One is an original (Si), the other is second gen (SiSl), you can tell the difference by the SiSl having more material machined off around the crank bolt end of the arm.
The person I bought the cranks from sent me (originally) an SiSl drive side with an Si non-drive side, he finally sent me a matching non-drive side which I fitted this morning.
One is an original (Si), the other is second gen (SiSl), you can tell the difference by the SiSl having more material machined off around the crank bolt end of the arm.
The person I bought the cranks from sent me (originally) an SiSl drive side with an Si non-drive side, he finally sent me a matching non-drive side which I fitted this morning.