I hadn't been sailing for months, if not a year, until recently. To my surprise the mast base tendon broke in two, just before I was about to launch. Luckily I had a spare, so it wasn't a drama.

So, I decided to replace the tendons on two mast bases. In doing so, I checked the other spares that I had. Of the 4 I tested by bending over, 3 of them tore in two or showed huge cracks that would have torn anyway.

So, what is the normal lifespan of these things? Is it the UV exposure, or just lifespan? In going through my spares I found a chinook boge joint and two-bolt deck plate. It looks like new. Do these fatigure the same way tendons do? (Just out of interest, one of the failures was also a Chinook tendon, so I don't think its a brand thing.)

Also, I decided to replace my NP MXT tendons with Chinook tendons. Other than the NP ones having the holes line up and the chinook ones being at 90 degrees, can anyone see a problem with these?