Tire Question

[Crossrodes]

My '79 R65 has about 75,000 kilometers (50,000 miles) on it I think.  I have a new set of tires but....

The old tires have lots of tread on them and the sidewalls look good.

The rear tire is a Metzler ME77.  This bike was originally sold for the German market so the tires may be a different brand than bikes built for the North American market.

Looking at what I believe is the date code on this tire it shows 1378 (thirteenth week of 78).  Considering the build date of the bike it is entirely possible that this is an original tire but looking at the condition of the tire (it is less than half worn out) I wonder.  I am familiar with how long tires last on other bikes but my question is....Is it possible that this is the original tire?  Did Metzler use the same date codes on their tires as we do today back in '78?

Mike

[montmil]

I'd suggest you do some web-based research, including contacing a Metzler rep regarding the date code/s.  If the tire is a 1978 vintage, that skin oughta be as hard as a rock.  Stored indoors, the rubber may not have been subjected to the effects of ozone and weather but I personally would not trust a 1978-vintage tire at speed.

I just removed an ME77 from my R65 and it was rock hard.  Showed some hairline cracks on the sidewall.  Did not want to ride the bike further than the end of my street before fitting new rubber.  Done it.

[crazy_dan]

i've gotta feeling that that 1378 on the side of your tire is a warehouse or plant code rather than a date code, my me77 says 1318 on it and i just put it on last fall.  monte has another good point too, if that is the original tire, that thing would be hard as a rock and full of cracks.  if you've got new skins and don't know the history of the current ones, change 'em out man, be safe.
 [smiley=3stooges.gif]

[mikethebike]

My bike was sold to me with a "brand new" tyre on the front.  After riding it a little I noticed small cracks in the tread.  It was actually over 10 years old (date coded) and when I removed it there was a mass of cracks round the rim that went down to the cords.  Replace it if in doubt or at least remove it to check for deterioration.
Some info here:-
http://www.michelinman.com/tire-care/tire-saving-tips/maintenance-questions/

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11