I have a 6-year old Strida and the bottom bracket suddenly stopped functioning when I was riding: the cranks spin round without driving the belt. Is this something I can repair myself, if so how? If not, will I have to pay half the price of a new machine to get it repaired?
Assuming you have a Mk3 (with the freewheel in the front), it sounds like the pawls of the freewheel have got gummed up and so are no longer ‘clicking’ into place. I Had this, andn Although you could swop out for another (quality) 18 Tooth freewheel, you might be able to ‘un gum’ it by Laying the bike of its side and spraying something to thin the grease into the freewheel eg thin penetrating oil such as WD40, or even alchohol !
Once you have washed the sticky grease out the freewheel should be working - BUT you now must oil it with a thicker oil (something like auto engine oil) … you are then all set !
Here are some pictures showing how to dismantle the bottom bracket of a Strida 3 
Good pix - thnx for sharing 