Why is it rare for an e-bike to have more than one chain-ring?

[Sierratim]

Just out of interest, is there anyone who has sampled a modern 1x 9-12 speed drivechain and then decided to return to 2 or 3 x ?

Even my wifes 1x8 speed norco scene with a nexus hub has more than enough gear range to cope with any terrain she is likely to ride . I specifically bought this model because she never understood the front / back gear relationships , and also being able to change gears after coming to a stop in top gear seemed helpful.....

My kids accoustic mountain bikes are mostly 1x - they love it compared to the 3x childrens bikes they started out with. Admittedly some of that might be stepping up from vase level components to shifters that cost more than the previous bike was worth!

I hear ya about the component cost for the kids. When my sons raced MTBs in High School the prices of the parts they wanted caused nose bleeds! For my wife & I, not the 'boys'. I looked up one son's current favorite bike brand, Pivot. Nose bleeds all over again, and I'm not even paying for them now.

 

[ruffruff]

I hear ya about the component cost for the kids. When my sons raced MTBs in High School the prices of the parts they wanted caused nose bleeds! For my wife & I, not the 'boys'. I looked up one son's current favorite bike brand, Pivot. Nose bleeds all over again, and I'm not even paying for them now.

Tell me about it! I'm in the same boat with my kid!

 

[PDoz]

Confession time, 2 of my kids are riding my old bikes - a giant trance and a norco optic. Both bikes handed down as I bought something new and shinny. Sprog 3 has started dropping hints about my full e pro....

Sprog 1 earned her own bike after a few years slave labour / combined xmas and birthday presents and a little bit of being faster than me ....but I still get to call her slave any time I need a 15 year old to do something around the house....and every so often I'll take her scott genius out for a spin

 

[Sierratim]

Confession time, 2 of my kids are riding my old bikes - a giant trance and a norco optic. Both bikes handed down as I bought something new and shinny. Sprog 3 has started dropping hints about my full e pro....

Sprog 1 earned her own bike after a few years slave labour / combined xmas and birthday presents and a little bit of being faster than me ....but I still get to call her slave any time I need a 15 year old to do something around the house....and every so often I'll take her scott genius out for a spin

Yep, my 'boys' did lots of 'slave labor' to pay for their newest gotta have MTB parts. Now that they're in their 30's they still help 'dear ole dad' around the homestead, as it were...

 

[smorgasbord]

A powerful e-bike doesn't need more than five gears in most circumstances.

SRAM, for instance, makes an eBike specific drivetrain - the EX1. It's an 8-speed, 11-48 rear cassette.

Here's what they say:

The EX1 derailleur capitalizes on the robust build and precise shifting attributes of the X-HORIZON™ design, to create the world's first derailleur specifically made for E-MTBs. Engineered to handle high-torque, low-cadence shifting across the 11-48 tooth E-BLOCK™ cassette, the EX1 derailleur gives E-MTB riders clean, confident shifts, so they can spend more time enjoying the ride.

E-BLOCK™ shifting technology is a fundamental redevelopment of external drivetrain shifting. On the E-BLOCK™ cassette, the chain has a defined link position on each cog. Cog architecture has been engineered to work with both inner and outer links of the chain, which allows extremely refined shifting for both inboard and outboard shifts. The result is precise and robust shifting performance in any situation, even with full motor support.

The high torque loads of E-MTBs require tough components. The straighter chain line EX1 offers allows the use of a chain that is wider and more robust than those found on drivetrains not specifically engineered for E-MTBs. The EX1 chain has been engineered to run quiet across the gear range and transmit more power to the rear wheel.

But, it seems the 10-50 ratio of the 12-speed Eagle is just too appealing and many eBikes go for that, especially now that the GX cassette is about $200 and you can mix in the cheaper SX/NX Eagle stuff, too.

 

[Mike TowpathTraveler]

Here's my 2016 Haibike Full FatSix, Yamaha PW drive. Two front chain rings. As it's the only ebike I own and the only ebike I plan on riding into the long range future, I have to tell you, the two front chain rings make great sense on this bike. Unlike the newer FatSixes, which come with a single front chain ring driving a bigger rear cluster, this bike is alot like any 4 wheel drive truck with a 4 High and 4 Low range. I employ my bike the same way. Making a long but steep climb out of one of our local creek sheds, I'll shift to the small front chain ring and spin my way up. On our local roads, it's the big chain ring. The best of both worlds. No doubt though, with the popularity of the pie-crust pan sized rear gear clusters, the trend started by the Sram Eagle, it seems my two front chain rings have gone the way of the Dodo bird. But I'm really happy with my old school setup.

 

[pmcdonald]

I went for a ride last night with a friend. He was riding an analog road bike. To even the playing field I switched off my motor - not something I've done on my new bike (and 99% of the time why would I?). We hit some headwind and rode up a really big hill, about 1/5 at its worst. Perhaps with all the riding of late I'm conditioning my legs more but I was really pleasantly surprised to find I was able to keep up with absolutely no issue.

As Mike says above (startlingly clean chain, btw Mike - you'll have to give me some tips on chain maintenance) the two cogs up front act similar to a low and high range. I sat in the little cog on the flats and uphill, and used the bigger one on the downhill sections. Without the extra gears I would have had to lean on the motor or suck up the added pain.

I think perhaps for riders here dealing with higher legal speed limits, or for those with a bike for different occasions a single cog works just fine. Here in Australia we hit our 25 km/h limit so quickly those of us who want a little more legal pace really do rely on some nuance in gearing more than, say, our Class 3 friends in America.

Nevertheless, it's nice to know if the motor or battery dies, or if I want to ride more inclusively with unpowered friends it's a non-issue.

 

[Mike TowpathTraveler]

As Mike says above (startlingly clean chain, btw Mike - you'll have to give me some tips on chain maintenance) the two cogs up front act similar to a low and high range. I sat in the little cog on the flats and uphill, and used the bigger one on the downhill sections. Without the extra gears I would have had to lean on the motor or suck up the added pain.

Hi PMcDonald! Thanks! But for the sake of being honest, those pics were taken when the bike was just put into service in April, 2017, with 66 miles on the odometer. But to look at the chain right now, it pretty much is as clean as that photo from way back.

I think the folks who are changing out chains will find it interesting that I am still on that same chain, some 9800+ miles later, in 2020. Since I have no chain guage to check stretch, I cannot determine how much it has stretched beyond the original spec.

But I can say, there are no shifting issues, no slipping out of a cog. Cog teeth on the front and rear still appear to be good; if there is wear, I couldn't spot it.

I was always diligent about keeping my chain lubricated before most rides, a drop of my favorite lube for each chain link. My favorite chain lube is Dupont Chain Saver, which is a dry lube that does not allow dirt build up to accumulate on the chain.

Quite often before a ride and lubing up the chain, I'd wipe the chain down with a rag to remove any accumulated dust or dirt. A soap bike bath would also include a scrubbing of the chain and links followed by lubing it back up with Chain Saver.

And maybe just as important to extract that kind of life (this chain is the stock Shimano; I forgot the part number), my riding style includes pausing my pedals before I shift; never try to force a shift that causes that loud KLUNK! sound as the derailleur slams it home onto the next cog. And easy spinning up any grade, not stressing the drive line.

You're spot on about using the small front chain ring; the dual front rings almost makes the bike feel like a normal analog bike, albeit a very heavy one.

 

[alloo]

All Yamaha ebikes have multiple chain rings. Yamaha builds a mid drive ebike. Yamaha has been building ebikes since the late 1980s. www.yamahabicycles.com

 

[Saratoga Dave]

Most maybe, but not all. The excellent Wabash gravel bike is a 1X setup. I think it’s the only one, but they make a lot of them!

 

[FlatSix911]

Here is another nice example of an E-Bike that has a dual chain ring... the BH Rebel Gravel-X with a Yamaha PW motor.

Easy Motion Rebel Gravel-X PW Review | ElectricBikeReview.com

Price: $3399.00 | Model Year: 2018 | A lightweight electric gravel grinder with drop bars, aero wheelset, mechanical disc brakes (using Shimano ICE Tech rotors and heat sinks), and a 22-speed Shimano 105 drivetrain

electricbikereview.com

 

[QAJAQR]

Thanks to all who contributed to this thread. I've learned a lot. As a serious analog road rider, I've been all about steady cadence -- and plan to be that way as I start using an ebike for the local travels I used to do by car in exurban New England. I can see why most ebike riders are using a single chain-ring, and why I might want to have two rings to continue the habits built over some 40 years.
Thanks for taking so much time to construct suh good explanations.

 

[Captain Slow]

I have two ebikes a Juiced CCS commuter and a Specialized Creo which is an electric road bike. Both are single chain ring.

The Juiced is a powerful 650 watt hub motor and has 9 speeds and I don't need any more gears on it. A single ring is more than fine, and if the cassette was only 6 or 7 speeds I would think it would still be fine.

The Creo has an 11 speed cassette, but only a 240 watt mid-drive and most of the time I'm riding in pretty low assist levels. I ride it much like I ride my carbon road bike. On this bike I really would like a double chain ring set up. I find the cassette in order to have decent range has bigger gaps than I would like. It's an 11-42. I'd rather have double chain rings and then an 11-28 or 11-30 cassette.

When I use the Juiced in Eco my estimate is that I use roughly 5-8 wh/km, and if I ever use greater assist then it's more like 10 - 20 wh/km travelled. On the Creo I typically use about 2.2 wh/km and the other day when I used smart control where the trigger for the motor was my HR I only used 0.6 wh/km.

If you have a powerful motor then a single ring is fine, if you have a lower power motor and use your bike more like a conventional bike then a double is desirable. At least that's my experience.

 

[markybolton]

Yamaha offered some double front chain rings on their bikes, so you'll see some haibikes as well with them.
Not really necessary for a ebike.

I did a hub conversion on a Roll and it was a 21spd - going to 7 was just a non-issue with the drive motor. And it really cleaned up the crank area as well as the left bar - the throttle went there instead of the shifter.

It's way faster with the motor than it ever was pedaling it. LOL

I like your rack setup! Can you tell me the model and manufacturer? Did it come with the cargo net or did you put it on there?

 

[Browneye]

A standard alloy cargo rack from Blacburn or similar - it's been too long, and now the bike is sold.
Netting is a standard cargo elastic hook net for bikes or motorcycles.

 

[creativepart]

I converted my Specialized Crosstrail Sport with a Dillenger Off-Road kit a few weeks ago. The Crosstrail has a 9-speed freewheel (11-32t) and 2-ring chainring (44/32T) up front. After a couple hundred miles using only the large chainring I decided to try the small ring on yesterday's ride. After 7 miles I went back to the large ring and started looking at what it would take to simplify the front end.

I've been told that I should change out the chainring rather than just delete the small ring and front derailleur. I'm wondering what would be a good size for a new single drive front chainring? 46T, 48T or even 52T? What are others doing about this?

 

[MeDotOrg]

On my Bosch drive, I think of the assist level as an additional front chainring. When I'm pushing myself, the object is to take a hill with one less level of assist.

 

[Nycturne]

On my Bosch drive, I think of the assist level as an additional front chainring. When I'm pushing myself, the object is to take a hill with one less level of assist.

I ride similarly. Thankfully, now that I'm getting more active again, and actually bothered to set the tire pressure properly, I find myself in Tour or Eco most of the time, and Sport when I need speed or oomph. Turbo is really there for climbing hills or getting out an intersection in a hurry.

I use a about 75% of them on my rides. I enjoy travelling through them to find my ideal cadence depending on how much energy I have to throw at the ride. One of the bikes I test rode had 9 gears. I couldn't find my sweet spot at cruising speed - it feel somewhere between two gears.

I know this is an older post, but this also resonated with me. With the Nuvinci you kinda have the opposite problem. I find it easy to find a sweet spot, but since there's no real markings on the shifter, it's harder to repeatably shift and get the same result. So if I overshoot, I wind up having to re-adjust. I do kinda prefer this to the issue you describe though, even though I pay for it with efficiency.

 

[ChezCheese:)]

I never had more than a 10-speed in an acoustic before and it was plenty. My BH Atom Diamond Wave Pro has 8 gears in the back and 4 levels of assist at the midmotor, (plus no assist, if I want), which makes for 32 gearing combinations (40 if you count no assist). More than sufficient. I almost never use the first or eighth gears.

 

[john peck]

There´s a triple ring on my hub powered bike. I primarily use the middle ring. but I´m glad to have 3.
Having a selection allows me to find that cadence to gear sweet spot where Ï am using virtually no juice
to keep the 57 pd. bike moving with at least 6 pds. of miscellaneous. That´s a lot to just pedal, but once
it gets moving, it is possible. The very low range will absolutely climb anything, & the large ring is perfect
for cruising on the flat.
It has a 7 spd freewheel keeps the chain more inboard & is far easier to keep adjusted. I was constantly tweaking the cable on a 9 spd bike. It was prone to jumping multiple gears. A five degree temperature change was all that was needed for a cable adjust. The 9 was a real hassle to keep indexed.