What do you think of "e-bike specific" drivetrains?

[kiltedcelt]

So I'm building this tandem recumbent tadpole trike that will have a BBSHD installed on it. The stoker seat will be removable so that a cargo deck can be installed so the trike will be able to do double duty as cargo hauler as well as tandem. Anyway, thinking about that REALLY LONG chain and mid-drive got me thinking about some of these component groups that are now stating in descriptions that they're "approved for e-bike use." The only thing I've found in the reading I've done to lend any credence to this "e-bike ready" business is that chains labeled as such might have stronger pins and side plates to resist snapping under torque. However, I ran my BBSHD on my other cargo bike with just a normal 9 speed chain and an internally geared 8 speed Alfine hub. Obviously, in my current case the chain isn't being moved by a derailleur so torque during shifting isn't so much of an issue. Also, geared hubs require you to stop pedaling when shifting, so the motor isn't sending power to the drivetrain anyway.

My tandem though, is going to have a regular derailleur drivetrain - specifically something like an 11-46 or 11-50 cassette in the back. Since most recumbents, especially something like a tandem use a LONG chain, I started pricing e-bike specific chains and immediately got sticker shock! Some of these chains (KMC) in a normal length are $55 per chain (9 speed), or as low as $18 for a regular 9 speed KMC chain. This trike is likely going to require as much as 3 separate chains joined together, so we're talking about a substantial investment in a part that gets thrown out when it wears out. The cheap-ass in me wants to just use a regular chain since I don't ever shift under load anyway, and I plan on installing a shift sensor motor cut-out anyway. Is there really any reason to pay extra for these e-bike-specific chains, or derailleurs or shifters if you're not building some kind of 3000w - 10000w off-road e-bike/motorcycle? Tandem plus cargo hauling tells me maybe I should use a somewhat more robust set of components, but for the most part it seems like the chain is the only thing that needs to be more heavy duty, not the derailleur and not the shifter. The only e-bike specific shifter I've seen is from Box Components and it seems to only be e-bike specific because it is designed to limit shifting to only one shift per click. If you're using a motor cut-off switch and you don't shift under load like a fool, why would you need anything other than just a stronger chain?

So, any thoughts on more durable components for this build, or maybe just use the basic stuff and see if holds up? I mean if I end up breaking the chain all the time or something then maybe I justify the cost of an upgraded chain?

 

[LeftieBiker]

If it were me, I'd rely on a smaller motorcycle chain long before I'd go by advertising copy for a bicycle chain. Something built to handle 15+ HP is likely to be able to handle a derailleur and much less power.

 

[Tommm]

What I can tell you is the kmc ebike chain, while not the longest lasting, is less likely to catastrophically fail because of its design, as it has filled, dome shaped pin ends compared to hollow ones for normal chains.

Peace of mind of a $28 chain is worth it over $18 for a regular one.
If you see it priced $50+, run.
I buy it from here, buying multiple at a time lowers the shipping cost per chain.
https://www.rosebikes.com/kmc-e9-e-ept-derailleur-chain-9-speed-e-bike-2666252

As I understand from chain tests, the longest lasting chains have some roller that actually rotates as it hugs the cog, but this quite expensive (genuine $50+) and I'll take the cheaper non ripping one any day.

 

[flat tire]

I thought all bike chain is roller chain. My 11 speed certainly is.

The ebike heavy duty chains are good not so much to prevent catastrophic failure, which is unlikely to begin with, but because they should stretch more slowly than non ebike chains. It would be good to see some data on that last point though.

 

[kiltedcelt]

Perhaps the KMC E9 E-EPT, is an older version of KMC's 9 speed e-bike chain? Universal Cycles' cheapest KMC 9 speed e-bike chain is designated X9e-Sport. That's the one that is selling at $40, and generally Universal has good prices - nothing heavily marked up. However, if I search for that E9 E-EPT I find it available everywhere, even Amazon for $31 (getting it from Rose Bikes with the exchange rate means it's about $29). I looked at the KMC website and frankly, I can find pretty much no difference between the two chains. The both have mushroomed rivets, 3x durability, ebike approved, etc. The only difference really is the EPT chain has an anti-corrosion treatment, so technically it's marginally a better value for the money have all the same strengths and improved rust-fighting protection to boot. Certainly $31 per chain (and free shipping from Amazon), is easier to stomach than $40 per chain. Hopefully the 3X durability (resistance to stretching), is worth the upcharge over the basic version of a 9 speed chain. The Rose Bikes prices is cheaper, but when you factor in shipping I think just buying the EPT from any US seller is going to be the better option especially if you can get free shipping. Mind you - there is *one* review on Amazon where a user says the spacing was too narrow to work with a Lekkie ring. I have a Lekkie ring currently, but will likely be replacing it with an adapter that allows me to run any chainring, mainly because I want to have the BBSHD chain ring match the chainring that's on the stoker crankset so I don't have anything screwy going on with gear ratios or whatever.

 

[markz]

Not only e-bike specific drivetrains, but there are also ebike specific tires and maybe even tubes. Speed rating and compounds are the key points there.

I'd love to have an inner tube that is double the thickness of a Kenda Thorn Proof tube, and more bicycle tires available in various treads with a thicker tread base (not including the knobs).

 

[Tommm]

Not only e-bike specific drivetrains, but there are also ebike specific tires and maybe even tubes. Speed rating and compounds are the key points there.

I'd love to have an inner tube that is double the thickness of a Kenda Thorn Proof tube, and more bicycle tires available in various treads with a thicker tread base (not including the knobs).

Better and lighter to go with thinner tube and use tubeless sealant in it, or even go tubeless.

 

[kiltedcelt]

Noting what Markz and Tommm have suggested about tires - I mostly haven't concerned myself with whether a tire was specifically "e-bike rated" mostly because I don't typically ride a continuous higher rates of speed. I think the regular higher rate of speed is where the e-bike rating comes in on some tires - specifically a lot of the stuff made by Schwalbe. My e-bike setups have always been more concerned about e-assist for hauling cargo and secondarily range - as in most miles per full battery charge. As such I seldom ride at sustained speeds much above 14-16 mph. I think as long as you're in that range or maybe topping out around 18 mph that you're probably fine without specifically trying to source e-bike rated tires. As to tubeless though, once I converted to tubeless on a bike (not e-assist), that I ran 29x3.0 tires on I was sold. Since then, every bike I've built I've incorporated tubeless. In some cases I've used tires and rims that were specifically NOT tubeless compatible. With a bit of ingenuity you can convert pretty much any rim/tire combo to tubeless. The benefits are less weight than with tubes alone, and secondly, with the sealant much less issue with punctures. I've occasionally had a puncture (pieces of glass), that have punctured a tire badly enough that I couldn't seal it and had to put a tube in. For my use case tubeless has worked just fine, but your mileage may vary depending on the types of e-bikes/speeds that you ride at.

 

[momus3]

It's not just about the increased speed. I tend to haul really heavy stuff w/ my eBike because I don't have to do the work, the motor does. Sometimes that rear basket has 20-40 lbs of something or other strapped into it or on it somehow. So spokes, tires, tubes etc are really getting strained in those times.

Here in Tucson, slime works great for tires. I used to put a heavy duty tube in the tires, along w/ a Tuffy liner AND slime. Now I just put slime in the standard tubes because that does the job. We don't have that glass-in-the-side-of-the-road problem because it seldom rains. It's all about thorns here.

 

[markz]

You can get tires with extra rubber on the tread.
You can get thorn-proof tubes
Yes, you can use tire liners or just use old tubes or even old tires put inside out (good ole Chalo's suggestion)
Use quality rims and quality spokes and nipples, lace it properly.
I bet you weight lets say 200 lbs, then your ebike weighs 50lbs then your cargo is 40lbs so close to 300 lbs which is nothing special by any means.
Some would argue for tubeless tires, but there are a few that say no and use tubes.
Smaller diameter wheel makes it stronger.
More spokes make a wheel stronger, for your front on a rear hub if you carry cargo on the front handlebars or basket.
I remember seeing an ebike chain for sale on Chain Reaction Cycle, for mid drives I guess, or maybe it had more links too.

 

[Balmorhea]

Better to get $10 chains and a chain checker, and replace them as they wear, than get a much more expensive chain that you'll be more hesitant to swap out.

If you think a $55 chain is pricey, how about a $429 eight speed cassette?
https://www.sram.com/en/sram/models/cs-xg-899-a1

For my part, I've never seen an expensive chain that was proportionally better or more durable than a cheap commodity chain.

I think e-bike-specific drivetrain parts are like every other "innovation" in the bike industry lately-- am attempt at higher profit margins. You can't really blame them for trying.