My Thoughts on Mid Drive..Hub Drive and Throttle

[erider_61]

Just a first time owners 2 cents worth. Last Sat as I arrived to work my left pedal fell off. Thinking no big deal as they had loosened a few times previously and I had always been able to tighten them. Well after 1,300 km this time I realized the aluminum crank was stripped.

If not for the rear hub motor and throttle I would have been dead in the water. Was able to zip over to Canadian Tire and buy some JB Weld epoxy and then throttle home and make a temporary repair. That would not have been an option with mid drive and no throttle.

Ordered new cranks and pedals and will look into if this might be covered by warranty, although I am doubting it even though I did check the issue of pedals loosening previously. For me a hub drive and throttle certainly saved the day....

 

[rich c]

"Loosened a few times previously" may have been an indicator of preventive maintenance required. Not sure a throttle is a good reason to not follow up on drivetrain issues.

 

[erider_61]

"Loosened a few times previously" may have been an indicator of preventive maintenance required. Not sure a throttle is a good reason to not follow up on drivetrain issues.

Well I was checking them weekly, including rear axle nuts and tire pressure, etc. Just like I do with my Raleigh road bike which has been ridden 20 years & thousands of km with no issues other than general maintenance. I do find that I ride at a much higher cadence on my ebike, almost always in PAL 9, so this may have contributed to the pedal issue. I JB Welded the right pedal as well last night and most likely will do the same with new pedals & cranks when I get them. Would that be "Preventative Maintenance"...lol

 

[Alaskan]

I had this happen to my first ebike and it was my fault due to two errors. I replaced my pedals without using grease or never seize and I did not check on the proper torque for securing the pedal to the crank. I had a pedal wrench which was about a foot long and gave it what I thought was a solid tightening. I am an above average sized person with commensurate strength. I was in the process of trying various pedals. When I replaced them the second time, it did not go back on smoothly and ended up stripping on the very next ride. Some suggest that just snug is sufficient. Clearly if they are loose enough to work back and forth they will damage the threads. We are dealing with a steel bolt in a threaded aluminum crank so proper installation is critical. That means grease and a torque wrench.

One can read many opinions on how tight to make pedals from just barely because thread direction allows your feet to tighten them just right to as hard as you can using an 8mm hex wrench. As hard as you can can be different from as hard as I can. This thread on the topic has many opinions and most of them stink: https://www.bikeforums.net/bicycle-mechanics/268330-installing-pedals-how-much-torque.html

Park Tool has a page of suggested torque values for every bike part that any home mechanic should use. I do now https://www.parktool.com/blog/repair-help/torque-specifications-and-concepts

 

[6zfshdb]

If not for the rear hub motor and throttle I would have been dead in the water. Was able to throttle home and make a temporary repair. That would not have been an option with mid drive and no throttle.

I ride in some pretty remote places and this was the main reason I chose a hub drive ebike. My aging joints are also prone to injury which could impede my ability to pedal. I know I sacrificed some hill climbing performance with a hub motor but to me, the trade off was worth it.

There are many reasons for choosing a particular type of drive. Each individual rider needs to give some thought as to the one that will work best for their personal needs and riding style.

 

[ElevenAD]

Just a first time owners 2 cents worth. Last Sat as I arrived to work my left pedal fell off. Thinking no big deal as they had loosened a few times previously and I had always been able to tighten them. Well after 1,300 km this time I realized the aluminum crank was stripped.

If not for the rear hub motor and throttle I would have been dead in the water. Was able to zip over to Canadian Tire and buy some JB Weld epoxy and then throttle home and make a temporary repair. That would not have been an option with mid drive and no throttle.

Ordered new cranks and pedals and will look into if this might be covered by warranty, although I am doubting it even though I did check the issue of pedals loosening previously. For me a hub drive and throttle certainly saved the day....

i alternate between Hub and Mid drive every other day and both really do have advantages, i dont do a ton of offroad so my ideal set up is High Power Hub with throttle allday! i also have the same bike as you, great bike!

 

[Marci jo]

I had this happen to my first ebike and it was my fault due to two errors. I replaced my pedals without using grease or never seize and I did not check on the proper torque for securing the pedal to the crank. I had a pedal wrench which was about a foot long and gave it what I thought was a solid tightening. I am an above average sized person with commensurate strength. I was in the process of trying various pedals. When I replaced them the second time, it did not go back on smoothly and ended up stripping on the very next ride. Some suggest that just snug is sufficient. Clearly if they are loose enough to work back and forth they will damage the threads. We are dealing with a steel bolt in a threaded aluminum crank so proper installation is critical. That means grease and a torque wrench.

One can read many opinions on how tight to make pedals from just barely because thread direction allows your feet to tighten them just right to as hard as you can using an 8mm hex wrench. As hard as you can can be different from as hard as I can. This thread on the topic has many opinions and most of them stink: https://www.bikeforums.net/bicycle-mechanics/268330-installing-pedals-how-much-torque.html

Alaskan,
I can so relate to your experience with pedal replacement. Some years ago on a new nonpowered bike, I switch the pedals and inadvertently cross treaded one pedal. Of course it was the odd reverse-threaded left pedal and within 5 miles it loosened and fell off. Had to call hubby for a ride. Fortunately only the first turn or two on the crank was destroyed, otherwise I would have had to replace crank (and maybe axel??)
Now I'm fairly paranoid of repeating the experience so I simply bring whatever bike into my lbs and they switch out pedals for free. Have a great relationship with them but I think in secret they chuckle at me.

 

[Alaskan]

Alaskan,
I can so relate to your experience with pedal replacement. Some years ago on a new nonpowered bike, I switch the pedals and inadvertently cross treaded one pedal. Of course it was the odd reverse-threaded left pedal and within 5 miles it loosened and fell off. Had to call hubby for a ride. Fortunately only the first turn or two on the crank was destroyed, otherwise I would have had to replace crank (and maybe axel??)
Now I'm fairly paranoid of repeating the experience so I simply bring whatever bike into my lbs and they switch out pedals for free. Have a great relationship with them but I think in secret they chuckle at me.

The real key is learning to chuckle at yourself

 

[rich c]

Well I was checking them weekly, including rear axle nuts and tire pressure, etc. Just like I do with my Raleigh road bike which has been ridden 20 years & thousands of km with no issues other than general maintenance. I do find that I ride at a much higher cadence on my ebike, almost always in PAL 9, so this may have contributed to the pedal issue. I JB Welded the right pedal as well last night and most likely will do the same with new pedals & cranks when I get them. Would that be "Preventative Maintenance"...lol

I'm still convinced that crank material alloy, and contact area between the pedal shaft shoulder and the crank, is more important that proper torque. The design of having a pedal cantilevered off a threaded shaft, with very little shoulder area contacting the crank, sets the design up for failure. The design creates some very high load numbers that will eventually overload the threads, bend them, and lead to thread failure. I'd suggest that cadence has very little to do with the failure compared to force on the pedal itself. You might want to read the result of JB weld in this rider test. https://forums.bikeride.com/thread-2840.html

 

[J.R.]

Just a first time owners 2 cents worth. Last Sat as I arrived to work my left pedal fell off. Thinking no big deal as they had loosened a few times previously and I had always been able to tighten them. Well after 1,300 km this time I realized the aluminum crank was stripped.

If not for the rear hub motor and throttle I would have been dead in the water. Was able to zip over to Canadian Tire and buy some JB Weld epoxy and then throttle home and make a temporary repair. That would not have been an option with mid drive and no throttle.

Ordered new cranks and pedals and will look into if this might be covered by warranty, although I am doubting it even though I did check the issue of pedals loosening previously. For me a hub drive and throttle certainly saved the day....

I can see why the throttle saved you from walking in this circumstance. There are mid drives with throttles though, so the drive really doesn't come into play here.

 

[ruffruff]

This is a big discussion right now with hunting on Ebikes.
Being 5 miles back on a logging road and have something go on your mid-drive would suck!

 

[The duke]

Ok, challenge. I've heard hubbies rave about how their rear hub motor saved them....broken chain, broken crank, broken pedal. I've heard how the throttle got them home when they were at death's door.

Is there an example of something amazing and life saving that a mid drive motor can do that a hub can't? As a middie, I'd like something to brag about too

 

[Ken M]

I'm still convinced that crank material alloy, and contact area between the pedal shaft shoulder and the crank, is more important that proper torque. The design of having a pedal cantilevered off a threaded shaft, with very little shoulder area contacting the crank, sets the design up for failure. The design creates some very high load numbers that will eventually overload the threads, bend them, and lead to thread failure. I'd suggest that cadence has very little to do with the failure compared to force on the pedal itself. You might want to read the result of JB weld in this rider test. https://forums.bikeride.com/thread-2840.html

I believe this is very true and in some ways intentional by the industry. In reality all pedals should come with nice shoulders and washers that all the axial preload to help distribute the cantilever loads which are very significant with many riders. I always had my pedals tights and had a crach thread fail so now I always make sure to have a washer. There are some good aluminum cranks with steel threaded inserts that would likely never fail.

 

[ebikemom]

Is there an example of something amazing and life saving that a mid drive motor can do that a hub can't? As a middie, I'd like something to brag about too

NOTE: Everything written below is in jest!

You can support bike techs with all you pay in maintenance if you are a high-mileage, high-speed rider of a mid-drive bike! My local bike tech definitely is feeling that love! Whenever I am there and he has a mid-drive on the rack he tells me that the bike's owner has spent lots of $$ on maintenance. Meanwhile, for me he does ... tires and lots of freebie adjustments.

You could get a T-shirt:

"Support your local bike tech... buy a mid-drive ebike!", cutely illustrated with a mid-drive bike up on a repair rack.

 

[indianajo]

My $75 at the flea market, probably $160 new Pacific Quantum MTB had trouble with the pedal coming unscrewed and wallowing the hole out. "Solved" the problem by finding an identical bike at Salvation Army resale shop for $12. The crank arms on those bikes was plastic, and wouldn't come off with various pullers. I got the feeling that perhaps those bikes were not intended to last 6000 miles, which was about 3 years use.
My $1800 Yubabikes bodaboda, shown left, has had no such problem in ~5000 miles. The pedal did start squeaking around mile 4000, so I had to take them out to let oil ooze down into the rotating surface. They went back on fine and ~1000 miles later still no problem. I did use anti-sieze when I put them back in, because no bike I have owned would let me unscrew the pedals before.
Oh, the yubabike pedals are 15 mm OD. Weird size, larger than 9/16" USA 60's standard and 13 mm on the Pacific Quantum. I looked for 15 mm replacements at modernbike.com and didn't find any. Both bike parts agencies are totally devoid of dimensions on nearly anything they sell. Niagaracycle sent me "14 mm" nuts where no dimension on the nut, not even the root diameter of the threads, was 14 mm. They are now "thebikeshopstore.com" . They managed to send me axle nuts once, 3/8x26 tpi, but the next time they sent me some random hexagon shaped trash. Ended up making them with a tap from victornet.com

 

[tomjasz]

It is all subject to failure and breaking. Kinda like life. For some reason this made me think of the movie with George Burns and two other old fellas. They robbed a bank. At one point they’re sitting on the same bench lamenting the fact that they had come full circle, back to needing diapers. There’s no escape. s*it happens.,

 

[Feliz]

It is all subject to failure and breaking. Kinda like life. For some reason this made me think of the movie with George Burns and two other old fellas. They robbed a bank. At one point they’re sitting on the same bench lamenting the fact that they had come full circle, back to needing diapers. There’s no escape. s*it happens.,

The name of the movie was "going in style".

 

[The duke]

NOTE: Everything written below is in jest!

You can support bike techs with all you pay in maintenance if you are a high-mileage, high-speed rider of a mid-drive bike! My local bike tech definitely is feeling that love! Whenever I am there and he has a mid-drive on the rack he tells me that the bike's owner has spent lots of $$ on maintenance. Meanwhile, for me he does ... tires and lots of freebie adjustments.

You could get a T-shirt:

"Support your local bike tech... buy a mid-drive ebike!", cutely illustrated with a mid-drive bike up on a repair rack.

As someone who knows nothing about ebikes, I am concerned to know just how much of your post was in jest

 

[Mr. Coffee]

Ok, challenge. I've heard hubbies rave about how their rear hub motor saved them....broken chain, broken crank, broken pedal. I've heard how the throttle got them home when they were at death's door.

Is there an example of something amazing and life saving that a mid drive motor can do that a hub can't? As a middie, I'd like something to brag about too

I can think of two things.

The strongest argument is that mid-drives, all other things being equal, can climb steeper hills.

The somewhat less strong argument is that a mid-drive uses fewer watt-hours per mile, so you can go further on a given battery charge.

 

[The duke]

I can think of two things.

The strongest argument is that mid-drives, all other things being equal, can climb steeper hills.

The somewhat less strong argument is that a mid-drive uses fewer watt-hours per mile, so you can go further on a given battery charge.

That wont get me a spot between Thor and Captain America on the Avengers, but I'll take it