Hi Bob,
Tested @ 5000 RPM riding, Neutral load , all fine.
Tested @ 5000 RPM Stationary, fine also, just a little tacho needle vibration. No surging.
Also did 40000 RPM @ £30MPH, as stated in my previous post, no surging here either, so i dont know where i got that from.
Regarding data cables, i know some guys in china managed to wire up a regular cable and got it to work.
For myself, i got a dedicated cable from Taobao via Taobaotrends.com agent (see spuds excellent tutorial
)
Though it is bit pricey
https://item.taobao.com/item.htm?id=39520023502
The cable cost $37.70 (£24)
It weighs 0.23Kg
I had mine shipped with some other stuff but if i have worked it out correctly,
i think you could get it mailed for about $6.00 using China or HK post with tracking.