bhdavis1978

Hi all,

I am looking to get my wife an e-bike for a friend. This person is somewhat overweight at over 250 lbs, though I don’t know exactly. I am debating recommending a geared rear hub with a torque sensor vs a mid drive. My concerns are about sufficient power to help the person confidently get up relatively short hills, usually around 5 to 6% incline, occasionally around 10% (but can be avoided with some careful route planning), although it will mostly be flat. I am thinking about recommending a fat tire bike version because they are not the most confident rider and I think it will be more stable for them.

What are the factors I should consider when making this decision? A mid drive bike I think will maybe ride better and have better torque, but will cost more if the motor needs replacing, although probably it may need less repair and replacement. A big advantage (maybe) of the rear hub is the throttle so if they get tired they can stop pedaling altogether, but the mid-drive is going to be better exercise I think, and probably with a high level of exercise it won’t be a problem. Especially because they can make it up some of the less steep hills (3.5%) currently on the lies gearing (26 front like 34 rear).

what do you folks think? What should I think about? What is your recommendation?

klevin

Hub drives seem to be the domain of cheaper bikes. Their motors appear to be less reliable, but easy to replace, although I haven't read much about anyone, except for homebuilts, needing to replace their motors. The ride quality reputedly is much better with mid motors, too. Throttles? Not my cup of tea, so others may need to comment. Personally, I find nothing difficult about peddling in order to get a boost, and I think it's a bit safer. Hill climbing? Usually better with a mid, since you get the advantage of torque multiplication with gearing.

Pop N Wood

Mid drives come with throttles.

If the person is new to cycling getting used to the gears is probably the bigger issue. In that sense hub drives seem a bit more new user friendly. Can't lug the motor by using too high of a gear.

A BF member named KREN had probably one of the most insightful posts about hub vs. mid drives for new users. Apparently he has helped many people get into ebikes. I would search for his post but I've had a few too many Sierra Nevada's

klevin

Except that you can't lug a hub motor any more than you can with a mid drive. Modern electric motors, with their modern controllers, are different beasts than the motors we grew up with. Locked stator high currents? Not any more. The controllers current limit the motor.

With modern indexed shifters, I wonder how many folks find shifting hard to learn? Again, not like it was 40 years ago!

Pop N Wood

You can still overheat ebikes and burn things up by using too much throttle in too high of a gear. Shorten the motor life at least. Lacking gears hub motors need to be designed to work that way so one would think they are more resistant to hard starts. But that is just speculation on my part.

it is not the shifter that is the issue, it is knowing when to use it that seems to cause new riders issues. They never seem to know what gear to be in and certainly don't have the experience to shift anticipating needed changes. ebikes can exacerbate the problem of being in the wrong gear.

klevin

Maybe you can burn up a cheap hub motor, but the decent ones have thermal protection. And with modern electric motors like you invariably find these days, The power going to the motor is independent of rotational speed. In fact, one of the attractions of these motors is high torque at startup.

Knowing when to shift? You mist hang out with different folks than I do. I've never known anyone who couldn't figure out when to shift. True, some folks forget to downshift when they stop, but they quickly learn, and with an ebike it's less of a problem anyway.

Chuckles1

My pedal assist wants to jump the bike up to 10mph as soon as I start pedalling. That can be dangerous, thrusting you out into an intersection when you were just getting your feet settled on pedals or just pedalling to get up to the intersection to stop.

A throttle allows you to start very slowly, and get your feet on pedals and get you into your lane before you start pedalling, much safer than pedalling from a dead stop if you have a PAS that works like mine.

At least that's how it works on my rear hub drive bafang kit. I run it with 5 levels of power/speed, so level 1 Is about 10mph. So you need to be careful when starting, especially if new to cycling.

klevin

What brand motor and controller do you have? Mid or hub drive? My pedal assist motor behaves nothing like what you describe.

Pop N Wood

Dude, you need to spend more time on line reading about the real world problems people have with these things. They burn up, even the good ones, strip out plastic gears, toast controllers, you name it. Especially when ridden wrong. The internet is full of first hand accounts.

klevin

I have no doubt folks do these things. I also have no doubt the internet is "full" of accounts. But these things, and folks, are outliers, or using cheap(er) hardware.

But, it's too easy to over-generalize from the outliers. Heck, if I believed the internet, I should never receive my mail or packages. Everyone knows the USPS is full of problems. There are tons of complaints online about late mail, missing packages and such. But, gosh, my mail still comes every day. My Amazon packages (in rural areas like mine, USPS does last mile for Amazon) arrive when they should.

Chuckles1

REAR hub drive, Bafang SWX02 500W, 48V geared motor. Don't know model of controller. It acts like cruise control, in that each power level setting seems to have a top speed, and the system accelerates pretty quickly up to that speed. So starting out from dead stop, or low speed maneuvering, is best done with throttle, which applies as little power as you want. Noticed the safety issue first time I approached an intersection and gave it one last pedal to get closer before stopping. Pedal assist kicked in; thank goodness brake cutoffs work. Not a problem once you're aware of it, but dangerous for newbie!

late

My wife and I have mid drives, no throttle.

Regardless of where the motor goes, I would want a pedelec..

klevin

Interesting. I wonder if any mid drives show the same thing? Yes, I can see the safety issue. Must have been scary the first time you noticed.

Yet another difference to keep in mind when shopping for a bike!

Kabuki12

My wife has a cheapie electric bike with a hub motor and throttle. I bought it used with a bad battery about 5 years ago and bought a battery on eBay for a couple hundred dollars. That bike still works great but she was ready for an upgrade . I bought her an Electra Townie Go at the Trek shop with the Shimano internal geared hub and Bosch mid drive , no throttle. She loves it and claims it is much easier to ride for long distances and stronger on the hills. It has hydraulic disc front and rear brakes and seems to be built very well, much better than her old one.

chas58

made any progress?
Mid drives are going to have more wear and tear, and be more expensive. And, they are a lot better on hills.
I've been using a single speed hub motor for 8 years - its pretty reliable. And it has redundancy - works fine if the battery dies, and works fine if I can't pedal (i broke the chain once, but had no problems getting home on my commute).

Wow, so much wrong with that. I can lug my car pretty easily. I can lug my ebike easier (hub or mid drive). I don't know how old you are ("motors we grew up with"???) but ebikes are, for all practical purposes, pretty new in the scheme of things. (Lead acid batteries anyone?). But yeah, in my case if I abuse things, its the controller that gives out, not the motor - I'll give you that.

Pop N Wood

LOL. My mid drive does. Where does that leave us?

On second thought maybe it is just a grammar issue. was responding to another post implying only hub drives had throttles, guess I should have same some mid drives come with throttles as well.

Pop N Wood

Don't know about your specific model but all of that is programable on many Bafang controllers. One of the true benefits of Bafang. For each assist level you can set the maximum power and top speed. You can also set the rate at which it gets up to that full power setting. I downloaded a configuration file from a bike blog, it is set up really nice. Motor starts out pretty slow then smoothly builds up to full power. I can really feel this "soft start" when I stop and restart pedaling.

If yours isn't programmable the solution to fast starts is to switch to a lower assist level before starting off. Motor won't come on as strong that way. I constantly adjust the assist level with speed anyway. Makes it work like a torque sensing unit. throttles for me are for fast starts or merging into traffic.

Chuckles1

I have a 500C display. The only options are for 3, 5, or 10 levels of assist. I've always used 5 levels, and considered setting to 10, but I dont like too much button pushing. I know going to 10 levels would make it start slower at level 1, but am happy with using throttle for smooth starts. One of these days I'll try setting to 10 levels to see if the more frequent button pushing is worth the finer gradations in power/speed.

Pop N Wood

With a programming cable you can set each assist level to be whatever you want it to be. You could make level 1 produce a higher power than level 10 if you wish.

If you don't like button pushing you might be better served with a torque sensing unit.

Chuckles1

Just don't want to be constantly pushing buttons and shifting gears. 5 power levels is a good compromise. First year with the ebike; not looking to upgrade to torque sensing unit at this time.

Does the programming cable program the display (mine's a 500C) or the controller? Does it come with a program? Can you download the program on an android tablet and use it to modify the power levels and get the "slow start" mentioned above?

Thanks for any insight.

Pop N Wood

On the Bafangs it reconfigures the controller. The display gets disconnected to hook up the programming device. The configuration tool are free, mine runs on a laptop. People post configuration files, I downloaded one called Karl's Special Sauce.

here is a blurb about programming with useful links

• Reprogramming the controller: The Bafang mid drive controllers are fully programmable with an easy configuration software for optimizing power output. See this link for the basics of programming. Alternately you can use this custom written programming software ### backup link ### See here for a good discussion on BBSxx program settings customization ### Further info: A BBSxx programming overview ### Electricbike-blog: # 1, #2, #3.