how old is too old?

[Grimly]

Eight year old tires on a bike that has been ridden occasionally and has been kept in a garage away from direct sunlight generally will be in far better shape than three year old tires on a bike parked outside all the time.

UV rays and direct solar heat degrade the rubber much more quickly than the rubber naturally outgassing when stored in a dark, cooler space.

I'd agree with that. When I put mine back on the road, it was with the same tyres it got laid up with. They were ten years old but had almost unworn tread, so I wasn't inclined to junk them if they showed no signs of deterioration. They didn't, so I just rode on them until they wore out.
They'd been stored indoors in a fairly benign environment.

 

[JMHJ]

I bought my '83 model 850 from the original owner in 2005. It had 7,500 miles and the original Bridgestone tires were still on it. the PO had it in the garage under a cover. All the rubber, etc. on the bike looked like brand new. I rode the tread off of the rear tire, and almost off of the front; I think it might have had some mild cracks when I replaced it.

No problems whatsoever.

 

[60ratrod]

My garage stays about 45*-50* in the winter thanks to it being attached to the house and because my forced air heater, water heater, and back side of my chimney are also in the garage, so I'm not worried about moisture out there. I do have windows on the garage door and both exterior walls, so there may be some sun light shining on the tires at some point. The tires on the gs will be replaced since there is deterioration. I'll see about the kz's tires next spring though

 

[Steve]

... but "Sarge's" tires are kenda challenger series. the front's date is 3909 and the rear is 1803, but aren't showing signs of aging like cracking or glazing, and look like they haven't seen much sun. ...

If that was my bike, those tires would not be seeing ANY sun. :-k

Not because of their age, but because they are Kenda Challengers.

In my opinion, they are barely qualified to roll the bike around in the garage.

.

 

[Grimly]

If that was my bike, those tires would not be seeing ANY sun. :-k

Not because of their age, but because they are Kenda Challengers.

In my opinion, they are barely qualified to roll the bike around in the garage.

.

I don't know what the Challenger's like on the U.S. market, but in the U.K. I had an early Kenda on the rear. Once I scrubbed it in, it was quite good, decent grip in wet and dry.
Then I hit standing water... the kind of standing water, just an inch or so that shouldn't have been a problem at all, and I was only doing ~40mph. The bike slid the rear around like it wanted to spit me off. The reason was - some total muppet at Kenda had made the tread design from a cross-wise series of zig-zags, so when it hit enough water, it couldn't clear out to the sides quickly enough and simply aquaplaned.
Stunning piece of design. I took it back for a refund and dumped it, the Kenda rep got it back from the dealer with appropriate words and I rode off with a Metz or Conti instead (don't recall which).
I reckon I wasn't the only one it happened to either, as shortly after that the tread pattern was changed and I had another Kenda later with no ill effects in the wet.

 

[bbjumper]

It's a fact. Rubber dries as it ages, and dry rubber doesn't stick the way new rubber does. Personally I'd feel uneasy on 5 year old tires, due to consensus I've drawn from people's opinion. Maybe you can get away with it, maybe tires age differently, depending on conditions... I've never tested it. I can tell you that 10+ year old skins are 'interesting' to ride on. Fortunately I wear tires out before age is an issue.

+1..... old tires even though they look great dry out and loose grip big time. And in the wet are no fun at all.

 

[60ratrod]

I take it kenda tires are a last ditch tire then. Good to know when I get new tires