Old timing belt risky - do they deteriorate?

Wig

If it looks fine, feels fine, I'd use it.

If it's still in the shop, use a different shop, but how do you know how long the new shop has had theirs for?

martyp

It's one of these gambles really, I may save £40 but then really regret it with loads of issues afterwards. The part I'm looking at getting is actually a genuine part for me car from the manufacturer so I'm thinking it would be more suitable than an OE or aftermarket part?

Wig

They will all be the same, near enough.

jase1

The question is why is the OP proposing to use a NOS part?

If it's because the car has been out of production for a long time, there may be no choice, and then I still would far rather have an unused, but older belt on the car than something that might be about to snap at any minute.

On the other hand, if the car is fairly recent and they just want to save some cash, I don't understand the logic. Tensioners will last pretty much indefinitely if unused, but belts won't, and given that they only cost between £7 and £20 depending on the model I don't see any good reason for saving the money to be honest.