Rear hub or Mid-drive (should I just flip a coin?)

General Discussion about electric bicycles.
laminarflowca   10 µW

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Rear hub or Mid-drive (should I just flip a coin?)

Post by laminarflowca » Aug 20 2019 10:25pm

This is a follow on post from my previous post further down: -Beginner E-bike DIY in Canada (Vancouver Island))

Basically I still can't decide between rear hub and mid drive

Was 99% ready to order a Direct Drive rear Hub for my first project. But part of my brain keeps nagging me that I should get a BBS02 Mid-drive or i'm gonna regret it.

Silly I know but I know that
  • I live in a town with a lot of hills. It's a coastal town with mountains behind.
  • that i'm likely to be more adventurous with the bike than I admit to right now. (I'm telling myself its just for commuting)
  • I have a strong feeling i'm likely to very quickly want to buy a better donor bike (which is unlikely to have 26" rims)
  • Im worried its a lot of money to lay down and regret my choice!

I know the increased stresses on the bike drivetrain using a mid-drive... that I understand they can be more temperamental than a hub, but I think I got a bit swayed when I ended up trying an e-bike this weekend (just a Raleigh bike with 350w bosch mid drive)... but the mixture of gearing and a drive were impressive.

I'm already thinking that my initial donor bike will do for now, but later I might want to swap the drive to a better bike I buy. Now if I choose a rear hub I will limited to a 26" wheel unless I get it rebuilt on a different rim. but a mid-drive I could easier move over.

Yes I know the cheaper Direct Drive rear hub is probably less hassle, more reliable and perfectly capable for my every need! So do I go sensible, or listen to the devil on my shoulder telling me to do it? Maybe I just need talking back to the sensible option.

at least I think I got my Battery sorted. Likely to buy from em3ev.com (unless someone can tell me that's a bad Idea).

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efMX Trials Electric Freeride   100 kW

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by efMX Trials Electric Freeride » Aug 20 2019 11:04pm

do you want a bicycle type ride, then mid drive..
or more moped like?? then hub motor..
(listen to the devil, he's more fun)
some ride & sk8 videos:
metacafe.com/channels/NATAS666DAMIEN
http://www.youtube.com/natas666damien
i have nothing for sale.. :)

Grantmac   10 kW

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by Grantmac » Aug 20 2019 11:05pm

I like mids, just not bafang.

laminarflowca   10 µW

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by laminarflowca » Aug 20 2019 11:18pm

what Mid would you recommend.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by 2old » Aug 20 2019 11:39pm

I've had four years of great service from a BBS02 riding it off road, and my wife, who doesn't ride as much, has had the same excellence from hers. Bafang manufactures almost a million motors a year; they must be doing something correctly.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by Ozzzz » Aug 20 2019 11:58pm

Both? A small DD motor in hub wont cost a lot. If you are going to change bikes you can use the same battery.
I'm not sure if it's an option there yet but (as an alternative) the bafang max /mid drive are cheap and probably also the ultra?
It wasn't much more cost than a home-build for mine in a fat bike. And the ride, so far, is impressive. Smooth, quiet.

That said, it's not legal (here) but my 48v mac mtr bike handles all the hills around home, is still going /unopened for around 4000 miles and the throttle = more fun.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by Grantmac » Aug 21 2019 1:58am

laminarflowca wrote:
Aug 20 2019 11:18pm
what Mid would you recommend.
I misstated, not a BBS series. The integrated ones are ok.
For a DIY I'd go upgraded cyclone from CYC, or else the X1.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by furcifer » Aug 21 2019 7:54am

If I was still living in Victoria I think I'd prefer a mid drive. Some of the hills are a little steep, and it can be wet at times. It seems to be easier to waterproof a mid drive. I had to redo all the gaskets on my Bafang to get it properly sealed but every since I haven't had a problem. Either way you go I think HIGO connectors are something you want to consider.

LeftieBiker   10 kW

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by LeftieBiker » Aug 21 2019 8:19am

The geared hub drive on my Magnum Metro handles hills just fine, but after just a year and 1600 miles it sounds terrible and is getting louder. And the "manufacturer" of course, stopped responding to my emails after I sent them a link to a recording of it. Get the mid drive.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by donn » Aug 21 2019 9:44am

laminarflowca wrote:
Aug 20 2019 10:25pm
Yes I know the cheaper Direct Drive rear hub is probably less hassle, more reliable and perfectly capable for my every need!
What's the issue here? If there's some reason to believe the above may not really be true, and there is something less than satisfactory with the proposed direct drive, then maybe we can get to the bottom of that; specifics would help. Problem getting a new rim on a hub? Not really, any bike shop should be able to do this.

If it's more like you fully accept every word of the above is true, and you just want a mid-drive anyway ... suit yourself. "It's a free country", I guess we can say that even if we're in different countries.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by MadRhino » Aug 21 2019 10:15am

Slow climbing requires a mid drive. Fast climbing is hub domain.

Hubs that you will climb with, require better batteries and bigger controller.

Mid drives are retaining the bicycle feel, while hubs are more moped like, even motorcycle like when high powered.

Hubs, big ones especially, can survive amazing abuse and adverse conditions for a lot of mileage. I have done 30,000+ km with a cromotor and 2 sets of bearings. Dirt and mud, in the winter especially, are very hard on mid drives.

Mid drives can make good jumpers when installed on a good bike, while hubs can only jump one meter with the best wheel build.

Hubs are simple, easy and fast, and require no shifting. Mid drives require shifting: with proper shifting they are more efficient, with stupid shifting they fail.

I guess that should be enough to make a decision, according to your need.
Make it fool-proof, and I will make a better fool.
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Street: https://s20.postimg.org/ewrvugywt/Session_04_2015.jpg
Dirt: https://s20.postimg.org/lbqwr55ml/IMG_0157.jpg

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by markz » Aug 21 2019 10:37am

Also consider the ability to hide a rear hub motor under the rear pannier bags hanging off the rear rack.
There is no hiding a mid drive motor.

sleepy_tired   10 W

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by sleepy_tired » Aug 21 2019 11:22am

Mid drives are retaining the bicycle feel, while hubs are more moped like, even motorcycle like when high powered.
I would pick a small geared hub motor over mid-drive if my goal was to retain 'bicycle feel'.

The reason being that a lot of mid-drives do add additional drag to the pedaling process, modify the bicycle drive-train, and change the 'Q'-factor.. the spacing of the pedals. With a small front hub motor or rear hub motor with freehub/cassette then you really don't have to modify the bicycle hardly any. You can retain all your stock gearing and shifters and whatnot in most bicycles with a hub setup.

If you are looking for just a 'assist' setup setup were you are expected to pedal around then a little hub motor is probably a lot better due to these reasons. As long as you don't mind pedaling up hills then it can still provide a lot of boost. Even a big DD hub motor can work fine with a pedal bicycle if you are willing to pump 20-30 watts through the motor to overcome any sort of cogging effect while pedaling 'unassisted'.

The real big advantage of a mid-drive really boils down to the fact that it can power you up steep hills at a slow pace if you have the gearing for it. So if you want to maintain a lightweight bicycle and don't mind going somewhat slower on hills as long as you don't need to put any effort into pedaling then mid-drive makes the most sense.

Mid drives require shifting: with proper shifting they are more efficient, with stupid shifting they fail.
If it's a good mid-drive then it should be geared to match natural human cadence, which is around 70-120 rpm. If you are pedaling very slow then you are probably going to cause the motor to overheat in most setups.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by HK12K » Aug 21 2019 11:51am

We still talking about converting the Norco Bush Pilot here?

As a relative noob, I'd lean towards a middrive for that bike if it were me. Hardtail plus rim brakes means you're probably not going to want to be travelling at breakneck speeds. You may value being able to maintain a more consistent speed going from flat ground to an incline however, which the gears will presumably help with. From my limited experience you've got to be able to push some serious amperage to motivate a hub motor up some of the steeper hills out there without slowing to a comparative crawl, especially on the tail end of your battery charge. If you build a bike with that much power you're going to be inclined to use it on the flats, which probably isn't the greatest idea.

Full disclosure: I've never owned or even ridden a middrive bike, nor a geared hub. I do however own qs205 hub powered bike and deal with similar hills. I find it lethargic uphill at anything under 80 or so battery amps @72v. 110 battery and 250 phase on the other hand, it scoots up hills, though heat becomes an issue on longer climbs. It'll also lift the front tire and catapult you well beyond the ebike speed limit in the blink of an eye on the flats. Yours would be lighter and would presumably require less power than mine to do the same, but still probably not what you want on an aluminum hardtail mtb with rim brakes.

I guess the big question here is whether you want a pedal bike with electric assist, or an electric bike with pedal assist? If the former, a middrive seems well suited. If the latter, a hubbie, but make sure you can throw enough juice at it otherwise you'll be grinding up hills by force and not by choice (and maybe source a full suspension donor and forego the Norco.)

All IMHO, of course.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by sleepy_tired » Aug 21 2019 12:04pm

It really boils down to how steep of hills you are dealing with and how much effort you want to put into pedaling up those hills.

If the answer to those questions are 'very steep' and 'as littlle as possible'... then mid-drive is the no-brainer goto.

---------

The problem with talking about hills is that virtually nobody actually has any sort of clue what they are talking about. I regularly see people saying 'Oh I have to deal with 20-35% hills'... were if they actually had to deal with those then cars and trucks would have trouble dealing with them and they would be regularly riding on the top 10 steepest roads on the planet.

People confuse 'big and tiring' with 'steep', but it's actually rare to see any hills much steeper then 6-7% on public roads that are of any substantial size. Short hills in neighborhoods, sure.. but nothing that actually matters. Especially in any area that sees a lot of inclement weather. Even on dirt trails long steep hills are avoided because they usually become maintenance nightmares.

There are areas that are exceptions to this.. like some places in mountains or LA, so it's hard to know for sure without actually looking at a map that shows grades.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by Voltron » Aug 21 2019 12:30pm

I'll add my two cents...

If you go any kind of higher power levels, say over 500w, you really should like to tinker around with a bike, and understand how to extract chains that are jammed against things on the trail, how to use quick links, and check things a lot for stretching and cracking, know how to spot a bent derailleur before it destroys itself by jamming into the spokes, and be ready to walk a long way from any number of possible failure points (freewheel pawls shearing, internal cluches, crash damage to motor mounts, etc) .

This is coming from the experiences of installing kits on customer bikes. One snapped his frame in half from the bowing to the right powerful chain pull causes, inside of three test rides I was along for, so I know for a fact he wasn't even pushing it. Several others ditched theirs because of the constant chain and gear cluster wear. Others that were into it and didn't mind that stuff loved theirs.

Hub motors are heavy, and bad for jumping. Aside from that, they're cheap, harder to destroy, and can usually still be ridden after a problem, i.e. with a broken chain or freewheel failure it will still go, and vice versa, usually a system failure doesn't stop normal pedaling.


Some people like the fact that the drawback list for hub motor is so much shorter... Horses for courses.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by dustNbone » Aug 21 2019 1:55pm

markz wrote:
Aug 21 2019 10:37am
Also consider the ability to hide a rear hub motor under the rear pannier bags hanging off the rear rack.
There is no hiding a mid drive motor.
True you can't hide it, but the vast majority of people need to have the presence of my BBS02 pointed out to them.

If you live on the Island, you want a mid drive. Or a really big mean hub.

I carry a chain break and spare links with me, have for all the years I've ridden the BBS02. I've only ever used them to rescue other bikes.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by Grantmac » Aug 21 2019 2:14pm

The other thing I'll say about the Island is this: you are in the land of extremely high quality, extremely cheap full suspension bikes. Don't put the effort into a dead end chassis.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by furcifer » Aug 21 2019 2:55pm

Grantmac wrote:
Aug 21 2019 2:14pm
The other thing I'll say about the Island is this: you are in the land of extremely high quality, extremely cheap full suspension bikes. Don't put the effort into a dead end chassis.
+1 Lot of plans to hit Whistler never manifest. There's a good variety of downhill/fs bikes that would make great ebikes on the island.

I couldn't decide either so I got both a 1500W hub and a BBSHD to mate with a 52V 21ah battery. Both have their own merits and I'd be lying if I didn't say there are times when you're driving one that you wish you were driving the other.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by laminarflowca » Aug 21 2019 4:52pm

I just want to say a big thank you to everyone who has given feedback on this.

Its given me further thought of being honest to myself what I want, the location i live and the project i'm trying to complete.

I have realized reading through this

1. i like the idea of a more powerful Bike experience, rather than a moped style experience.
2. When I drive a car for fun I would choose A manual Gearbox car rather than Automatic. its also how I like to ride my non-powered bike. Always trying to find the right gear for the occasion. (My wife always jsut powers through in too higher a gear!)
3. My donor bike choice has limitations to me that I know is why i'm already looking at the secondhand market for bikes. But im sure I could move a Mid-drive over once a suitable upgrade bike was found.
4. Whichever I choose i'm sure to have an absolute blast.

Im swaying towards a BBS02 750w, likely getting a replacement 42T or smaller replacement Chainwheel. (a tiny part of me is interested in the TDSZ2 as i'm an open source nut and see there is a project to build a open source firmware for that!)

But anyhow I think its tipped the balance toward a mid-drive for my first project.


So thanks everyone who took the time to reply.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by wturber » Aug 21 2019 8:19pm

If you want a practical commuter, then DD hub is probably the choice given the premium that reliability has in this role.

If you want to have more fun farting around doing trails and going up hills, then mid-drive sounds right.

So it seems like you need to get real honest about priorities. Sound to me like you really want a "fun" bike more than a practical commuter.
"Commuter - DC Booster"
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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by docw009 » Aug 21 2019 9:39pm

You can go both ways. Start with an inexpemsive hub motor kit first, around $250 CDN. No need to spend more, and pick a battery that can run it and a mid drive later. If the hub kit satisfies the commute needs, you're done. If you want more hill climbing power. you can always upgrade to a mid drive.

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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by dustNbone » Aug 22 2019 4:56am

For reference, here's a photo of a ferry entering Departure Bay on Vancouver Island.

You could call those mile high rocks in the background "hills" I suppose.
12444457175_2e2f123bb5.jpg
12444457175_2e2f123bb5.jpg (88.09 KiB) Viewed 352 times


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Re: Rear hub or Mid-drive (should I just flip a coin?)

Post by AHicks » Aug 22 2019 7:24am

As one that's familiar with what "coastal" can involve, I can safely say it needs to be geared. When you start talking BIG hills and off road, I'm thinking mid.

One thing that might enter your decision making process is how you plan to keep your speed in check going down hill. That in mind, there's a newer drive system that you don't hear a lot about yet, known as the GMAC. If there's any DIY in you, you might want to look into something like that. It's a geared rear hub with VERY effective regenerative braking. The biggest concern with something like that will be heat build up, so it's not the perfect setup either. That said, with the hills you have to play in available, heat build up will be you're #1 issue beyond ANY bikes ability to get to the top. My thought anyway, FWIW.

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