Tyre Date Code

[Vince]

I planned on doing this for a while but a comment on Sunday's ride made me look at my tyre date code. Pre-2000 tyres have 3 digits, the first 2 are the week and the third is the year, and post-2000 has 4. These are after the DOT on the tyre. So my Michigan T66 tyres are front DOT HBVB 870T and DOT HBNN 978T
So my front tyre is from 1970 on a 1987 bike. My bet is it's probably a 1987 front tyre and a 1997 rear, even that's timed out to the max. I must have missed something here.

 

[helicopterjim]

I'm thinking there is more to the code than what you have posted. The 870T and 987T I believe have to do with manufacturer's data such as where made and so on.

The date code should be 3 stand alone digits.

Jim

 

[martymoose]

No dates pre 2000, 4 digit code after 2000. First 2 week, then the year

 

[martymoose]

Guessing I'll be seeing you for tyres huh?

 

[Vince]

Probably, there is a slow leak in the front for sure.

 

[sfcpiet]

Manufacture dates were mandatory in EU before 2000, stamping was 3 digits. First 2 for week, last for year. It was apparently assumed nobody would keep tyres for longer than 10 years, so there's an element of guessing with pre-2000 stuff. "870" does not make sense, there must be another stamping, without "T".

piet

 

[Vince]

I had 2 looks and that's all I could find., the T66 have been superseded a while ago and got far from glowing reviews. New tyre time for me.

 

[T.C]

Would change out the chain to Vince, just ask Pete with the Anniversary about trusting old chains.
Should be standard practice, new bike equals new tyres and chain.
Amongst other things of coarse

 

[Vince]

I hear the countershaft sprockets are tricky on these models.

 

[Andy J]

I hear the countershaft sprockets are tricky on these models.

They are the same as some other bike, I forget which one at the moment, so shouldn’t be too much of an issue.