Is 11-Speed Overkill on eMTBs?

[LimboJim]

I have a few eMTBs; two were specced with 11-speed drivetrains and two with 10-speeds. I've put a couple thousand fairly hard trail miles on them thus far, and have noticed a trend: 11-speed chains wear out faster! I suppose this is logical given that they have to be be thinnner than 10-speed chains, but given the heavy torque provided by mid-drives, why are so many higher-end eMTBs still equipped with 11-speed components?

I recently read Park Tool's "When to Replace a Worn Chain," which says "If you are using a chain designed for ten or fewer gears, replace your chain as it nears the 0.75 percent mark. If you are using an eleven or twelve speed chain, replace your chain once it has reached 0.5 percent wear. For two-sprocket or single speed bikes, replace your chain as it reaches the 1 percent wear mark." Using this guideline, I find myself replacing 11-sp chains every 200 miles!

Clearly we still need well-spread gears for steep climbs and fast flat runs on eMTBs, but SRAM's new 8-speed EX1 groupset covers an 11-48t range, eliminating some of the unnecessary (IMO) in-between gears provided by 11-speed cassettes. I predict that all the major drivetrain manufacturers will follow suit, hopefully sooner than later... When it comes time and my cassettes wear out, I plan to use this more sensible setup.

My 2014 Haibike FS RX might be the exception. Its 10-speed drivetrain only ranges from 11-36t, and I suspect the Bosch motor was tuned to work best within that ratio. Jumping to a 48t cog might wreak havoc - has anyone tried?

 

[itsaulgoodman]

I agree, they are. My mountain bike came with a 10 speed setup, and even that seems like too much. I had actually increased the size of the front chain ring because I was getting so annoyed having to shift through the gears so quickly.

I recall Court mentioning in his video that one of the drive train manufacturers came out with an ebike specific 8 speed drive chain, which makes sense. I think it was SRAM.

Yep SRAM EX1. Found it: http://ebike-mtb.com/en/sram-ex1-lowdown-first-ever-e-mtb-drivetrain/

 

[indianajo]

The 7 speed Shimano rear cluster, used on many bargain bikes and e-bikes, has left me thinking I was getting old and slow, then walking home. The inner race comes unscrewed, the cluster rubs on the shaft a while as balls drop out, then the last ball to drop makes it lock up: until you get off and push. The method of securing the inner race, a steel ferrule tightened against an outer nut, strikes me, as totally inadequate. Especially after a long walk home pushing the bike.
I've had the previously popular 6 speed shimano rear cluster, the axle shaft break in two. It had a 5/16" diameter threaded shaft, which has been corrected to 3/8" in the 7 speed.I weighed about 180 lb when I broke it, on the road, but was carrying groceries in a rear basket.
I don't know of any problems with an 8 speed SRAM. But the regulars on roadcyclereview.com won't hear of any other rear cluster but the shimano, sram, or campelli 11 speeds. Even though the chains last less than one summer even cranking one self.
By contrast, I rode a 5 speed shimano rear cog about 12 years, (15 speed mtn bike) and never wore out the chain. The 3rd speed cog lost the tips of it's teeth, instead, which caused skipping. Neither did I ever wear out a chain on the Sturmey Archer 3 speed I owned for 30 years. However three speeds were okay for flat Houston & Kansas, but not hilly Southern Indiana.
One advantage of eleven speeds, with 28 to 11 cogs to choose from, one doesn't radically need a shifting front sprocket, until the grades go over 10%. Which makes it compatible with mid-drive e-bikes, that delete the multiple front sprockets.
BTW I ride >2000 miles per year, and don't wear out 6-7 speed chains in 3 years. I've changed frames more often than that, due to stability problems , incompatibility of old frames with new components, and the broken axle mentioned above. 6-7 speed chains are thinner than 5 speed. Single speed chains IMHO never wear out: we used them in industrial baking for seasoning dispensers.

 

[TrevorB]

My bosch CX eMTB came with 15t chainring and 11spd 11-42t cassette, could climb anything. I've since changed it to 14t and 11-46t as I prefer have lower gearing. A 14t with 9spd 11-40t would be equivalent to original gearing but would lose XT clutch which is critical with CX to stop chain suck in mud. SLX or XT 10spd with 11-42t would be best combination as chains and cassettes are slightly cheaper while having good range.

 

[33red]

I have a few eMTBs; two were specced with 11-speed drivetrains and two with 10-speeds. I've put a couple thousand fairly hard trail miles on them thus far, and have noticed a trend: 11-speed chains wear out faster! I suppose this is logical given that they have to be be thinnner than 10-speed chains, but given the heavy torque provided by mid-drives, why are so many higher-end eMTBs still equipped with 11-speed components?

I recently read Park Tool's "When to Replace a Worn Chain," which says "If you are using a chain designed for ten or fewer gears, replace your chain as it nears the 0.75 percent mark. If you are using an eleven or twelve speed chain, replace your chain once it has reached 0.5 percent wear. For two-sprocket or single speed bikes, replace your chain as it reaches the 1 percent wear mark." Using this guideline, I find myself replacing 11-sp chains every 200 miles!

Clearly we still need well-spread gears for steep climbs and fast flat runs on eMTBs, but SRAM's new 8-speed EX1 groupset covers an 11-48t range, eliminating some of the unnecessary (IMO) in-between gears provided by 11-speed cassettes. I predict that all the major drivetrain manufacturers will follow suit, hopefully sooner than later... When it comes time and my cassettes wear out, I plan to use this more sensible setup.

My 2014 Haibike FS RX might be the exception. Its 10-speed drivetrain only ranges from 11-36t, and I suspect the Bosch motor was tuned to work best within that ratio. Jumping to a 48t cog might wreak havoc - has anyone tried?

I recently bought a new 2017 haibike 20 S with 11-36. I had it replaced by an 11-42. It makes sense to use an easy gear to avoid draining the battery but some people ride 2 or less hour per day and for them stretching the power over 3.5 hours is not an issue. I like the 20S with range and a smaller front to climb. One of my bikes is an 11S but it weights 20 pounds so it has different qualities like acceleration and handling. I would not bet many will adopt less than 10 speeds. Bikes are made to sell for profits and 8 speeds are not trendy. Retailers and manufacturers will not feel attracted. Look at the new shapes, they allmost hide the battery to look cool they go for emotional selling logic is not the top concern in my opinion.

 

[BBassett]

Overkill is owning so many bikes and not having what you want.

 

[Feliz]

SRAM make a nice eBike specific 8 speed which to me is about perfect, your right though they aren't trendy and they seem to be selling poorly. It's the EX-1

 

[DaveMatthews]

I'd be happy with 8 speed, because there'd be less stress on the drive train.
That being said, if the battery dies on an extended or unplanned ride, the 10 speed can be useful.

 

[BBassett]

I'd be happy with 8 speed, because there'd be less stress on the drive train.
That being said, if the battery dies on an extended or unplanned ride, the 10 speed can be useful.

Cut the chase and get a Rohloff.

 

[steve mercier]

If I have to replace a chain every 3-4000 km , what is the big deal?

 

[DaveMatthews]

If I have to replace a chain every 3-4000 km , what is the big deal?

Agreed... no biggie for me at all.

 

[Captain Slow]

My ebike has a 9 speed rear cassette and I'd gladly lose a gear to 8 speeds for even greater longevity.

Was not aware of the SRAM 8 speed specific ebike drivetrain but it's a great idea. The motor means fewer gears are fine.

Even on my road bike, which has a 10 speed rear cassette, I've never felt I wanted 11 or more speeds. Maybe if I raced, but I'm too old for that.

 

[Feliz]

My ebike has a 9 speed rear cassette and I'd gladly lose a gear to 8 speeds for even greater longevity.

Was not aware of the SRAM 8 speed specific ebike drivetrain but it's a great idea. The motor means fewer gears are fine.

Even on my road bike, which has a 10 speed rear cassette, I've never felt I wanted 11 or more speeds. Maybe if I raced, but I'm too old for that.

It's the SRAM ex1 groupset, specifically for EMTBs.

SRAM EX1 review

What's it like living with SRAM's e-bike specific 8-speed groupset?

www.bikeradar.com

 

[Feliz]

I just purchased an emtb with a Shimano 11 speed and it's scary how skinny the chain is. It's on a bike with a Yamaha mid drive so I'm not expecting any sort of longevity. I wanted a bike with the SRAM 8 speed but the deal fell through.

 

[Feliz]

Cut the chase and get a Rohloff.

This thread is about eMTBs and I wouldn't want a Rholoff on my mountain bike. I do have a Rholoff on my Watt Wagon and it works well.

 

[33red]

I just saw a 2020 9 speeds, 632 Wh 3999$Canadian https://www.bikes.com/fr/bikes/growler-powerplay/2020?tid=419

 

[LimboJim]

My ebike has a 9 speed rear cassette and I'd gladly lose a gear to 8 speeds for even greater longevity.

Was not aware of the SRAM 8 speed specific ebike drivetrain but it's a great idea. The motor means fewer gears are fine.

Even on my road bike, which has a 10 speed rear cassette, I've never felt I wanted 11 or more speeds. Maybe if I raced, but I'm too old for that.

My Commencal MetaPower has the EX1 set up, which actually uses a 10-speed chain. SRAM does offer an EX1 chain, but it's the same width as 10-speed.

Commencal sent me the bike with a PC-1091, which hit 0.5% wear after 250 miles or so (lots of steep climbs where I ride). I replaced it with an EX1 chain, which now has over 300 miles on the same trails and has yet show any stretch. So maybe the eMTB-specific chain is worthwhile - it lists for less than the 1091!

 

[Johnny]

If I have to replace a chain every 3-4000 km , what is the big deal?

Except my chains are not going for 4000km (~2480 miles) more like half of that. $50+ for a chain every 1000 miles is not nice given I am trying to keep the drivetrain clean, lubed etc.

I prefer an 8-9 speed with wider range over 10-11 speeds.

 

[steve mercier]

I currently have a KMC E11. It was more money but it is supposed to last 8000k. I have only 1200k on it so far. We shall see how long it lasts.

 

[E-Wheels]

I currently have a KMC E11. It was more money but it is supposed to last 8000k. I have only 1200k on it so far. We shall see how long it lasts.

>8,000km should be possible with a centre drive
The original chain supplied on my Shimano E8000 ebike was a KMC X10e
I did 10,843km before having to change