Back in December 2017 I fitted a 520 Z3 "Black Steel" chain made by JT, a company who are well regarded for their sprockets but not their chains. The Z3 looks to be an attempt to change that with JT boasting X rings and an average tensile strength of 4240kgf (41.6kN) which is very high for a 520 chain. The "Black Steel" version is the standard plain steel, you can also get "All Silver" which is nickel plated to combat corrosion and now "Gold & Silver" which is nickel inner plates and gold coloured outer plates. So, when first fitted it looked like any other standard chain:
As it was fitted in December it wasn't on for long before the bike stopped moving due to work shutting down for 2 weeks for Christmas. When I came back to it the half underneath the swingarm had corroded quite badly, leaving half the chain tight and half loose! Not a great start.
I carried on regardless, with the chain always a little on the loose side to accommodate the tighter half and after around 2000 miles it seemed to stop stretching and settled down, just like most chains. I was quite pleased with this as I'd paid £45 for the privilege of being JT's tester which is not far off decent D.I.D money. The chain also felt the full force of some unusual weather we received here in the UK, the so called "Beast From The East" which bought freezing temperatures and therefore huge amounts of salt on the roads for around a month. This did the chain no good at all but I wouldn't expect it to be wrecked, especially since the bike was used every day. At around 8000 miles it started to stretch a little more, until by 9500 it was stretching an unbelievable amount. At 9700 miles I tightened it again, and at 10,000 (exactly!) it was again hanging off the sprockets:
It had stretched so much I was starting to run out of adjuster.
JT also boast about the width of the side plates, as you can see they really are quite thick:
I don't doubt the chains are indeed very strong, but that apparently doesn't guarantee them a long life.
Upon splitting the chain the cause of demise became clear, no grease:
Given the way the plates had corroded it's little wonder the seals no longer worked well enough to hold the grease in, probably only helping hold water in there instead. As always, bend the chain sideways for a visual display of wear:
Not quite the full 180 degrees but not far off! For a chain that has done 10K I find this quite pathetic but it may be that the Kawasaki Z250SL destroys chains so I can't quite call it just yet.
So, thoughts - probably a really good chain in the coated versions, not so good in the basic Black Steel version because the steel JT have used is far too prone to rust and ruins the seals. Problem is, at the time of writing the coated versions are priced well into X-ring D.I.D territory so why bother?
