I have a Sigma 1606L and really like it. You will have to order a rear wheel mount kit but they are pretty inexpensive. I have a Sigma on my recumbent and have recently ordered another rear wheel mount kit so that I can use this little computer on my DF. The Sigma 1606L can also be programed for two bikes and will track your mileage and time for each bike. You simply have to order a wheel 2 rear wheel mount kit to take advantage of this option.
Good luck and I hope this helps!