Best E-bike drivetrain?

[PedalUma]

I am putting a seven speed 11-34 on a Specialized Roll mid-drive today. And an 8 on a Garry Fisher tomorrow. That way I can use a much stronger chain. It is for a commuter bike. It must be dependable. Also the parts are not only stronger but also much less expensive. The Supper Moto-X tires for it are on the way. Along with the Green Guard, it is getting tire liners and Stan's because the guy cannot afford to be late to work. I think it is a good looking bike. I set the speed limit to 45 and told it that it has 5 inch wheels. He will always have a spare quicklink in the bag. It rides like a Como. Zero zip ties.

 

[Surly]

Put a SRAM XD hub on it, shimano HG aren't fit for the job, most of the slippage issues are hub-cassette intefacing issues, an XD hub/cassette combo eradicates those problems.

At this point, I don't want to swap out the rear hub, although that is certainly a possibility if I don't get it sorted. Inteestingly, the spokes are not loosening excessively, although one might expect that they would.
Ward

It's the hub. You're caught in a circle jerk here, blathering on about chains....... it's shimano hg hubs. The 'loose' cogs ie not attached to the spider, slip under high torque, high load scenarios, it usually manifests in the mid to high gears, this is due to the height of the splines on the hub body, it doesn't lock the cassette in tight enough or as one fixed unit, plus the tolerances between the two are always off, so when you put lots of torque through ~4mm (the width of a single cog interfacing with the hub) it slips to the next spline/s.

SRAM XD don't have this problem as the whole cassette screws into the actual hub body thereby transfering the torque directly into the hub, there is no way for the cassette to slip.

I used to use box prime 9 drivetrains, both my bikes now run SRAM X01 mech and shifter with GX cassettes, difference is huge.

I ride proper emtb, very hard and it's extemely demanding on my bikes, i've been through all the slippage kerfuffle, most of the oldies on here don't hammer their bikes and are speaking from others anecdotes.

 

[kmccune]

I am putting a seven speed 11-34 on a Specialized Roll mid-drive today. And an 8 on a Garry Fisher tomorrow. That way I can use a much stronger chain. It is for a commuter bike. It must be dependable. Also the parts are not only stronger but also much less expensive. The Supper Moto-X tires for it are on the way. Along with the Green Guard, it is getting tire liners and Stan's because the guy cannot afford to be late to work. I think it is a good looking bike. I set the speed limit to 45 and told it that it has 5 inch wheels. He will always have a spare quicklink in the bag. It rides like a Como. Zero zip ties.
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I am still watching you and learning-KUTGW! And have come to love the water bottle battery.

 

[smorgasbord]

A Chain Wear test from Dec 2019: https://www.cyclingtips.com/2019/12/the-best-bicycle-chain-durability-and-efficiency-tested/

For 11-speed chains:

Wippermann Connex SX, Wippermann Connex SB, SRAM XX1 Hard Chrome and YBN E-bike as being the 11-speed kings of durability in terms of resistance to elongation wear (take note, the elongation wear qualifier is important, which I’ll soon cover). Coming in just behind, and reaching the .5% wear mark at near 3,000 km were the Shimano Dura-Ace (HG-901), YBN SLA Gold, Campagnolo Chorus, Campagnolo Record, and YBN Anti Corrosion.

For 12-speed chains:

Shimano’s new XTR 12-speed chain proved to be outstanding in this regard and aligns perfectly with what Shimano claims as far as improved durability. However, and as Kerin points out, the new chains feature a totally new plate shaping that’s designed to improve shift performance, but in turn, makes it a poor fit for other drivetrains.

...the results of SRAM’s high-end Eagle chains are simply mind-blowing. The top-tier X01 and XX1 Eagle chains both beat Kerin’s 5,000 km test and only recorded 70% of the allowed elongation wear at the time of doing so. Extrapolated out, these chains would likely have hit 7,000 km with the terrible control chain lube. They’re so durable, in fact, that they had started to wear through the cogs from pure abrasion before measuring as worn. Keep in mind that the control lubricant was intentionally abrasive, and so you can expect great life from your SRAM Eagle drivetrain if you keep it clean.

“SRAM claim the world’s longest-lasting chain with their XX1, and they are not kidding,” Kerin said. “Both the X01 and XX1 chains were so far ahead of any other chain from a pure elongation wear measure that I had to re-run the tests. The results were basically identical. Their longevity is phenomenal.”

Interestingly, they also tested 8, 9, and 10 speed chains and found that the 11 and 12 speed chains were MORE durable!

It seems that with each gear added, durability has improved. And at least for Shimano chains, 10-speed saw a significant jump in durability from 9- and 8-speed, and Shimano’s latest 12-speed XTR mountain bike chain rules the roost as Shimano’s most durable offering.

The article goes on to rate chains in cost/km and then in terms of efficiency, and they suggest training on most durable, then racing on the most efficient. Of course, this wasn't eBike testing.

 

[TrevorB]

I saw another test that 12spd had better endurance than 11spd. With both shimano 11 and 12spd cassettes the smaller cogs can be replaced individual which is great for ebikes that spend most of their time do >25kmhr. (15mph).
I typically get 3000-3500kmh from 11spd HG901 chains in commuter. KMC E11 lot less but that was on eMTB so wasn't unexpected.

While everybody talks about chain and cassette wear need to also think about chainring and idlers on derailleur.
With bosch CX gen2 small chainring has to be changed with chain, found this out hard way. On new Gen 3 with 40t I change it every 2nd chain along with cassette after running drivetrain into ground. On cost basis Gen 2 was cheaper as I could buy small chainring online for 5th price of 40t gen3.