What twohats Said, the warranty is on the original frame at time of purchase, otherwise you could effectively have a lifetime warranty if each replacement frame broke at 4 yrs...
And I would say quite rightly too.
It's an odd thing this; if a company have such confidence in an item that they offer a 5 year warranty on it from the date of purchase, which is a major selling point for many people, then if this item breaks and you receive a brand new replacement, then surely this item comes with it's own warranty. Remember this is a new item, not a repair, on which you would just get the remainder of the warranty. If the item constantly breaks at 4 years then it is clear that it isn't fit for purpose. After all, if the manufacturer themselves are saying each new item should last 5 years and it doesn't they should be liable for replacement. Each frame is distinct from the next. If they choose to replace not repair then it should also come with it's own warranty. I think you would win that one at court.
Thinking about it, it may boil down to the question of what constitutes a reasonable lifetime of this frame. At civil court where this would be heard, the burden of proof is based on the balance of probabilities, so I reckon any solicitor worth his salt would argue that if the manufacturer states it should last 5 years from new, an they give you a new frame, you have every right to expect that frame to last 5 years.
