The perfect step-thru donor bike for conversion?

[UpWrong]

Spent the BH weekend fitting the display, the cut-out brake levers, all the cables and tidying up the rats nest. The 1 to 4 modular cable linking the controller to the display (and brake levers) was a problem. It was sold as KT controller compatible but wouldn't plug into the controller lead. I had to take a stanley knife to the modular cable plug to get it to mate with the controller lead.

Next step is to switch it on and configure the controller. If it's dead or displays error codes, I shall scream

[UpWrong]

Switch on - no explosion, no error codes. Success! I had no problem configuring the controller. Went for a test ride and it behaved as it should. However it is very undergeared with its 38/13 top gear, and the Wuxing brake levers with the motor cutouts are yuk.

[UpWrong]

Hmm, finding the top gear is graunchy. I think it's a cross-chaining issue, Am running a 26/38/guard configuration on a triple and the 38 to 13 (smallest on the cassette) is not smooth. Bit surprising given how long the chain stays are, The 38T ring is an 8-speed Acera. Maybe the teeth are thick and restrict the chain angle? (I can't get big-big, the RD refuses to shift there.)

[UpWrong]

Since the bike is both undergeared and appears to be cross-chaining in top, the best option is to try a different crankset using a square-taper, long BB spindle. So have ordered a TD-2 triple from Spa for £30 and I already have 32/46/guard rings for it, a left side KT PAS and a long spindle for a 73mm BB.

[UpWrong]

Just to complete this tale, I fitted a 122.5mm BB and a Spa TD-2 compact double with 33/44 rings. I couldn't go bigger than 44T because the step-thru frame wouldn't allow the FD to be raised any higher. The frame wasn't designed to take a FD. The KT left side PAS fitted onto the square taper BB spindle, and all is good. No problems getting on and off the bike and the weight distribution is good.

Incidentally, the 250W motor is capable of producing more than 600W for short periods which means I can keep a decent speed uphill and not overheat the motor.

EDIT: Still possibly a bit undergeared,https://ritzelrechner.de/?GR=DERS&KB=33 ... &DV=teeth#