Used Bike Guide – Seat & Tyres

Filed under: Buyers Guide |


  • Look for: tears in the vinyl cover. New upholstery will cost around £100-150 from an auto/marine reupholstery place. (Check the yellow pages.) Seats with cracks and tears retain water and get your butt wet many days after the last rain. Highly annoying.
  • Seats (or tail sections) typically use a locking release (like the gas cap) to prevent vandals from messing with your bike’s electrical stuff. Make sure the release works with your key. If it doesn’t, it’ll probably cost around £80 + half an hour of labor to replace.
  • Check to make sure the seat is stable and latches on snugly.


  • Ask the owner how many years and miles the tyres have. The owner should know. (Bad sign if (s)he doesn’t!) The tyres should have at least 1/8″ of tread left, preferably more. Squared-off tyres, any signs of dry rot (really fine cracking — look really close!), bald tyres (no tread), knobby tires with worn down and rounded knobs… they all need to be changed. Tyres worth using aren’t cheap, but they’re your sole source of traction, your only connection to the road – do not cut corners!
  • Make sure you read the section above called has it been raced/abused?, as it has some pointers about how to identify vehicle abuse based on tyre wear.
  • If you get a chance to ride the bike, seek out well-maintained (smooth) roads so you’ll be able to tell if the tyres have flat-spots or aren’t balanced. (Both will cause perfectly rhythmic thumps or shaking that goes up and down as the speed goes up and down.)
  • Tyres should be changed at least every three years, though most serious riders would probably change them at least every other year. (That’s in an ideal world; tyres should be inspected regularly and replaced if they have damage that could cause handling problems or unexpected tire failures.)
  • How do you know how old the tyres are? All tires have an industry-standard dating code stamped on them. Look for digits stamped into the mold on the rubber sidewall of the tyre. The date code for tyres made prior to 2000 is: “WWY”, where WW is two digits denoting the week of the year, and Y is the last digit of the year. A tyre produced on May 30th (the 22nd week) of 1996 would be stamped 226. (A tyre produced on May 30th of 1986 would also have a code of 226, but will probably have a ton of dry rot.)
  • As of 2000, the date coding system has changed a bit. All tyres are still required to be stamped with a DOT number on at least one sidewall, but now there’s more data. Look for a code that starts with “DOT” and has up to 12 letters and numbers. The last four numbers are the date code in the format: “WWYY”, where the WW two digits denote the week of manufacture, and the YY denotes the last two digits of the year. So a date code of “DOT913ACX3C2200” would have been manufactured in the 22nd week of ’00. If the three/four digit stamp you found doesn’t make sense with this scheme, you’re not looking at the date code stamp. Keep in mind that both tyres will have this date marking (possibly/probably different), and that tyres should be replaced at least every third year, or whenever they have damage that threatens their integrity. (Punctures, cuts on the sidewall, excessive wear, dry rot, etc.) Frequent tyre inspection could very well save your life.

Dirt bike knobbies will tend to get worn on the forward edges of the knobs. Sharp knobs = good traction. (Nifty trick: If the leading edges of the knobs are worn (rounded off), but otherwise there’s nothing wrong with the tyres, you can unmount the tires and mount them backwards. Braking traction will suffer, but not too much. Note that this trick is only something that works on non-DOT off-road knobby tyres; street tyres should never be mounted backwards.)