Dry Weight Confusion
Am I missing something here or does the dry weight that is listed by the motorcycle companies include oil and radiator weight? Or is it the gas that makes it "wet"?
B. David Bland
Mr. Bland's letter, shown here, includes various calculations that attempt to reconcile the discrepancy between a manufacturer's dry weight and our printed listings of wet and dry weight. A manufacturer's claimed dry weight, which we print with a first-look or first-ride story, includes absolutely no fluids: fuel, coolant, engine oil, suspension fluid, battery acid-anything that could even remotely be considered a fluid is left out. For example, Suzuki's claimed dry weight for the '08 GSX-R600 is 359 pounds. When we test a bike, it goes on our scales with a full tank of fuel and all fluids topped up. We print that reading (441 pounds for the GSX-R) as wet weight. Dry weight as printed in a test is calculated by subtracting the weight of a full tank of fuel from wet weight, using six pounds/gallon as density. The GSX-R has a 4.5 gallon fuel tank, giving a dry weight of 414 pounds and a 55-pound difference to the claimed dry weight. Our numbers are indicative of what you'd encounter actually riding the bike, while the manufacturer's claims are only that.
Best Before Date
I had a question regarding tires and their lifespan. I have the original tires on my 2001 GSX-R1000, Bridgestone Battlax for both the front and rear. I bought the bike brand new way back in 2001 and have a WHOPPING total of ALMOST 1500 miles (no, not a typo I just don't get out much on my bike like I used too). You can go into all kinds of bike code, rules and regulations I am breaking by having such a lame amount of miles but here goes my question: I was under the impression that every 5 years, regardless of miles, you should replace your tires. I know there is some 'code' on the tire that lists the date it was produced so my tires may even be older than the March 2001 date that I got my bike.
Is there any truth to the 'decay' a tire will undergo once it is past the 'magic' five-year time frame? I store my bike (ok, basically all year round) in a heated garage and on a rear stand. The rear tire is almost never on the ground (insert jokes here) and that leaves my front to be the one holding the weight and force of the bike. Do I need to be concerned about replacing my tires (for when I do get it out on the street) or am I OK with the original tires?
You can find when your tires were manufactured by checking the DOT code molded into the sidewall. The last four digits indicate the week and year the tire was made (the 41st week of 2004 as shown in the picture here). No doubt your tires are coming up on eight years old now. Bridgestone's Motorcycle Product Manager Bob Graham points out that "the main issue in this case is that the warranty for weather cracking (for Bridgestone and other manufacturers) is limited to four years from the date of manufacture. For other warranty conditions, the limit is seven years."
Proper storage includes keeping the tires cool and away from direct sunlight and sources of ozone such as refrigerators or ozone generators/air cleaners. Even in proper storage, however, a tire's composition will degrade over time, compromising not only performance but also safety. Your tires may be okay for just cruising around, but if you are going to be riding your bike in the twisties and want to be as safe as possible, it would be best to swap them for a new set.
Got a question? Send a note to Sport Rider, Attention: The Geek, 6420 Wilshire Blvd., Los Angeles, CA 90048-5515, or e-mail firstname.lastname@example.org.