Mid drives vs Hub drives ???

[Browneye]

ebikes.ca - I just put this in my cart. $705 for the hub and wheel kit is a bunch of $$. Add $350 to $450 for a battery and we're getting up to the price of a new ebike like a Aventon Pace. I can save $60 by lacing the wheel myself - likely could manage that, have done motorcycle ones without issue. Everything is in stock.
Seems like this is a different Bafang IGH than what is sold elsewhere - like a compact version or something.

EDIT: Oh, now I see this is a cassette hub, we have a freewheel cassette, so add a 7-ring one for $20.
I guess that's do-able.

Rear G310 Kit, Advanced PAS, Custom Build Motor Winding 1 x MG310_Std Include Rim? 1 x Rim275_Alex Include Spokes? 36 x Sapim Strong 13-14g Butted Spoke, Black Include Wheel Build? 1 x WheelBuild Controller (Baserunner Requires Downtube Battery) 1 x Baserunner V3 Cycle Analyst 1 x CA3-DP Include Auxiliary Input (for changing presets or limits) 1 x CA3_DAux_Slim Pedal Sensor Type 1 x PAS_12P Throttle Choice 1 x T-Lever eBrake Cutoffs? 1 x EbrakeWuxD Include Tidy Wiring Kit? 1 x WireRouteKit

Edit

US$705.40

US$705.40

Remove item

 

[Browneye]

A MAC kit from EM3ev - China, is just over a grand, shipped. Laced up to a nice Alex MD35 rim, and a 14ah shark bat.

 

[harryS]

Browneye, you're paying more for the torque sensor, and the Cycle Analyst. You're getting a G310, which is not an especially powerful motor, but a nice one for a mild mannered bike, with a 20A sine wave controller. Its gears allow it to climb better, but it's still a little motor. $705 CDn is $528 USD, about twice what my last ebike motor/controller cost ($275 USD), but that was a cadence sesnor.

The entire RAD and Voltbike community are riding ebikes with cadence sensors, as are about 10 million people in China. Most of the six+ ebikes I've converted use KT controllers with 5 level PAS. Whatever they do on their cadence sensors feels pretty natural to me. Above 10 mph, I can find a pedal speed and a gearing where I'm getting assist and I know I'm doing some work. Below that, I'd have to turn off assist, because cadence sensors cannot operate well at slow speeds like a torque sensor. You probably want a torque sensor for certain types of trail riding, etc. Maybe no assist and a throttle works better there too.

Anyway, if you're just reading about ebike features, everything sounds great, but you have to really experience them to see if you really need them.

And yes, an internet import is often less than buying just the motor/battery.

 

[Browneye]

Browneye, you're paying more for the torque sensor, and the Cycle Analyst. You're getting a G310, which is not an especially powerful motor, but a nice one for a mild mannered bike, with a 20A sine wave controller. Its gears allow it to climb better, but it's still a little motor. $705 CDn is $528 USD, about twice what my last ebike motor/controller cost ($275 USD), but that was a cadence sesnor.

The entire RAD and Voltbike community are riding ebikes with cadence sensors, as are about 10 million people in China. Most of the six+ ebikes I've converted use KT controllers with 5 level PAS. Whatever they do on their cadence sensors feels pretty natural to me. Above 10 mph, I can find a pedal speed and a gearing where I'm getting assist and I know I'm doing some work. Below that, I'd have to turn off assist, because cadence sensors cannot operate well at slow speeds like a torque sensor. You probably want a torque sensor for certain types of trail riding, etc. Maybe no assist and a throttle works better there too.

Anyway, if you're just reading about ebike features, everything sounds great, but you have to really experience them to see if you really need them.

And yes, an internet import is often less than buying just the motor/battery.

Well, it's in USD, so it's $705.
I'm just not familiar with the G310 IGH.

I've ridden the Bafang 36v 350 in a Pace 350, and a Pace 500 - that's a 48v 500w. I thought the 36v would be plenty for the wife's bike. Probably me too, but didn't really spend much time on either - just a couple of loops around the building parking lot.

I had no problem with the cadence sensor - used pas 0 and pas 1 to try it out. The 500 came on pretty strong, the 350 seemed smoother. Frankly I didn't think the 350 would be nearly enough but was quite surprised with how it picked right up and put me at 12-15mph. I'd be happy with the 20mph speed limit, no problem. We are not commuting with our bikes, nor trying to keep up with traffic.

Unfortunately I don't know anything about the 'cycle analyst'. Seems to be a fancy display. It's $100 at EM3ev. I'd be happy with a speedo , a charge state, and the pas level. Thumb throttle is fine, although a half-twist seems like it would be easy to use.

I also find it interesting that Greenergy is an ebay and aliexpress seller, but they're selling Bluenergy marked rim with their kit, and Bluenergy is another big seller in both places as well. Incestuous industry I guess. I'm about ready to buy something off ebay just for the convenience and their backup on the transaction.

I really think a 36v 500w drive would be fine, 48 would some extra. Seems prices are still coming down, at least on batteries - 48v 14ah shark pack about $300 now. 36's are even less.

EDIT: Oh, the photo shows the torque sensor but it's not in my shopping list - just a pas sensor.

48v 500w with pas 0 and throttle would likely be just about right.

 

[bob armani]

I live in São Paulo, Brazil and have a Stromer ST1 with the 14.5amp battery (the gold battery). The city has many hills and I think there are some hills more steep than the one from New Zeland. Sometimes I cannot go up the hills pedaling and I have to walk the bike which is a lot of work, since the ST1 weights a lot. I am looking to buy a Riese and Muller GX Rolhoof HS, but after reading all the pages of this thread I am not sure anymore. Also, I saw that the R&M has the Bosch HS performance engine with only 350W but 65NM of torque? Whereas the Stromer ST5 has 850W and only 48NM of torque. Are these torque ratings correct? Anyone has used an ST5 on a steep hill? Anyone here has ridden the ST5 and the Riese and Muller? I would love to know how they compare. Also, the roads here are TERRIBLE. The asphalt is completely uneven and full of pot holes, so are middrives better? The are some good places with bike lanes, but since they bike lanes do not connect the whole city, sometimes you have to get out and use regular roads that are pretty bad (like the one in the picture). When I have to leave the bike lanes, my body suffers, because the ST1 has only the front shocks.

Hi Ricardo-I spent some time in Sao Paulo and also experienced some of the same problems with bike infrastructure as you have described. Staying on dedicated bike lanes (for most of the commute) to get from point A to point B was never an option. Using sidewalks was also not an option in congested areas with a lot of foot traffic. Using various streets/roads to bike on was just too dangerous due to traffic congestion as well. Like others have mentioned, it would be best for you to have a mid-drive to handle those very steep inclines throughout the city. Having a motor with 60-80 NMs of torque would be ideal found in Yamaha/Bosch/ Bafang etc mid drives. I would also have a full suspension or a quality suspension seat post as well. If I was biking in those same areas, I would just get a quality made F/S eMTB knowing that the bike is made for steep inclines with at minimum 500-600wh battery. As indicated by others, the hub drives just are not ideal for the type of terrain you are currently riding. Good Luck!

 

[tomjasz]

A MAC kit from EM3ev - China, is just over a grand, shipped. Laced up to a nice Alex MD35 rim, and a 14ah shark bat.

I have had kits from both. The eBikes.ca setup is much nicer. Grin has worked with Bafang to tweak their kits. It’s a difficult process. Not understanding the nature of the beast is at the heart of your confusion. Personally I’d do a kit from eBikes.ca and a battery from EM3ev. MAC kits have old style JST connectors. I really dislike them. The eZee kits are sweet. Use the motor simulator. https://www.ebikes.ca/tools/simulat...wheel=650b&axis=mph&autothrot=true&throt=83.2

Motor Simulator - Tools

Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...

www.ebikes.ca

 

[Browneye]

This Bafang IGH in a conversion kit is listed as "Rear Hub Motor Conversion Kit 48V 500W Ebike".

Can I run it with a 36volt battery? Or is the controller different? Or would it have to be reprogrammed somehow?
And if it would run on 36v would it then be rated as 350w or 250W? How does this affect power - i.e.; nm?
I'm guessing the amp setting would need to be increased if you wanted 350w with 36volts, otherwise it would drop to 250w. Do I have these numbers confused? Cuz I'm sure confused!! LOL

I have had kits from both. The eBikes.ca setup is much nicer. Grin has worked with Bafang to tweak their kits. It’s a difficult process. Not understanding the nature of the beast is at the heart of your confusion. Personally I’d do a kit from eBikes.ca and a battery from EM3ev. MAC kits have old style JST connectors. I really dislike them. The eZee kits are sweet. Use the motor simulator. https://www.ebikes.ca/tools/simulat...wheel=650b&axis=mph&autothrot=true&throt=83.2

Motor Simulator - Tools

Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...

www.ebikes.ca

Thanks for this. Yeah, I really like they way they explain what they have and how they got to it. I really like that mini geared hub setup - REALLY! But gee, it's about $650 to get it here and I would have to build the wheel myself. OUCH!

Jason at ebikes.ca suggested that if I liked the Pace 350/500 the G310 would be perfect. The Ezee motors are jump in power for sure.

 

[tomjasz]

The specs have all your answers.

why wouldn't you pay for a wheel build by them? AGAIN, use the motor simulator to compare. You can simulate 36V and 48V batteries!

 

[Browneye]

The specs have all your answers. View attachment 39836
why wouldn't you pay for a wheel build by them? AGAIN, use the motor simulator to compare. You can simulate 36V and 48V batteries!

I'm asking cuz the specs don't mean much to me - I'm not familiar with what they mean or what they do. And the charts and graphs look all Greek to me as well. So that's why I was asking. Seems to me controllers have to be 'told' they are dealing with 36 or 48 volts, and how much amps to provide - so I wasn't sure about using a different voltage battery from the product description of the hub.

I very well could have them build a wheel - another $60. Now we're over $700 and still need a battery. At some point, money-wise, it starts to not make sense and just go buy a new built bike at my local bike shop - with a known quantity/performance window. Then it's under warranty, no building required, just plunk your $$ down and ride away. LOL

The other reason I'm asking is for options - likely the 48v 500w would be just fine. The whole conversion kit with 48v 12ah battery and a laced 27.5 wheel is $659 shipped from Bluenergy. Nearly half of a kit from ebikes.ca. Same for a mid-drive from Luna - also about $1100 with a battery by the time you get done adding in all their add-ins.

A new Aventon Pace 500 is $1350 plus tax. It's a really nice e-bike all ready to go! Add $200 for a 17ah batt. And she could probly get by with the Pace 350 - $990.

 

[tomjasz]

Well if that's the case and you're not willing to have a fairly steep learning curve, then by all means DO NOT KIT BUILD! Doing a kit especially a higher end kit IS NOT cheaper than any number of bikes, like RAD, Juiced, and Biktrix. BUT those bikes also put you in charge of supporting and repairs and troubleshooting. Save up your dollars and go to an LBS with eBikes.

There are much less expensive kits, but they require even more research and tools to sort through a build.

If you were my customer, I'd dissuade you from kit building. ALL the information you'd need to learn a bit of "Greek" is in forums and on sites like ebikeschool.com

I have a Grin controller and it "sees" what voltage I am using. 36V or 48V. I have other less expensive controllers that do the same. Run on 36V or 48V. Bluenergy is over pried for what it is. No name wheel and these Aliexpress direct stores often send crappy wheel builds.Then what? Suddenly that great lower price climbs! I've watched it happen.

So yes, do yourself a favor, buy a finished bike. Quite honestly based on your input here, I'd not want to sell a kit.

EDIT! Don't forget that you'll need some tools if you do a mid drive. Add another $50.

 

[Browneye]

Well if that's the case and you're not willing to have a fairly steep learning curve, then by all means DO NOT KIT BUILD! Doing a kit especially a higher end kit IS NOT cheaper than any number of bikes, like RAD, Juiced, and Biktrix. BUT those bikes also put you in charge of supporting and repairs and troubleshooting. Save up your dollars and go to an LBS with eBikes.

There are much less expensive kits, but they require even more research and tools to sort through a build.

If you were my customer, I'd dissuade you from kit building. ALL the information you'd need to learn a bit of "Greek" is in forums and on sites like ebikeschool.com

I have a Grin controller and it "sees" what voltage I am using. 36V or 48V. I have other less expensive controllers that do the same. Run on 36V or 48V. Bluenergy is over pried for what it is. No name wheel and these Aliexpress direct stores often send crappy wheel builds.Then what? Suddenly that great lower price climbs! I've watched it happen.

So yes, do yourself a favor, buy a finished bike. Quite honestly based on your input here, I'd not want to sell a kit.

EDIT! Don't forget that you'll need some tools if you do a mid drive. Add another $50.

Thanks. Makes perfect sense. I'm getting there...I was hoping there would be a good conversion option for the Roll in particular - it's a really nice bike. But yeah, spending $1200 to convert it makes zero sense to me. And I agree about the bluenergy thing based on wheel lacing how-to at Grin. Lots of broken spokes out there, even on the factory built bikes. In my entire lifetime I've never broken a spoke on a bicycle. [shrug]

 

[tomjasz]

, spending $1200 to convert it makes zero sense to me.

But for many of us building was the best alternative. We had bikes we really liked and weren't willing to give up. When I built my first mid drive there wasn't a single crank forward/Flat foot eBike on the market. I continue to build to get EXACTLY the features I want most. But it was a fairly frustrating first few months.

 

[Browneye]

>snip
But it was a fairly frustrating first few months.

Simply not why I ride bicycles. I appreciate your candor though.

 

[Mass Deduction]

Despite what others have suggested, I think this is a pretty bad article that is not fair or balanced. Here's why I think that...

[...]
2) Less stress and wear on drivechain
With a hub motor bike, the use of the motor lessens the mechanical wear and tear on the chain, cogs, and derailleur system, since it decreases pedal stress that the rider would otherwise put on the transmission. A mid-drive motor does the opposite, putting much more force on the chain and cogs with the motor propulsion now added on top of the rider's input. A normal bike chain drive is fairly robust and can usually handle this extra load without failure, but will wear out at a much faster rate, requiring more vigilant attention to chain stretch, cog wear, shifter alignment etc.

I think this section of the article is not very balanced. What is stated here is true, but not the whole story IMO. A mid-drive motor does wear the chain more quickly, but you can measure and predict that wear. A hub motor is more likely to get a broken spoke, and an unpredictable problem like that is much less desirable IMO. Also, they make hardened e-bike chains these days that wear out much more slowly in high-torque applications. In fairness this article appears to be older than the availability of those chains (I started seeing them in 2017), but that suggests the article may not have been updated sufficiently frequently since then.

I'll take having to buy hardened chains over having to deal with broken spokes. Any day.

3) Ability to use internal gear hubs (IGH)
This is somewhat related to the above point, but one of the great innovations in bicycle hardware in the past decade has been the production of compact internal gear hubs that are 7-14 speeds with wide gear ranges. With a few exceptions (Rohlhoff and the original Nuvinci N171) these hubs are not rated for the extra stress of a motor drive and will usually have a short service life with more than an extra couple hundred watts from a motor. If you want to use a mid-drive with an internal gear hub, be sure to check whether the hub is rated for tandem and/or cargo use, most explicitly say no.

This actually seems to be an advantage for mid-drives, since a front hub motor is not an application I would recommend (see below for why). A rear hub motor is not typically also going to be internally geared! Since more than a few brand name mid-drive e-bikes come with internally geared rear hubs, mid-drives seem to be the ideal motor for those who want to go internally geared.

4) Higher peak power capability
The transmission through your bicycle drivechain also limits the maximum motor power that can be coupled to the wheels. Power levels in the 250-750 watt range are usually fine just with increased wear and tear, but when you are looking for multiple kW of power then you start seeing catastrophic failures with snapped chains, sheared freewheels, broken spokes etc. A hub motor with a properly coupled torque arm has no such limitation.

??? Wattage is not the be-all, end-all. Anyone who has replaced their incandescent lightbulbs with LED lightbulbs knows this. A 10W LED lightbulb will produce more light than a 60W incandescent, despite one being 6x the wattage. Look at the Shimano 6100 motor, it has 25% more range at 20% more torque (!) than the Shimano 6000 motor on the exact same battery. The wattage didn't change, but the internal efficiency did.

Brand-name mid-drives tend to be lighter weight. Most brand name mid-drive city bikes are 40-50 pounds, whereas similarly-specced hub motor city e-bikes often weigh 55-75 pounds. It's possible for a mid-drive e-bike to be more efficient at a lower wattage due to more efficient engineering, less rotating mass, and lighter overall weight. Granted this article is ostensibly talking about hub motor kits vs. mid-drive kits, but some of their statements are more generic than that, and this thread is more generic than that, so I feel it's important to state this lest people apply these statements to OEM mid-drives as well.

5) Potential for regenerative braking
With a direct drive hub motor or a geared hub motor that has a locked clutch, the motor can act as a perfectly controllable brake that isn't affected by rain, pad wear, cable adjustment or anything like that. In a similar manner to how a hub motor reduces wear and maintenance on the pedal drive chain, it can reduce and even eliminate brake pad maintenance as well. You can easily do 90% of your braking electronically with only the odd emergency stop needing the mechanical engagement. On a mid-drive motor, there is really no potential for regen (unless of course you electrify a fixie, but we don't see much of that).

I've ridden BionX systems with regenerative braking. Given they were much heavier and less efficient overall, my sense was that the amount of regenerative braking was less than the extra range you'd gain just by switching to a lighter weight and more efficient e-bike. Brake cable adjustment? I think hydraulic disc brakes are the right choice for most people, especially now that they're very inexpensive. And disc brake pads last a long time and are very inexpensive so brake wear is mostly a non-issue, whereas regenerative braking adds wear and tear onto the motor which the article doesn't even discuss. Talking about brake wear without also talking about motor wear doesn't seem fair and balanced.

6) Ease of installation
Admittedly the BBSXX systems and clones are pretty straightforward to install if you have bottom bracket removal tools and crank tools. But nothing gets quite as easy to fit as a front hub motor, where you are just taking off the original wheel and replacing it with a motorized one. In general we wouldn't emphasize this too much, as the time spent installing any conversion kit is way less than the time you save from riding it and you should install the system that is right for you. If you are concerned about installation and the facility of moving the assist to different bicycles and such, it's hard to top a front hub motor for minimal hassle.

I've seen multiple fork failures from front motor kits. Forks aren't designed for that kind of weight and torque in the wheel. It's worth remembering that if you have a warranty on your bike, you void your warranty by installing any kind of kit (I've never seen a bike manufacturer that warrants adding an e-kit onto a muscle-motor bike). One of the reasons for this is that the parts aren't designed or engineered for those stresses. A rear hub motor is essentially being held in place by four arms, whereas a front hub motor is only being held in place by two arms which can increase the risk of failure. An e-bike designed, engineered, and warrantied around a front hub motor is a different story of course.

[...]
8) Simpler operation with shifting
For a mid-motor to work well the rider needs to shift through the gears as they speed up and slow down, and similarly back off on the motor power while shifting to avoid seriously harsh shift transitions. There are shift sensor products to make the latter automatic, while there is nothing you can do if you come to a stop in a mid-drive system and forget to downshift first. The motor will start off in a high gear with low acceleration and efficiency. For regular cyclists this is probably no issue, but for those without that background, the simplicity of not having to shift gears all the time is one big appeal of an ebike. The rider can generally leave the bike in a high gear and use the hub motor to quickly get up to speed so there is no need to go through the motions of downshifting and up-shifting at each stop and go.

I've seen so many hub motor e-bikes that were inexpensive 7-speed setups (both OEM and kit) that shifted absolutely terribly through no fault of the motor. In general, mid-drive e-bikes tend to be higher-end so tend to shift better, despite the mid-drive motor. Given torque sensing is becoming pretty de-rigeur for mid-drive OEM (and increasingly frequent for kits from what I understand), I think this is the case of an article in need of an update.

It was an interesting article and I appreciate it being shared here. I've bought products from ebikes.ca, so perhaps I'll send an email off to them with my observations about this article needing an update.

 

[tomjasz]

While I have some general agreements with the article, I find some glaring misrepresentations in your response.

Many heavy duty, EBike designated chains, Connex Whipperman for example, won’t run on narrow side chainrings popular with mid drive users.

Front drive hub motors have very safe and practical applications.

Broken spokes are rare in properly built wheels with quality rims and spokes. I’ve seen a fair number in mid drives. And never any unusual rates with proper hub builds.

I think you miss the point regarding power levels. Justin pointed to the advent of 3000W mid drives. They are hard on drive systems. Very hard.

BIONX is an example of one regenerative braking system. My steel fork, front DD using a Grin controller and CA3 is extremely effective. As a Grin user you may have utilized that feature. BIONX is no longer available and maybe not a good representation of how it should have been implemented?

Visit a forum with higher voltage mid drives and read about disc pad wear. Significant for some unless upgraded to high end systems.

Higher end bikes fo have great performance and are fabulous bikes, but pretty anemic for much of the market. Bafang popularity clearly demonstrates that.

Your post is a great counterpoint, but I think you make judgements that leave many holes and exceptions. Some, like front hubs glaringly narrow. Front drives can be very successful build methods. Albeit limited, low power dual torque arms and steel forks, but still no reason to pitch the baby with the bath water.

I ride them all and each has a spot in someone’s garage. I won’t bore the thread with my list...

Thanks for the excellent discussion....

Oh, I think it’s worth noting the discussion was born out of requests for Bafang mid drives. Not those high end low wattage but classy Bosch and their ilk.

As always YMMV!

 

[Feliz]

Why do you waste your time Tom?

 

[tomjasz]

Why do you waste your time Tom?

Yeah, damn eBike hugger.

 

[indianajo]

Lots of broken spokes out there, even on the factory built bikes. In my entire lifetime I've never broken a spoke on a bicycle. [shrug]

I've owned 2 drive wheels with hub motors. Neither has broken a spoke over about 4000 miles. I broke one schwinn spoke 20 years ago. The 1000 W 48 v DD hub motor cost $189 with controller, throttle, brake handles, freewheel. The 1200 W 48 v geared front hub cost $221 with controller, throttle, PAS sensor, brake handles, brake calipers & disks. I like having weight on the front, the unpowered MTB's I rode previously threw me over the handlebars on my chin thrice after the wheel whipped sideways on obstructions. I prefer the geared hub for many short steep hills, up to 15%. People in areas with long steep hills should buy DD hub which shed heat better. DD are grade capable but use more electricity on them than geared hub. I pedal unpowered more than 2/3 the distance so I don't want a draggy mid drive.
I changed to IGH (SA 8 speed) before the electric conversion, and that added 15% to my elapsed time over derailleur. You spin all those planatary gears all the time. With the front hub motor I can have 8 speeds on my cassette (11:32) that came with the bike instead of 7 speed (14:28) that came with the DD drive. No 8 speed freewheel on the DD motor would fit the dropout.

 

[AHicks]

Despite what others have suggested, I think this is a pretty bad article that is not fair or balanced. Here's why I think that...



I think this section of the article is not very balanced. What is stated here is true, but not the whole story IMO. A mid-drive motor does wear the chain more quickly, but you can measure and predict that wear. A hub motor is more likely to get a broken spoke, and an unpredictable problem like that is much less desirable IMO. Also, they make hardened e-bike chains these days that wear out much more slowly in high-torque applications. In fairness this article appears to be older than the availability of those chains (I started seeing them in 2017), but that suggests the article may not have been updated sufficiently frequently since then.

I'll take having to buy hardened chains over having to deal with broken spokes. Any day.



This actually seems to be an advantage for mid-drives, since a front hub motor is not an application I would recommend (see below for why). A rear hub motor is not typically also going to be internally geared! Since more than a few brand name mid-drive e-bikes come with internally geared rear hubs, mid-drives seem to be the ideal motor for those who want to go internally geared.



??? Wattage is not the be-all, end-all. Anyone who has replaced their incandescent lightbulbs with LED lightbulbs knows this. A 10W LED lightbulb will produce more light than a 60W incandescent, despite one being 6x the wattage. Look at the Shimano 6100 motor, it has 25% more range at 20% more torque (!) than the Shimano 6000 motor on the exact same battery. The wattage didn't change, but the internal efficiency did.

Brand-name mid-drives tend to be lighter weight. Most brand name mid-drive city bikes are 40-50 pounds, whereas similarly-specced hub motor city e-bikes often weigh 55-75 pounds. It's possible for a mid-drive e-bike to be more efficient at a lower wattage due to more efficient engineering, less rotating mass, and lighter overall weight. Granted this article is ostensibly talking about hub motor kits vs. mid-drive kits, but some of their statements are more generic than that, and this thread is more generic than that, so I feel it's important to state this lest people apply these statements to OEM mid-drives as well.



I've ridden BionX systems with regenerative braking. Given they were much heavier and less efficient overall, my sense was that the amount of regenerative braking was less than the extra range you'd gain just by switching to a lighter weight and more efficient e-bike. Brake cable adjustment? I think hydraulic disc brakes are the right choice for most people, especially now that they're very inexpensive. And disc brake pads last a long time and are very inexpensive so brake wear is mostly a non-issue, whereas regenerative braking adds wear and tear onto the motor which the article doesn't even discuss. Talking about brake wear without also talking about motor wear doesn't seem fair and balanced.



I've seen multiple fork failures from front motor kits. Forks aren't designed for that kind of weight and torque in the wheel. It's worth remembering that if you have a warranty on your bike, you void your warranty by installing any kind of kit (I've never seen a bike manufacturer that warrants adding an e-kit onto a muscle-motor bike). One of the reasons for this is that the parts aren't designed or engineered for those stresses. A rear hub motor is essentially being held in place by four arms, whereas a front hub motor is only being held in place by two arms which can increase the risk of failure. An e-bike designed, engineered, and warrantied around a front hub motor is a different story of course.



I've seen so many hub motor e-bikes that were inexpensive 7-speed setups (both OEM and kit) that shifted absolutely terribly through no fault of the motor. In general, mid-drive e-bikes tend to be higher-end so tend to shift better, despite the mid-drive motor. Given torque sensing is becoming pretty de-rigeur for mid-drive OEM (and increasingly frequent for kits from what I understand), I think this is the case of an article in need of an update.

It was an interesting article and I appreciate it being shared here. I've bought products from ebikes.ca, so perhaps I'll send an email off to them with my observations about this article needing an update.

Like Tom, I struggle with some of the responses as well. I do agree though, that some of the article is dated.

I'm a big fan of the rear hubs, and geared rear hubs in particular - as they suit my purposes/way of thinking best. I will not say they are best. I will say the DD and gear drive hubs both have their fans for good reason, just like the mid drive fans. With an open mind on the topic, it seems clear to me there is not one of these drive systems that are clearly superior for all applications. When you see somebody saying anything differently, the term "fan boy" comes to mind. The type that are trying to convince the rest of the world they made the right decision when they purchased whatever they are espousing as "superior".

The threat of broken rear spokes is no more real than a totally disabled mid drive equipped bike due to some mechanical drive line failure. My choice regarding the likelihood of either situation much different than yours. Who's wrong? Make your choice and live with it, if you can do that, without condemning the other choices as a mistake.

Most that have ridden regen in hilly areas where they are/can be used to an advantage, know that regen is NOT about charging your battery, it's about allowing a controlled decent coming down hills! Sure, your brakes will work to do the same thing, but you like to talk about efficiency, which type braking do you believe is more efficient? You mention wear and tear caused by regen, but fail to mention regen is available to most using only DD hubs. With no moving internal parts, what exactly, is wearing here?

And last, regarding the more economical bikes vs. the more expensive ones. This is more personal preference vs. right or wrong. When riding back and forth to work in your car, or going for a grocery run, you have to notice the different brands of the cars around you. Do you see only the least expensive on the side of the road? Because that is so unlikely, could you not then make an assumption that you don't need the most/more expensive to get the job at hand done? Could you then take that a step further by comparing the more expensive brands of cars to the rest and determining the more expensive brands are actually in the minority? -Al

 

[GregGritton]

To add to "Mass Deduction"'s deconstruction, one other section about the eBikes.ca "Why Hub Motors" could be misleading when taken out of context:

7) Torque sensors options

Because of the independent propulsion, the hub motor drive leaves any number of sensor technologies available for measuring rider pedal input, including chain tension (BeamTS), rear dropout (TMM4), Rear axle flex (eg BionX), and the many bottom bracket torque sensors (NCTE, Thun, TDCM, Sempu etc.). With a mid-drive, the motor couples through the drivechain so these sensors can'd distinguish pedal power from motor power, and so you are stuck with what the mid-drive system comes with which has so far been pretty limited. Some (like lightningrods and Tongsheng) have a torque sensing, while on the vast majority they are have just a basic pedal cadence sensor.

Now there is no reason why more aftermarket bbs style mid-drive can't have an integrated torque sensor, it's just that so far this mostly exists only on OEM bottom bracket drives like the Bosch. .

The article is totally accurate when talking about older mid-drive kits, but only about kits. Otherwise, the opposite tends to be true. Mid-drives from the major manufacturers (Bosch, Brose, Shimano, Yamaha, and derivatives such as the motors from Giant and Specialized) always have integrated torque sensing, and that torque sensing has been tuned over time. Thus, the torque sensing worked well with every mid-drive that I tried when I was investigating which bike to buy. On the other hand, torque sensors with hub drives tend to be an afterthought. I had tried two, and one (Stromer ST1) was smooth, the other (Raleigh Misceo iE) was less so. Also, there have been reports on the forum of external torque sensors (i.e. those not associated with mid-drives) going bad over time.

Thus, while torque sensing isn't exclusive to mid-drives, it does tend to be one of mid-drive's main advantages.

As always, it is best to ride any bike before you buy to see how it behaves. The proof is in the pudding.