I'll come clean -- I'm a bear of little knowledge regarding eBikes. That said, I'm trying to convert a couple of old (i.e. dating from the 1990s) bikes using Cyclotricity kits. It hasn't been straightforward, so here are some of the 'gotchas' I've either encountered and/or might apply to your project:
- If you're considering a front hub conversion, ensure that you have 'inboard' drop-outs on the front fork. If you don't, the motor casing might foul the fork blade ends.
- Your bottom bracket doesn't look suitable for some pedal-assist sensor (PAS) rotors (e.g. Cyclotricity's) due to the lack of clearance between the crank and bottom bracket shell.
- The PAS sensor needs to be fixed to either the down or seat tube. Your seat tube might be an issue because the PAS fixings might foul the front mech clamp.
- With such a small frame, be careful that the battery will fit and can be removed for charging.
- If you're considering a rear hub conversion, check that you have the correct gear system (freewheel or cassette) as at least some need a particular system.
Although not strictly legal, you can get by with a throttle rather than PAS if needs be. However, AIUI, range might suffer. For rear wheel conversions, you can always buy a new rear gear cluster if the one you have doesn't suit your chosen conversion.
As I wrote, I'm a beginner myself -- but I hope this helps. Geoff