Hi Mark,

Thanks for the reply. Never heard of powercranks but my knees are not happy at the moment so need to find an alternative to running every day.

The Trek models are as follows:

7300 WSD
7.3 FX WSD
Allant WSD
Valencia WSD

I've attached a word document to my original post comparing specs to save you looking it up on the Trek website.

I have a budget of maximum £500. Be most grateful for any advice, opinions or alternative suggestions.