New bike chain claims to be faster, more durable

I really don't get it: what power are they claiming to be transferring on the side of the tooth that isn't engaging with a roller chain?

Also note that this is only for track bikes with a perfectly straight chainline (technically speaking it would also work for internal gear hubs wish are increasingly driven by belts in the upper price range). The shifting chain that is deployed diagonally more often than straight is an entirely different beast, in theory much worse in efficiency and durability. Pretty much all practical durability limits stem from compromises done for that diagonal capability for sitting. Which basically goes ruthlessly against all mechanical engineering rules, like the old adage about how bumblebees were supposedly unable to fly. Yet even they work quite well, given that challenging background they work just awesome and track chains already work better than that.

It's the chain not the internal hub. Rohloff can use either a chain or a belt drive. The belt drive is cheap, and works with other internal hubs (sealed planetary gear system), which are much cheaper (e.g. Shimano, others make them).

Reading through there is something very noticeably absent: any claims of increased efficiency.

If you spread pressure out offer wider areas, you don’t get less overall friction at least in the first order approximation of friction you find in first year physics.

What it looks like is an attempt to make something better that improves metrics which aren’t necessarily coupled to better overall performance.

That is mentioned in the article:

> All of that is working, too, with independent tests showing properly race-prepped drivetrains to be as much as 98% efficient.

> That elusive 2%

> As good as chain optimization has become, there comes a point where there’s no more optimizing left to do, and there are no other options but to rethink the system.

Though, not as in any modern drivetrain but high-end competition drivetrains. At least I imagine it would be with really expensive solutions like Ceramic Speed bearings everywhere.

Given a conventional chain can be up to 98% efficient then the maximum increase in efficiency is 1/.98 - 1 = 2.04%