adlai

While mid drive is generally considered better for hill climb, it seems possible that a hub drive ebike could simply not have any secondary shift system and just use the electrical component as such. So a 250w mid drive with a igh hub vs like a 750w hub drive single speed, which does better? Especially as an igh system itself is like an additional 8lbs

cat0020

How much do you weigh?
How fast do you want to travel up hills?
How much do you want to pedal to help.yourself get up hills?
How much do you want to spend?
All those would help factor what type of Ebike you might want to do sider.
Anything mid-drive is likely for going to cost twice as much as a hub motor with 7-speed drivetrain and you will still be relying on the weakest link in the chain to properly up hills.
Is mid-drive really better.for climbs? IMO, debatable.

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fooferdoggie 

according to grin technologies about the max you want to climb in a hour on a hub drive is 1000 feet. depending on the hills your going to have to put effort into it unless you want to go up slow. on my trek with the newest bosch motor I can go up a 18% grade putting out 400 watts myself at about 13mph. or I can climb it with about 200 or so watts with max assist at a slower speed (it would depend a lot on your gearing) wife and I on out bosch mid drive powered tandem did a short 23% grade. about killed us but we made it it up it. thats about the max I can do on my trek with the gearing I have. but its more of a road bike then a mountain bike. I do have to work at it but it's doable.

2old

There's no comparison between a mid-drive and a hub system for ascending. The mid will climb hills easily that will fry the hub IMO. The only way a hub system can be effective is if it's a powerful motor (2Kw, maybe more) and/or you have good fitness. If you're interested in building a powerful hub, go to endless sphere or you can build an effective mid with a BBS02 (or equivalent) and a mid-90's or so MTB.

cat0020

Knowing how to shift, using the right gearing to climb hills is essential riding skill for any cyclist.
Using the proper gearing on your ebike can allow even the hub-drive ebike to climb just as well as any mid-drive ebike.

IME of owning multiple mid-drive & hub-drive ebikes, conversions & complete ebikes; there is no significant advantage to spending extra money for a mid-drive ebike for general cycling.

Mid-drive ebikes are always limited by the weakest link in the chain, cost more than hub-drive ebikes and the motor causes extra stress & wear on the chain.
Once the weakest link on the chain gives way, you're limited to pushing the bike home or fix the chain on the ride.
At least with a hub-drive ebike you can still throttle your way home without the chain.

Cost wise, complete, capable 750w hub-drive ebike (under $1.5K) are available at the cost of some mid-drive motor conversion kits, without the hassle of trying to mount a motor/battery onto your existing bicycle.

Unless you're an experienced mechanic with proper tools, spending the time to convert a regular bicycle to a mid-drive ebike,
you'll still have a ebike that not designed for the extra power output & weight of a motor plus battery.
You better make sure that the frame can handle the extra weight & brakes are sufficient for the extra speed.

Randoo

Does mid-drive cause significantly more chain problems than usual?

fooferdoggie 

f you have a huge mid drive maybe but with my bosch I tend to get 2000 in winder and 2500 miles without rain on a 10 speed chain. my fist bosch mid drive I got 12000 miles on the drivetrain before the chain ring and cast were toast. never broke a chain. our bosch power e tandem has more wear on the cast then my commuter does but its not huge amount.

cat0020

If you don't know how to shift, any drivetrain can cause more problem while using high power output with the wrong gearing.
With powerful mid-drive motors, chances of wearing out the chain, cassette & chainring are just higher than a hub-motor ebike.
Combined with a throttle, mid-drive motor can easily produce excess wear on drivetrain.
Chain maintenance is very important when the only way to propel your ebike is through the drivetrain.
Hub-motor ebike can get away with less maintenance, dirtier drivetrain do not cause much problem since the power output is not dependent on the chain, cassette & chainring.

Moe Zhoost

You know, most of my hub motor friends bring this up every time that I talk about my mid-drive preference. My answer is "no, not in my experience" and further I can't imagine using just pedal or torque assist with reasonable gear selection would affect the chain significantly.

My question to them is "How easy is it to replace a wheel bearing on your hub motor?". I did this for a friend and the effort required delacing the wheel and splitting the motor shell to isolate the bearing. For most owners relying on a shop, their answer would be "Replace the whole wheel".

To the OP: sorry for the diversion. To answer your question I think you would have to do a side by side comparison using similar bikes with different motor set ups. I'd be wary of using advertised power levels to steer your decision.

Also, an IGH will not add 8 lbs. You have to consider the weight of the entire drive train. Check out the following chart. The difference between the common Deore triple and an Alfine 11 is less than a pound.

Lightest to Heaviest: The Drivetrain Weights

SRAM Force 1X – 2247 grams
SRAM GX 1X – 2273 grams
SRAM NX 1X – 2581 grams
Shimano Ultegra 2X – 2638 grams
Shimano SLX 2X – 2700 grams
Shimano Deore Touring 3X – 2723 grams
Shimano Alfine 11 Speed Belt Drive – 3058 grams
Rohloff 14 Speed Belt Drive – 3125 grams
Rohloff 14 Speed Chain Drive – 3194 grams
Pinion C1.12 Belt Drive – 3310 grams
Pinion P1.18 Belt Drive – 3850 grams

From https://www.cyclingabout.com/weight-...rohloff-bikes/

cat0020

Why would you need to replace a wheel bearing on a hub motor?
The sealed bearings are not exposed to mud, dirt, grease as a drivetrain; the wear on sealed bearings don't occur nearly as much as drivetrain wear of a mid-drive ebike.
Replacing a whole hub-motor wheel likely cost less than some drivetrain on a mid-drive ebike.

2old

There's no way the extra power will not cause slightly more drivetrain wear. However, by shifting properly the increase will be minimal. I used a three-speed cassette 11-17-28 spaced 8-speed (the gears were at the end of the cassette in order to have a straight chainline and reduce chain stretch) for three years of pretty severe off road activity before it needed to be replaced, and am on the second iteration. It's lasted longer since I gave the bike to my son who rides it on bike paths only.

Moe Zhoost

Well, because they are low cost, mediocre quality bearings and they go bad. I've replaced a number of them both on hub motors as well as other hubs that use them. They usually have a seal; rubber or metal on both sides (but sometimes only on one). The seals will inhibit water and dirt intrusion and, more importantly help keep the grease from leaking out. They are in no way waterproof so for all weather commuters they may last a year or so. I'll say that it's remarkable how many miles a rider can happily put on a bike that has a faulty bearing without noticing the slow increase in drag or noise. This certainly does not prove that they are maintenance free.

You're comparing the wear of a single component of a hub to the entire drivetrain of another system? Apples and oranges, my friend. Sealed bearings go bad, cup and cone bearings go bad. So do chains, cogs, freehubs, chainrings, and bottom brackets. It's all a function of the conditions of use and maintenance, not the type of e-system.

Again, you compare apples to oranges. Drivetrains on any bike are subject to wear and tear, and components will need to be replaced. Replacing most drivetrain components should be at an equivalent cost regardless of the type of system. My example of the hub bearing was the exception. If your argument is that drivetrains on mid-drive systems need replaced significantly more often than those on hub motor systems, I can only say that I have not seen this to be true, though it just may so for those riders who overuse their throttles and rarely pedal.

The one advantage of a hub motor is that it will generate electricity when coasting.

cat0020

And just how many hub-motor ebikes have owned to make that determination?
How many hub motor bearing failures have you experienced in how many miles of usage?

You're the one that brought up hub motor bearing failure, not me.
Mid-drive ebikes require the complete drivetrain to be operational to be ridden, hub-motor ebike can be ridden without a battery even installed on a the ebike.
I never said sealed bearing do not go bad, but not as often as you think; at least you don't need to clean the sealed bearings as often as mid-drive motor drivetrain.

Sure any drivetrain on a bike experience wear & tear, but more so on a mid-drive ebike vs hub-motor ebike or regular bicycle.
Regardless of throttle usage or not, the drivetrain is required to have mid-drive motor transfer power to the rear wheel,
but no so for the hub motor ebikes.
If your drivetrain is dirty or lack lubrication, not only does it cause more wear, it also robs power from your mid-drive motor; but not so much with a hub-motor ebike.

Wrong, only direct drive hub motor can allow regen while coasting, and you would still require a controller to be able to collect that generated electricity to be directed back to the battery.
Majority of gear driven hub motor do not have regen capacity.

fooferdoggie 

Yes just like any bike. the hub drive if it did not have a throttle would be the same. a mid drive can be ridden without a battery too.

cat0020

How many hub motor ebikes do you know that does not have a throttle?
Even without a throttle, can a hub drive motor propel an ebike with just cranks spinning without chain? cam a mid-drive motor propel an ebike without chain?

Sure mid-drive ebike can be ridden without a battery, but with extra resistance of the motor & friction in drivetrain.

fooferdoggie 

another myth or at least way overblown. my 2nd gen both motor had a bit but unless you were extremely weak as in 8oz extra effort as I tested it with a Allen wrench once. and a video to show it the resistance is in the extra weight of the bike usually fatter tires and gearing. a hub drives wheel is far more massive so its going to take even more effort to get it spinning. all you need to dp is put the bike in a stand and test it out.

cat0020

Nice try with the deflection from providing answers to my questions.
Still doesn’t change the fact that you need a working drivetrain for a mid-drive ebike to be operational.

fooferdoggie 

yes like any bike thats an issue? same on a hub drive bike if the battery dies or you have an electrical issue or as you said it had no battery installed your are in the same situation if it has no throttle same thing.. So I showed you how little resistance there is and nothing? Most hub drive bikes have fatter tires poor gearing and the rear wheel is crazy heavy.

cat0020

And how many hub motor ebikes have you owned or have you seen without a throttle?

Video you posted have no drivetrain, no chain connected to the mid drive, no propelling of rear wheel, do you ride your ebike like that?

Hub-drive with fat tire are "crazy heavy" compared to what? at what price?

how many mid-drive ebikes that are not "crazy heavy" can you find under $2K?

Fact is, without an working drivetrain,

fooferdoggie 

the video is showing how little resistance is in thew motor its self. you claimed mid drives have a huge amount of drag. the bike has no more drag minus that tiny bit any regular bike with similar sized wheels. How else would you test the drag of a motor? the UK is full of throttle less hub drives.
sub 2k hub drive bikes tend to have fat tires and are 65# or over. there are few mid drivers under 2000.00 they sit cut more money.

cat0020

Here are my exact words:
Regardless of throttle usage or not, the drivetrain is required to have mid-drive motor transfer power to the rear wheel,
but no so for the hub motor ebikes.
If your drivetrain is dirty or lack lubrication, not only does it cause more wear, it also robs power from your mid-drive motor; but not so much with a hub-motor ebike.

Sure mid-drive ebike can be ridden without a battery, but with extra resistance of the motor & friction in drivetrain.

Nowhere did I say anything about "huge amount of power drag".

Exactly how many sub $2k hub drive ebikes have you weigh? how much do they each weigh?

Go ahead and name them.
How many of them come with a Bosch motor that have low drag?

fooferdoggie 

drag on the drivetrain on a mid drive is like any other bike. thats just a pointless argument. the drag on a hub drive bike has actually more because if nothing else the rear wheel is far more massive. if you have to pedal either one without power the hub drive will be harder to do so. I have looked at the weight of many hub drive bikes 65# is pretty average but now you are seeing even larger batters or two batteries so they are getting to be 75# or even more. even for a 20" wheel bike. Let's see lectric rad hey bike I could go on all day long.

cat0020

Pointless argument yet you keep repeating it.

Learn to read what I wrote in my previous posts.

Name the specific ebikes that you've used and weighed and specify the weigh on each of them.
You could go on all day long but fail to give any details.
How many mid drive ebikes under $2K have Bosch motors with low drag?

Moe Zhoost

Well, It seems that you've responded to others with similar opinions, so I'll just respond briefly to what you've quoted me on.
I don't own any, though I've worked on quite a few for friends and on those donated to our local co-op. Of those that required a wheel disassembly, at least half of them had crunchy bearings. This would not likely be apparent to a rider, but it is a demonstration that it happens. It's not a big deal for most bikes with sealed bearings, but with a hub motor it will require much more labor than is economically viable. These are throw-away wheels. Were getting more and more e-bikes donated to our co-op, mostly because the cost of replacing a battery or fixing another component is not worth it to the owner. Many have developed cracks in the wheel spoke holes.

Yep, I did bring it up, and I feel bad that it resulted in your hijacking the OP's post.

.

I've not found that my mid-drive bike wears any drivetrain component more quickly than my other bikes. My sense is that this wear argument is a 'sales' pitch. In any case, all bikes require maintenance.



Yep, you're right that only direct drive hub motors are good for generating electricity. My initial comment was not aimed at recovering energy while riding. It was related to repurposing a hub after removing from a wheel. Configure it as a windmill or waterwheel or similar and you can generate 3 phase AC power. You'd need to run the current through a full-bridge rectifier to convert to single phase DC to charge batteries. Repurposing these hubs is a lot better than them ending up in landfills.

Feel free to continue your crusade against mid-drive systems, though perhaps you should open a new thread. I'll not be responding to further posts in this thread. Good luck to you, mate.

cat0020

I've no crusade against mid-drive ebikes,
all I mentioned are true and not opinions.

1. Generally, mid-drive ebikes are more expensive than hub-motor ebikes.

2. Mid-drive ebikes require a working drivetrain to operate vs hub-drive ebikes can be ridden without a working drivetrain.

3. Mid-drive ebikes cause more stress on drivetrain than hub-drive ebikes.

4. Mid-drive ebike require more frequent maintenance on drivetrain than hub-drive ebikes for optimal performance and longevity.

5. Weight distribution of hub-motor vs mid-drive ebikes are exaggerated when majority of ebike users are not competing in sanctioned cycling events that require weight distribution to be a determining factor for performance.



How many mid-drive ebikes have you owned? how many miles have you ridden on it?
Do you have similar riding experience on a hub-drive ebike to draw decent comaparison between the two?


Repurposing a hub motor for electric generation, is that another hijack?
Of course you will not respond further, since you cannot provide evidence or data to support your opinion; without them, opinions are often invalid.

Back to the topic of thread: hub-drive ebikes can offer hill climbing performance that can match mid-drive ebike.
Whether a rider is using throttle or PAS to climb, knowing how to shift and using the proper gearing available on a bike is what allows a bike to climb over a hill.