Mid drives vs Hub drives ???

[Barry S]

My hub bikes are accelerators only, no PAS...

My apologies for the dumb question, but I've always wondered about a hub motor with no PAS. Is there a way to control the amount of power assistance like a cruise control setting or is it either fully engaged or not engaged by way of a throttle?

 

[JRA]

My apologies for the dumb question, but I've always wondered about a hub motor with no PAS. Is there a way to control the amount of power assistance like a cruise control setting or is it either fully engaged or not engaged by way of a throttle?

I use a Grin Cycle Analyst display, that among many other features interfaces with the controller and has a "cruise control" mode in the setup menu. It can be set to activate a 1,2 or 3 seconds. It allows you to set it at whatever speed you want to be going or how many watts you want the motor to produce. I have mine set so that just by holding the throttle for one second it will activate. I started with a 3 second mode but ended up at 1 as it is a conscious move and requires the throttle to be held still which sometimes isn't easy to do on gravé. It is easily disrupted by either hitting the throttle or the regen button which I have at either hand.

I tend to use it mainly on long clear stretches and for climbing long hills. I find that if I set the cc at 350w, select my gear of need, and some active pedaling long steep hills go by pretty fast while not eating many ah's while doing it. I use the regen button more coming back down though.

The largest part of my equation for me is using a front hub motor. That way my drivetrain is totally isolated from anything to do with the motor and can run any gear system I want. Most importantly it allows me to ride with just the right amount of input and cadence at any given time and a gear above and below that I can shift to as one would normally without any adjustments to the motor output.

 

[JRA]

"New concept ... motorcycle with pedals and accelerator 750w but with driver's license and insurance and out of the bike lane and childrens 16 years old"

We've had those here for awhile actually, we call them Mopeds. They are regulated by the Federal Gov't's Department of Transportation. This means approved tire/rim, full lighting kit, horn, mirror and is issued a VIN #. They never gained much popularity at least not as much as the Whizzer company did after WWII. Ducati also made a version called the Cucciolo:

 

[e-boy]

From Bicycling Magazine review of the Mid-Drive Specialized Womens Turbo Vado 3.0

https://www.bicycling.com/bikes-gear/a19850892/specialized-womens-turbo-vado-3-0-e-bike-review/


"Acceleration is smooth and immediate—a key strength for e-bikes. Getting a quick jump from a full stop gives a rider more confidence when riding in traffic. When you’re shifting gears or putting more power into the pedals, there’s none of the surging that can afflict some e-bikes with a herky-jerky feel. The lack of lag and the smooth ramp-up in power boosts helped the bike fly up hills with a nearly effortless feel (not all e-bikes do this, by the way—on some, hills still feel like work). The bike handles intuitively, without feeling like a behemoth in fast or sharp turns, and feels stable on steeper descents."

I had a chance to test ride the men's 6.0 ; I concur .

 

[keithd]

I hope would hope for $3500+ you would get a smooth performing bike

 

[TForan]

I hope would hope for $3500+ you would get a smooth performing bike

I agree and that's exactly what I got with my Biktrix Ultra. Feels like a regular bike.

 

[TrevorB]

For touring and eMTB factory middrives are only way to go. Tour needs the extra range that only middrives can deliver. With eMTB is power delivery and most importantly for FS low unsprung mass.

Cruising and commuting then there not lot in it, comes down to personnel preference. Middrives can be lot lower maintenance commuters especially with IGH enclosed chain cover or belt drive. Most of hub commuters need to be rear hub motor with derailleur.

Another big plus for middrives is standardized interchangeable batteries. Bosch are leaders here with 3 types, rack, powerpack and powertube. Rest offer combinations of standard and bike specific batteries. If you only own one bike it doesn't matter, but for 2 or more in household being able share batteries is big plus. Wife and I have totally different bikes and motors (both bosch) but we can share batteries on long ride, alternatively I borrow hers for bih MTB rides. If I get trekking bike we'll have spare battery (MTB's) for touring.

 

[Bruce Arnold]

From Bicycling Magazine review of the Mid-Drive Specialized Womens Turbo Vado 3.0

https://www.bicycling.com/bikes-gear/a19850892/specialized-womens-turbo-vado-3-0-e-bike-review/


"Acceleration is smooth and immediate—a key strength for e-bikes. Getting a quick jump from a full stop gives a rider more confidence when riding in traffic. When you’re shifting gears or putting more power into the pedals, there’s none of the surging that can afflict some e-bikes with a herky-jerky feel. The lack of lag and the smooth ramp-up in power boosts helped the bike fly up hills with a nearly effortless feel (not all e-bikes do this, by the way—on some, hills still feel like work). The bike handles intuitively, without feeling like a behemoth in fast or sharp turns, and feels stable on steeper descents."

I had a chance to test ride the men's 6.0 ; I concur .

I believe the herky-jerky feel is due more to cadence sensors than to mid-drive vs. hub drive. My CCS has both cadence and torque sensors, and provides a very smooth, intuitive feel.

 

[JRA]

"Another big plus for middrives is standardized interchangeable batteries. Bosch are leaders here with 3 types, rack, powerpack and powertube. Rest offer combinations of standard and bike specific batteries."

I realize you and your wife can share batteries, as long as they are Bosch, and both one of the three types. Hopefully going forward Bosch will retain this standard. A Bosch battery will never interchange with another manufacturers battery docking/BMS type though and there are many different systems out and more coming as well as better chemistries. I personally don't see any Industry standards in play.

I interchange my open source type battery between my hub motor bike and mid drive and that to me is a big plus. In fact all my bikes will soon share the same battery dock and plan to add a 13.5ah and a 17.5ah to the mix here soon. With the two bigger batteries I will be able to do the century from PDX to the Coast on my hub motor bike(s). The 10ah battery I already have will exist mainly on my mid drive mtb as I get about 3.5hrs of trail time out of it and that is usually enough. But I can easily put on one of the bigger batteries for more epic adventures.

This is a pic of a nasty little climb (the lower shaded part is over 20%) that I can achieve on either my DD hubs or mid. Admittedly the mid, as it is on a mtb with 15psi in the tires, is more tractable but the 40c tires at 35psi made it up no problem, the front wheel drive aspect of my road bikes works really well in this type of situation.

 

[Captain Slow]

I haven't read the whole thread but I'll respond with my experience to the OP with his original question.

My first ebike was a Haro with a Bionx conversion kit. I did not really like the bike much at all. It was heavy, the weight distribution was poor, handling was not great due to the lousy weight distribution. It was limited to 32 km/hr, and didn't get me to and from work much faster than if I took my road bike. It was not a great experience and I sold the bike within a year. I told myself it I got another ebike it would definitely be a mid-drive.

I wanted a mid-drive for better weight distribution, hill climbing ability and to make changing the rear tire much easier.

In 2016 I started looking at ebikes again and really wanted a mid-drive. I loved the Trek Super Commuter 8+, but did not want to spend that much money. I also wanted a class 3 because getting a bike limited to 32 km/hr. was just something I didn't want.

I looked and looked and you won't be surprised that I ended up concluding that the Juiced Cross Current S (a hub drive) was the best value out there. The CCS is so much better than the Bionx based bike I had. I still fret about getting a flat on the rear and having to change the tire. Another nit with the bike is the rear hub is 175 mm wide so the chain stays are rather wide. The short wheelbase on the bike makes it handle better, but it also means I kick the chain stays every so often while I'm pedaling and that is a pain.

Independent of hub/mid drive is that the seating position is too upright. I can't really take full advantage of the motor because I catch so much air sitting upright that at 40 km/hr. and above the battery drain is really fast. I really wish that I could have a more aero position.

After owning two ebikes I think my next one will be a kit so I can build what I want. I think about 400 watts is all I need, but I like a bigger battery for range and the ability to ride faster. I'll likely go with a smaller hub motor but a battery that is around 700 to 900 watt hours so I can go further or faster. I really want a lighter ebike with narrower chainstays.

There are more road ebikes coming to market so I won't rule out a factory bike.

 

[Chris Hammond]

I can't really take full advantage of the motor because I catch so much air sitting upright that at 40 km/hr. and above the battery drain is really fast. I really wish that I could have a more aero position.

Have you tried flipping the stem on the handlebars to angle down instead of up? This will drop your bars a bit. Its my plan. If this is still not low enough, you can get a longer stem, or one with more angle than the stock 7% one and then angle it down as too.

 

[Captain Slow]

By all accounts, this is true for DD hubs - as long as you keep it dry. Geared hubs - not so much.
But then, 1.5-2K miles is not unheard of, even for a geared hub. Depends on how and where you ride, too.

Bafang hub costs from $200 online and is not terribly difficult to swap with exactly same motor that has just died. Bafang mid-drive costs roughly 2 times more. Bosch... let's not go there ...

After 2K miles the cost of battery replacement will dwarf the "hub worries", if battery will even last that long.

Isn't the battery replacement largely independent of drive system? Perhaps the mid-drive is a bit more efficient and the battery will last slightly longer. Only 2k miles for a battery? That is shockingly low. I mean if you use say 15 watt hours a mile and your battery is say 600 watt hours and assuming you don't drain the whole battery then say you get 30 miles per charge. If you get say 500 cycles and I think that's conservative then that's 15k miles.

 

[Captain Slow]

Have you tried flipping the stem on the handlebars to angle down instead of up? This will drop your bars a bit. Its my plan. If this is still not low enough, you can get a longer stem, or one with more angle than the stock 7% one and then angle it down as too.

I definitely plan to buy a longer stem and probably even a negative rise, but that still isn't going to come close to a road bike position that is much more aero.

 

[Captain Slow]

Asher,
Here's a few for reference. http://www.ebikes.ca/learn/why-hub-motors-are-awesome.html See item #2
http://electricbikeblog.com/hub-motor-or-crank-drive-motor/ See the end of the article.

Also you can read plenty of forum posts about broken chains, cassettes, etc. Especially on built bikes where owners are using higher power motors. I was initially planning on a BBSHD mid-drive build for my commuter. Glad I researched before I jumped in.
Luna cycles for example offers the BBSHD motor kit with a "Ludacris Mode" of up to 2500W. The drivetrain components were never designed to withstand those kind of forces.

Hence why Luna does not offer a warranty for the bikes they sell with those kits, and if you want a warranty it's pretty expensive.

 

[Asher]

Another big plus for middrives is standardized interchangeable batteries. Bosch are leaders here with 3 types, rack, powerpack and powertube. Rest offer combinations of standard and bike specific batteries. If you only own one bike it doesn't matter, but for 2 or more in household being able share batteries is big plus. Wife and I have totally different bikes and motors (both bosch) but we can share batteries on long ride, alternatively I borrow hers for bih MTB rides. If I get trekking bike we'll have spare battery (MTB's) for touring.

Bosch also charges twice as much per watt hour and offers half the capacity of Juiced. I know which one I'd choose ...

Captain Slow, I strongly recommend trying out a flat backswept handlebar like the Postino, or Nitto Nittensha. I've been able to get much more aero with it, while the backsweep provides wrist support. After getting mine, I'm going to remove the spacers and possibly flip the stem.

So far, I think the main flaw of the CCS is setting it up like a hybrid when it's advertised as a commuter, plus the RCS is now available for offroading. The stock handlebars and suspension don't really make sense when (I assume) it's almost exclusively used on roads, much like hybrids are.

 

[J Miller]

For touring and eMTB factory middrives are only way to go. Tour needs the extra range that only middrives can deliver. With eMTB is power delivery and most importantly for FS low unsprung mass.

I'm in the midst of planning my first DIY build, and this was my conclusion as well. All of the DIY mid-drives I found had pretty significant shortcomings, not least of which was the lack of torque sensing which I consider essential.

For me though, it has to be DIY because that means I can maintain it myself, just a matter of having the right tools and learning a bit, plus I found that you can improve the efficiency of a direct drive hub system quite a lot with the right setup (FOC controller, torque sensing, slower Kv motors, regen, smaller wheels, etc - it adds up). Plus the only mountainous riding I'll be doing isn't part of my commute, and the paved roads are doable (5-15% mostly).

I need to maintain it myself because I don't own a car, and somehow finding a way to cart a bike 50+ miles to the nearest qualified shop to fix a propietary system is out of the question (I live in the States). Already learned that one the hard way the first time I tried to get into e-bikes several years back.

Cruising and commuting then there not lot in it, comes down to personnel preference. Middrives can be lot lower maintenance commuters especially with IGH enclosed chain cover or belt drive. Most of hub commuters need to be rear hub motor with derailleur.

Granted I'm still waiting on parts to do my first build so take this with a grain of salt, but from my experience with riding and maintaining regular bikes my whole life (I don't own a car), more moving parts always means more maintenance.

Mid-drives have the most moving pieces and single points of failure of any ebike motor setup, and it makes the drive-chain a single point of failure. Using a high-end system like Bosch will obviously mitigate that a lot, but the same is true for high-end hub bikes like the Stromer. IGHs can be used with front hub setups as well.

As a side note, I'd rather have a derailleur than IGH, despite the derailleur obviously needing more maintenance: I can fix or replace a derailleur easily myself, I can't do that with an IGH.

 

[tomjasz]

Hence why Luna does not offer a warranty for the bikes they sell with those kits, and if you want a warranty it's pretty expensive.

Because some of the bikes are a clear violation of Federal as well as states laws if ridden as fully capable. Luna expects YOU to be the mechanic.

 

[tomjasz]

Not my experience. I own 5 eBikes, 3 geared rear hub, 2 Bosch mid drive. The only failure I've had was a geared rear hub. A Hall sensor failed in the Bafang at 1,682 miles. The other 2 rear hub bikes have less than 100 miles each. One is new the other was when one of the adult kids come home for a ride. That hasn't been too often. The 2 Bosch mid drives have 1,800 and 1,700 miles. No issues with either.

Bafang, better than the clones, but nowhere near MAC or BMC.

 

[gv1]

High End TDCM hub drives rock. They meet Calif. Class 3 performance with comfortable rider pedelec input, same for climbs. And they are durable, reliable, and offer a well integrated PAS. But, cost more.

 

[keithd]

High End TDCM hub drives rock. They meet Calif. Class 3 performance with comfortable rider pedelec input, same for climbs. And they are durable, reliable, and offer a well integrated PAS. But, cost more.

How are these drives when peddling without power?