Are mid drives just naturally less zippy than hub motors?

[rjdavis4]

It's been a couple days since I looked at this thread and wow there are some great responses here. Loving all this information from you folks.

Yeah the first thing I noticed when I went to mid drives from geared hubs was the geared hub was a lot faster off the line, considering that you had to start from a lower gear to get the bike up and running. Starting from a lower gear, you lost time vs. the geared hub by the blips in acceleration that comes from rowing thru the gears. The mid drive doesn't become a performance leader until you mix hills in. Thats where it wins both for initial and sustained speed as well as longevity (mid drive will not fry/strip its poor little nylon internals).

On flat ground, nothing touches the acceleration on my 2wd geared hub commuter. That thing will make you giggle, and the way its geared, you still get a hard workout. But it lacks versatility which is the Achilles heel of hub motors. A mid will get you thru anything, everywhere.

This is another post that aligns pretty close with my experience. I think acceleration off the line is a big part of what I consider zippy and I just get that feeling more with the hub drives I've ridden than the mid drives.

Still I do wonder a lot about how much of a factor the controller programming is. I have yet to own a bike where I had access to re-program the motor response/output. I feel like I would really enjoy tinkering around with the programming to dial in the ride feeling I am looking for.

 

[AHicks]

Still I do wonder a lot about how much of a factor the controller programming is. I have yet to own a bike where I had access to re-program the motor response/output. I feel like I would really enjoy tinkering around with the programming to dial in the ride feeling I am looking for.

That ability my friend, will spoil you forever. It will raise your standards so high very few production controllers will even come close - especially OEM hub controllers.....

 

[m@Robertson]

Still I do wonder a lot about how much of a factor the controller programming is. I have yet to own a bike where I had access to re-program the motor response/output. I feel like I would really enjoy tinkering around with the programming to dial in the ride feeling I am looking for.

To restate a little differently, the weakness of the hub motor is its strength in this one narrow segment: No transmission. A hub motor is just stab'n'steer from zero on up. Great for a drag strip kind of application and ideal for flat ground. Its also the easiest to ride for a newcomer because no brain cells need engagement to shift to higher gears, or to remember to shift down *before* you come to a stop. The whole drivetrain is irrelevant since the motor powers thru the axle. These things can be liabilities in other areas but if you are looking for fun off the line a geared hub (or a really big DD hub like a QSv3 with a hi-po battery) is the ticket. Arguably, this puts you closer to light electric vehicle territory than it does to electric bicycle, but I don't mind taking another car off the street one bit.

That ability my friend, will spoil you forever. It will raise your standards so high very few production controllers will even come close - especially OEM hub controllers.....

^^^ this x 100

 

[m@Robertson]

I'm building a triple hub with mid drive , just because. This will end all debates. 2 hub motors up front , one in the rear and a mid drive.

I have seen a Rungu in person and they are truly gigantic. Everything is scaled up. They didn't just add another wheel.

As for mid+hub... its been done with great success. Can go thru things a mid or even the most powerful rear hub can't even think of. In deep, dry beach sand, the front motor keeps the front wheel from its natural tendency to plow/submerge, and when things get ugly it helps pull you thru a drift you are climbing over. Extends a ride - that can't go more than 30 yds before the rider gives up - to as many miles as your battery will hold up. You never want to run out of juice which is why I have a charger on the front rack. The bathroom at the park destination at the end of this ride has a power plug I use to let me get all the way back home.

That Rungu truly does have dramatically improved awful-terrain capability. But what they need a second front wheel for can be accomplished by adding a motor to the existing wheel. Pretty sure if you tried motorizing both of the front wheels you'd run into a synchronization issue. However... thats what people said about 2wd ebikes and that turned out to be nonsense, so maybe it can be done - by someone else

 

[PedalUma]

I too have pondered a totally integrated system. The thing is, keeping things separate has the advantage of maintaining components separately. It is simple and not proprietary to install a fresh cassette.

 

[Catalyzt]

The video seemed to not tell the whole story, showed a bias toward mid drives.
If you are buying an E bike, not building, and it’s a road bike/ not a mtn E bike, then it’s a much different comparison.

I disagree with a couple important points:
- Mids are more reliable … can break chains but hubs loosen spikes. Quality hub bikes engineer the rear wheel / spokes for their intended use.
I know of many hub drives with 50.000 miles but not mids.
And don’t get me started on chain life where mid drives add to chain wear vs hub motors which lessen the drivetrain load and extend chain/ gear life.

- His saying mids feel more natural is imo clearly not true if you look at a well engineered hub bike with dialed in cadence and torque sensing.
I ride a hub drive mainly because I never found a mid that felt as natural!

I also value the silent hub motor aspect vs mids.

His comparison had some valid points but some stereotypes that tainted it.

A lot depends on your usage and what you value in your E bike.
I do city riding and want a smooth and quiet and reliable and efficient 28 mph bike.

P.S. The German TQ mid does interest me a lot with its design and crank concentric motor.
If one can live with only 250 watts….
Looks like a winner in the lightweight E road bike niche.

Those Trek Fuels are nice-- but expensive. 44 pounds and 50nm sounds almost right. 60nm and 41 pounds would be outstanding!

For the moment, I'm fine with 46 pounds and 40nm, but on 15%+ hills, it's still a LITTLE intimidating after a long work day... when I'm this long in the tooth!

 

[AHicks]

It's been a couple days since I looked at this thread and wow there are some great responses here. Loving all this information from you folks.



This is another post that aligns pretty close with my experience. I think acceleration off the line is a big part of what I consider zippy and I just get that feeling more with the hub drives I've ridden than the mid drives.

Still I do wonder a lot about how much of a factor the controller programming is. I have yet to own a bike where I had access to re-program the motor response/output. I feel like I would really enjoy tinkering around with the programming to dial in the ride feeling I am looking for.

On further thought, I wanted to add the fact that not only am I totally spoiled with the ability to set up many of the controller attributes to my own tastes/riding habits, I now purchase hub driven bikes with little thought to what the OEM controller is like. Why? Because I plan on adding an aftermarket KT controller and display as part of setting up a new bike. I'll ride the OEM controller for a bit to see if anything can be done with it, but I'm already pretty sure the KT conversion is a done deal. For me, the KT conversion is just like setting up the bike for an upright riding position and adding a suspension seat post - something I plan on doing before the bike is ridden much.

These KT conversions, that can be purchased for 100. or so, are an example of what CAN be done with a controller. In comparison, most OEM controllers, because of their locked down features, or lack of features (in programming), could be considered a sin on the buying public. They get away with cheap controllers ONLY through the ignorance of the fact there are WAY better available and there are so many buying these as a first e-bike. My hope is that as the industry matures, buyers become more aware with higher expectations, the OEM controller features will advance quickly as the technology is there right now, today. KT conversions are proof of that fact....

One last thought. For those that might consider this KT conversion, which is admittedly not for the faint of heart (e.g. there's NO directions), an example of what CAN be done. We purchased a 2020 Espin Flow bike (plain vanilla 27.5" 55 lb step through) for the wife on a Black Friday sale cheap (1399. maybe?). As expected, the controller was junk, but the rest of the bike, with it's 500w Bafang motor, we fell in love with. A KT conversion was done (KT-22a w/waterproof connectors), upright riding position mods done, seat and seat post, and we had a bike that I would compare favorably to any other geared hub bike available - for less than 2000 total. So we bought 2 more Espins (yes, not on sale, so both were a little more money). Another Flow, and a Sport which is the step over/diamond type version of the Flow. They were modified identically as the first bike.

The Sport turned out to be a fantastic bike, one of my favorites (and definitely the lightest of all of them). At just a hair over 2K with all the mods, it's a full size 55lb geared hub bike that not only handles well, but features 1000w of "zippy" on demand. The little 500w motor is very capable of breathing fire, providing some very lively performance for getting across a street in a hurry, climbing a short hill, or catching up with a riding buddy. Downside, if there is one, is it's only going to provide that kind of performance very short term. Long hills, or extended "speed runs" (to answer the how fast will it go question) are going to cause it to build heat quickly, to the point something is going to melt down on you. YOU have to have the maturity to prevent abuse. It WILL smoke if abused. It's 14ah battery is also good for 30+ mile range pretty easily when ridden conservatively using PAS 1.

 

[m@Robertson]

... Because I plan on adding an aftermarket KT controller and display as part of setting up a new bike.

Ditto. The last time I bought a full hub kit it was because I thought the already-built wheel in the kit was worth the price paid for it all, and I couldn't get just the wheel. I have looked into the Grin hub motors but cannot justify leaving behind the low-cost, easy-job, guaranteed-results utility of the KT stuff.

The very last part needed for my current project is getting ordered today: The KT-LCD3U display. Waiting on frame/fork scheduled to arrive some time in November.

 

[Jason Knight]

So you don't ghost pedal.

Which is exactly what I was talking about preventing, so I'm not sure what you're trying to say. Rather than neutering the output by turning the controller settings down, up the gear ratio. What part of that did you fail to understand?

Adjustments to pedal assist do not necessarily affect overall controller output.

Then what exactly do you think it's doing, blowing rainbow unicorn farts?

On a Bafang mid drive you still have the throttle available at full blast if you desire full power.

Which is all fine and dandy if talking about mid-drives. Which I was not since I was talking about my Aventure... which has no settings for what the assist levels even do and is a hub drive.

The Sondors bikes have assist-only settings as well on their hub motor bikes. KT controllers not so much but they do have an assist increment that either dials down or dials up the difference between the assist levels.

Which again is fine and dandy for those bikes. But as I said: "but for a lot of us that's not even an option..." since not all controllers even let you do that! And if you're dialing down the highest assist, you're dialing down the power of the highest assist! Hurr-durrz!

All I was saying is that for many bikes -- like my Aventon Aventure -- changing the gear ratio is the only solution, and for many hub motor bikes it's the better solution than turning down the power. Which is what adjusting the assist settings would inherently do. Otherwise what the blue blazes are you turning down?

 

[Jason Knight]

I think all of the mid drives carry the torque sensor inside. I KNOW the Bafang's do.

They'd have to, where else are they going to put it. As I said though, "hub motors" seem to universally have been cadence sensors, though I'm starting to see torque sensors (aventon's level 2) at the pedals with hub motors finally become a thing.

It's just really weird we don't just see larger diameter hubs to fit it back there. I'd think if you wanted to measure torque the most accurate place to do so would be after the pedal drive-train, not before it so you know how much ACTUAL torque is trying to be translated to the ground.

Regarding the planetary trannies, have you checked out the NuVinci/Enviolo?

CVT's (which technically are not planetary) are an interesting tech, but heavy. I've always wanted to play with one because its somehow simultaneously simpler and complex. I've heard a lot of people talk about how they "slip" or can't handle as much load, and that's something else setting off my BS alarm since there are MBT's (main battle tanks) like the M1 Abrams that use them in combination with CAT (clutch as throttle) and turbine engines.

Bonus if going that route is to scrap the chain and go belt driven.

Another bit o' kit I've not dealt with that I'd love to. When/if I have money again I might start tinkering with a DIY build assuming I'm not too decrepit to do so by then.

It's like the warranty ran out when I hit fifty years old.

 

[SC00CHB00CH]

So I sold my mid drive and the gentlemen who bought it was doing a test drive was pulling up a steep hill in the highest gear. I said you need to understand how mid-drives work. He didn't seem to understand the concept of starting in 1st gear at a red light and using lower gears for hills.
Then he started to shift all gears from 11 to 32 while standing still on the bike. I warned him not to shift gears while the bike is stationary from the 11 teeth cog to the largest 32 teeth. Imagine if he had throttled 120nm of torque like that? The gears would have done an extreme jump from 11 to 32 under torque.

Then after some learning curves I convinced him to try a top speed run on a long flat road near my house he then proceeded to get to about 36mph/58kph in top gear and complained his legs were just ghost pedaling at 36mph/58kph and how he wanted to change the cassette. I told him for a natural human to pedal that fast and 'feel the pedals' you'd need to a front chain ring the size of a *metal garbage can lid, since the front wheels are only 20inches. The bike already has a 52T front ring a 11teeth rear at it's smallest. He could try for a 10 or 9 rear but then you introduce a lot of torque to just 9 or 10 teeth . It took me many hours to get the chain ring dialed in-just right for the 11 tooth so there was zero torque slippage at full throttle in all gears. 36mph/58kph on a 20 inch folding bike is plenty fast enough IMO.

He purchased the bike off EBAY from me and I was close to refusing to let him take the bike and send him a refund. I told him if he feels uncomfortable with the bike , full refund right now off ebay. I'll keep the bike. But he said no he really liked the bike "it's super fast" he said and was starting to understand basically he has a manual transmission car.

After following up on phone with him I suggested to install a gear shift sensor and possibly consider converting it to a IGH. He said he's looking into getting an IGH from his bike shop. I said for his needs that would be the best option. I was planning on adding a ROHLOFF to it myself but after dialing in the chainring which had no slippage I really didn't need it but WANTED it.

His last bike was/is a pedego hub motor bike that his wife uses.



*exaggeration for emphasis

 

[m@Robertson]

Which is exactly what I was talking about preventing, so I'm not sure what you're trying to say. Rather than neutering the output by turning the controller settings down, up the gear ratio. What part of that did you fail to understand?

Then what exactly do you think it's doing, blowing rainbow unicorn farts?

Which is all fine and dandy if talking about mid-drives. Which I was not since I was talking about my Aventure... which has no settings for what the assist levels even do and is a hub drive.

Which again is fine and dandy for those bikes. But as I said: "but for a lot of us that's not even an option..." since not all controllers even let you do that! And if you're dialing down the highest assist, you're dialing down the power of the highest assist! Hurr-durrz!

All I was saying is that for many bikes -- like my Aventon Aventure -- changing the gear ratio is the only solution, and for many hub motor bikes it's the better solution than turning down the power. Which is what adjusting the assist settings would inherently do. Otherwise what the blue blazes are you turning down?

The concept of listening and learning is anathema to you and I didn't expect you to make any attempt to either self-reflect or understand. Once again, regular as clockwork, as you just demonstrated this with your trademarked obnoxiousness dialed up to 11.

Have fun ranting. It is, after all, what you are able to successfully do (i.e. the Gish Gallop).

 

[tomjasz]

Then what exactly do you think it's doing, blowing rainbow unicorn farts?

Oh “Richard” always the insults

 

[tomjasz]

It's just really weird we don't just see

You and the turd in your pocket? Lots of us have the experience you are clueless about. Were you picked on for being a small guy and the internet gives you the opportunity to inflate your presence? FFS fella.,,

 

[PedalUma]

I am just not engaging with the stuff here that is over-the-top.

 

[JRA]

There is an old saying where I grew up in VT that you can tell that someone is from NH but you can't tell them much.

 

[Djangodog]

There is an old saying where I grew up on VT that you can tell that someone is from NH but you can't tell them much.

Hey, I resemble that remark!!! OK, fair enough.

I think that Mr, Knight lives in NH, but is not from NH. To be honest, I am from elsewhere myself.

 

[Rexlion]

My .02 from riding both types for a number of years is that it is very dependent on terrain. I find that my hub motor drop bar bike is much more fun on the road, even with hills involved. I put together a flat bar road bike with the same size wheels, 700c x 40c, and a torque sensing mid drive, TSDZ2 which arguably isn't as sophisticated as the major brands but is more powerful overall. I had at the time the same motor system on my eMTB so was very familiar with how to get the most performance out of it but couldn't get it to feel like my hub bike so I put some other wider rims and tires on it and although it is fully ridged my son who lives in a city loves it.

The feeling of gliding along with just the right amount of pedal pressure that you want pretty much demands a torque assist system of some type and the Juiced seems to have hit the sweet spot with theirs? However how I get that feeling is via no PAS. How I work it is to have a conventional derailleur system, but I do use a Schlumpf High Speed Drive to get the higher gear ratios that will match up with the motor at speed to get the effect you talk about. Because there is no strain on the chain other than what I have been used to for years and the constant momentum provided by my hub, DD Grin All Axle front motor btw, with only a throttle to control the watt output of the motor and the ability to set it on "cruise control" it even helps to make you more aware of the dead spots in your spin and gives you something to work on while riding. I liken the effect to having a row boat with a trolling motor if that makes any sense.

Peoples fear of front drive hubs, direct drive hubs and throttles doesn't make my method at all popular but after thousands of miles from sea level to 9000' ele it works for me. I ride mainly on gravel and secondary paved roads with it but have diced up a little mellow single track as well. But for off road adventures of single track, beach/sand trails and the chunkier gravel logging roads around me a FS M620 bike is my go to rig and gets the most use frankly. But as a long time bike addict I am used to having a few bikes around.

One thing I will say though is that it takes me a few miles to get back into the way the drop bar bike works most efficiently whereas the mid drive bike doesn't.

I'm curious to know how one sets up a Schlumpf drive when there is a torque or cadence sensor involved with the crank. Any special challenges or limitations?

 

[Rexlion]

Regarding zip or the lack thereof, on throttle only my R1U LMTD feels rather slow off the line (whereas pedaling with the torque sensor will accelerate better) but once it reaches 5-6 mph I start to feel the torque on throttle. Seems like the MXUS geared hub needs to build up a bit of speed before it really gets going all by itself.

I have left my controller on 3 PAS speeds (0-3 actually) and the only change was I bumped up the PAS 1 from 33% to 40%. PAS 2 is 66% and PAS 3 is 99%. Works well for me.

 

[SC00CHB00CH]

Regarding zip or the lack thereof, on throttle only my R1U LMTD feels rather slow off the line (whereas pedaling with the torque sensor will accelerate better) but once it reaches 5-6 mph I start to feel the torque on throttle. Seems like the MXUS geared hub needs to build up a bit of speed before it really gets going all by itself.

I have left my controller on 3 PAS speeds (0-3 actually) and the only change was I bumped up the PAS 1 from 33% to 40%. PAS 2 is 66% and PAS 3 is 99%. Works well for me.

If I hit the throttle 1/2 way on my mid drive off the line the front tire will wheelie off the ground there is so much torque and it will buck the rider off like a horse. I added some weight to the frame using a larger shark battery pack. This helped with the torque pull and made the drivability off the line a lot less scary. This is with a 52T front chainring. I had a 28T I used that made the bike feel like a F-1 car. The top speed with the 28t was only around 23/25mph but the acceleration was bone breaking fast.