Originally Posted by rabbitt
well according to HP Velotechnik's and other companies, the tubes are to keep the chain clean as well.
As a tube proponent, I can say that I don't think they matter for that. ICE claims that the tubes keep you and the trike clean. I started with tubes for that reason before I read their criteria and it is the only one that seems to matter. One thing that may be of interest is that chains seem to stay cleaner on a trike than a DF because there is no leading front wheel to send dirt all over the chain.
Chip