1978 CB550 F2

[Nurse Julie]

I see, makes sense

[Nurse Julie]

Does it say 3.60 H19 ? Is that an old tyre size as it seems a bit meaty

[Green1]

That does seem to say that if so looks over sized

[Nurse Julie]

Yes, that's what I thought. They should be 3.25 front. Hopefully get round to seeing it soon, if no one pushes the buy now button beforehand. Anyway, it's only a bike, plenty more out there to be bought. Thanks for your help Shrimp, sorry, Mick xx

[Green1]

Rear tyre is 4.10 18 so that looks over sized as well unless Honda did use those sizes that year. 

[Green1]

Just been told by my brother who is a tyre fitter by trade pre 2000 tyres often have a 3 digit code so 184 will be 18th week 1994
but now I'm wondering what the code would be for 1978 if they even have a code

[Nurse Julie]

Yes, I see what your saying. I'm not really worried that it's got a non standard size fitted. As long as they are black, round and stick to the tarmac, I'm a happy bunny.

[Green1]

Youve done it now I need to know if tyres from the 70's had a code?

[Nurse Julie]

  Don't loose any sleep over it. Let me know when you find out

[Green1]

To late my eyes sting like crazy but I need to know.

[Chris400F]

Does it say 3.60 H19 ? Is that an old tyre size as it seems a bit meaty

I have no idea what Julie and Mr Green are looking at!
Back in the late 70's when I were a lad people removed the original fit Jap crap rubber and replaced it with TT100's or Avon Roadrunners.
If I remember right then 3.60 H 19 would have replaced an original 3.00 x 19 and similarly a 4.10 H 18 would have replaced a 3.50 x 18.
Can't remember why the sizing was different, something to do with the profile I think.

Oh, found this about dating on older tyres (from a US site, hence the spelling of 'tires').
"Tires manufactured during the 1980s had a three-digit code for the date, with the first two digits indicating the week, and the last digit indicating the year (355 would mean the 35th week of 1985) and tires manufactured in the 1990s had a three-digit date code but with a little triangle (Δ) after the code".
Haven't seen anything about tyres from the 70's, not that you would want to be using them anyway!

[Nurse Julie]

I was looking at a bike on Fleabay Tom and the tyres looked a bit chunkier than they should  be. I didn't know what would have been on as standard. I have now  been to see the bike and they are indeed oversized.

[mike the bike]

Thanks for the explanation Mick, I thought they were 506 years old.

[Green1]

Thanks for the explanation Mick, I thought they were 506 years old.

Being in Wales yours probably are 

[mike the bike]

Meaning...what exactly?