Shortened chain
Front mech DID NOT FIT
The cable path and adjustment screws are behind the seat tube so suitable for bike (MTB, hybrid) with much more space between tyre and seat tube.
The old Sora road mech has cable path and adjustment screws more to drive side of seat tube and above chainrings rather than behind seat tube. The spec is for much bigger chainrings such as 48-32 and the cage around the chain is much longer. Moved Sora mech down 22mm ISH until cage almost fouls chainstay and 7mm ISH above chainring.
Lowest gear works ok, top gear some chain-front mech rubbing. Small small cross chaining some rubbing. Large large cross chaining ok.
Conclusion - if anybody tries this, give it a go with existing front mech before you buy a new front mech. Front mech compatibly is complicated and the conventional option of changing cassette and gear hanger extender if needed is a safer option.
Post edited at 17:10