Cheapo exercise bikes?

Northwind Posts: 14,675
edited January 2010 in MTB buying advice
Just wondering if these are worth a shout, Tesco has a load for the princely sum of £35. I don't want a turbo trainer indoors and I would never bother to use one in the garage but I know from having a cheap rowing machine that if it's handy, I'll use it... But I've a suspicion it might just be a waste of time. What do you reckon?
Uncompromising extremist