helicomatic needs sedis chain
The original sedis chain that was supplied with my helicomatic free wheel had bulges on the inner links which I believe make it the only chain compatible with the helicomatic. I have come to learn this the hardway, a new shimano chain just floated on the higher cogs when shifting. People say sram are the same thing now, but when I look at something like the sram pc 830 I dont see any "bulges" on the inner links and visually it possibly wouldnt perform any better than the shimano?
My old sedis was only just at the wear limits and still worked fine, possibly best to keep using it.
Any other suggestions would be great