Cheers for the infos guys..!

Wow- good to see that data sheets too, cheers..! Helps put things in perspective that and puts my mind at east a bit more.

Also, about my knee. I'm pretty tall, 6ft 6in, so when I've been putting my feet into the holders on the cycle machine pedals I've only been able to put JUST past my toes in- so it wasn't ideal. Big feet!

So, for the past two days, I've turned the pedals upside down and placed just above the middle of my feet on them- and almost ZERO issues with the knee..! I know foot placement has a big impact and this has really proven it to me- using the holders I was getting what I'd call "claw feet", were the front of my foot and toes would be clenched like a tense claw. This would in turn tense upwards up my lower leg and to the knee I'm assuming.
Upshot is I'm much more confident about the knee now and will continue as planned with training- but I've also got an appointment booked to see an orthopedic doctor tomorrow regarding the old knee injury anyway and give an assessment anyway.