tires one man's opinion
9 yr old tires are NOT SAFE, no matter how good they look. There is a box on the sidewall that lists the week & month of manufacture. Never buy NEW tires more than 2 yrs old, (& thats a stretch!). I have a KENDA 675 Challenger on one of my bikes, & its a good tire at a bargain $. The 671 I don't know about. In the AMA mag. during the winter, A business that rents bikes swears by the Shinko 777 tires ( avail. in black or white), as a cost effective replacement. Depending on how much you ride & your financial situation, the Shinko will need to be replaced every 2-3 yrs. Not a high milage tire, but performance is good wet & dry during the life of the tread. Last year when I put tires on my '03 the 777's were my first choice at <$200, but the white walls were backordered. & the bikes' tires were wasted when I bought it. The Metzler 880's are short-lived high mileage, high dollar tires. You can put all the miles possible in two years, but after that they start to "chunk". (fall apart). The Michelin Commander 2 is a great tire for the Volusia, when you can get a good "combo price". Black only. That's the tire I'm currently running on my '03. MC Superstore's combo $ for the pair was $210 last year. Try smalltires.com for the Shinko 777's. Bikebandit.com offers a 10% additional discount for AMA members.
Hope this helps .