Can I recommend a modification for all 3 wheelers and others without a spare. install Ride-on TPS in each wheel. I have been using it for over 10 years on my motorbikes and in my Aeros.
It is now available from a UK supplier (I used to bring it back from USA).
As well as prolonging tyre life and preventing punctures, it means you don't have to carry tyre foam and use up precious space.
http://www.ride-on-uk.com/cms.php?id_cms=9
