2014 E3 Path+ Issues/Conerns

[Todd Pepin]

Hi. I'm new here and hope someone can help. I just bought the E3 Path+. It's being used as a commuter for a 22 mile round trip. So far it's been great. Better than I expected, especially on a couple of the hills I have to climb. I've owned the bike for just about two weeks now and have a couple of issues cropping up.

1. I am experiencing death wobble. When the bike coasts up to 30 mph it's fine. Go over that and it begins to become unstable. Several people thinks it's an out of balance wheel. A local bike shop thinks it's a design problem. I haven't seen anything anywhere about this issue on this bike.

2. The rear wheel seems to have some kind of thump or wobble of it's own. If you lift the rear wheel off the ground and trigger the throttle you can feel the a shimmy in the back end. Again the shop could not find an out of balance wheel. What they did find was that the tire wasn't mounted on the rim correctly. They proceeded to fix that, but it didn't solve the wobble. I have a suspicion that this rear wobble may be contributing to the front wobble.

3. Yesterday (Saturday August 2, 2014) traveling close to 30 mph, touching the brakes to keep it under that and avoid wobble, the rear hub suddenly locked up and dragged for about 10 or 15 feet and released. I was not touching any brakes when this happed. I pulled over and checked to see if anything was wet, as the road was damp but not soaked. The electronics, battery and motor had no liquid on them that was apparent.

It should be noted that the death wobble was noticed from day one. It took a couple of rides to find the rear wobble. I find the bike shop's assessment of a design flaw to not be correct. If there was such a problem, it would have been found by reviewers and would have scored heavily against the bike. I've had many traditional bikes since I was old enough to ride. New bikes, hand-me-downs, dump fixer-uppers, and hacks. Not one of them ever had death wobble. Hoping it some kind of adjustment.

On a positive ending note, It's still the most fun I've had on bike, ever. It get's a lot of looks, turns heads, and it get's a lot of attention at work. Best of all I don't have to wear myself out on big nasty hills anymore, just pedal comfortably over them. Awesome!

Todd

 

[JoePah]

Sounds like loose magnets, which is a known problem discussed elsewhere on this site: http://electricbikereview.com/community/threads/izip-e3-path-plus-trouble.273/

 

[ChrisD_]

I can confirm that my E3 Path+ will wobble when I ride no-hands above ~18 mph. I'll have to try it this week to see if I pin down the speed a little better. "Death" wobble, well maybe if I didn't damp it by grabbing the bars!

 

[calvin]

Read: http://en.wikipedia.org/wiki/Speed_wobble and: https://www.sheldonbrown.com/brandt/shimmy.html Small imperfections in the tire, wheel, steering mechanism can add up at higher speeds. I would change the front tire first. Always try the cheapest easiest fix first before going on to more exotic repairs. Consider that the lack of mass, in the front wheel probably accentuates these imperfections, so if we want high speeds 25+ lets get a motorcycle, electric or not. This is a dangerous condition. A steering damping device may help:

.

Keep us posted. I am having a deja vu experience, haven't we already covered this before?

 

[Todd Pepin]

Read: http://en.wikipedia.org/wiki/Speed_wobble and: http://sheldonbrown.com/brandt/shimmy.html. Small imperfections in the tire, wheel, steering mechanism can add up at higher speeds. I would change the front tire first. Always try the cheapest easiest fix first before going on to more exotic repairs. Consider that the lack of mass, in the front wheel probably accentuates these imperfections, so if we want high speeds 25+ lets get a motorcycle, electric or not. A steering dampener may help:

.

Keep us posted.

The speed came from a natural coast down a big hill in my commute. Tapping the brake keeping the bike under 25 is keeping it under control. I never experienced this on any other bike I ever rode. Is it possible the issue with the rear wheel could be contributing?

 

[calvin]

No, probably not, unless that rear wheel is out of alignment: again read: https://www.sheldonbrown.com/brandt/shimmy.html

However, there is a mention of loose rear spokes here in the glossary under "shimmy": https://www.sheldonbrown.com/gloss_sa-o.html

There is another rather depressing (non-fixable) take on the death wobble or shimmy: http://davesbikeblog.blogspot.com/2005/11/high-speed-shimmy.html

With a follow up here: http://davesbikeblog.blogspot.com/2006/08/shimmy-re-visited.html

 

[Todd Pepin]

I can confirm that my E3 Path+ will wobble when I ride no-hands above ~18 mph. I'll have to try it this week to see if I pin down the speed a little better. "Death" wobble, well maybe if I didn't damp it by grabbing the bars!

I'm somewhat new to a lot of the terminology. I found articles about "Death Wobble", but not "Speed Wobble". At any rate, holding the handlebar is fine until you get to about 30. The bike is stable below that. But I do have that wobble or thump in back wheel. That certainly doesn't help things either.

I'm glad I bought it through Amazon. I ran into the local bike shop owner who urged me to demand a replacement bike if the motor is in deed defective, given the age of the bike (less than 2 weeks old as of this writing) and the fact that Currie knew about the defect and sent it out anyway or if the motor is from the corrected stock, they may still have a problem that hasn't been determined or corrected yet. When he reseated the tire on the rear rim, he noticed the rear brake was dragging on the rotor. The brakes were supposedly checked and signed off on the quality control checklist that accompanied the bike. I also had attempted to contact Currie at least three times since I got the bike. The 800 number had a recording saying they were experiencing technical difficulties and could take my call, so I haven't been able to talk to anyone, yet. Amazon has their A to Z guarantee so in theory I can get a refund from them if I can't get satisfaction from Currie. From everything I've read, it sounds like Currie is good with support so hopefully it will get sorted out. I don't trust that the quality control checklist provided with bike was completed thoroughly or properly. Their were some discrepancies I wouldn't have signed off on.

 

[calvin]

Very disconcerting. I would first exhaust all of the normal channels provided by Currie Technologies to try and fix these issues/defects. If after a reasonable amount of time, you have not been satisfied, then "air" the problems at this forum. If the problems are fixed, then report that here too. I am starting to have misgivings about us slapping the manufacturers in the face with these initial problems in a most public way. I know if I had a problem with my Motiv Shadow, I would email or call Motiv and speak to Cameron or another employee. Only if that problem was not addressed properly would I think about posting it here. Motiv and I have a trusting relationship to maintain.

If I was the owner of an electric bike company, and one of my customers had a problem with his/her bike. I'd probably be pissed off if they started the whole conversation right here in the forum... Hey! Look here everyone: Calvin! What gives with the bike you sold me? The battery is dead! Gimme another one. Let's go! Hop to it!

I am exaggerating of course but you all get the idea. Use the established chain of command first, then the back channel if you must. When there is no response then become like Edward Snowden. I think that I'll start another thread about this.

 

[Todd Pepin]

Very disconcerting. I would first exhaust all of the normal channels provided by Currie Technologies to try and fix these issues/defects. If after a reasonable amount of time, you have not been satisfied, then "air" the problems at this forum. If the problems are fixed, then report that here too. I am starting to have misgivings about us slapping the manufacturers in the face with these initial problems in a most public way. I know if I had a problem with my Motiv Shadow, I would email or call Motiv and speak to Cameron or another employee. Only if that problem was not addressed properly would I think about posting it here. Motiv and I have a trusting relationship to maintain.

If I was the owner of an electric bike company, and one of my customers had a problem with his/her bike. I'd probably be pissed off if they started the whole conversation right here in the forum... Hey! Look here everyone: Calvin! What gives with the bike you sold me? The battery is dead! Gimme another one. Let's go! Hop to it!

I am exaggerating of course but you all get the idea. Use the established chain of command first, then the back channel if you must. When there is no response then become like Edward Snowden. I think that I'll start another thread about this.[/
I'm sorry if I've given a bad impression here. It's frustrating when you spend money on something to have it have issues. I could expect this from a $200 Wal-Mart bike. but, a $2200 bike really should have a little more quality put into it. It would be another thing if I'd been riding this for six months or year. It's mechanical, I understand that. It's going to need some servicing. But, two weeks and it has these issues? My hobby when not on a bike is my computer. I build my own machines, never would I buy an off the shelf computer. The one big issue in the computer business is there is almost no customer service. I've had to discard brand new out of the box motherboards due to defects. Thats take $250 or $300 and flush it down the toilet. Sure there's a warranty, but the manufacturer fights tooth & nail to void or invalidate it. If you do win the hoops you would have to jump through to get a repaired replacement when you bought new can be quite staggering, not to mention the downtime you would have to endure for such replacement. I guess I've dealt with that kind of stuff too much to trust another company. This bike is a mode of transportation for me. It isn't a leisure item or a toy. It needs to perform. I'm not being rough on it. It doesn't get exposed to the elements. I can park inside where I work. I did have to ride on wet roads once. But, it got wiped down and dried before I did. I'm doing everything I can to take care of it. Myself am not very mechanically inclined, so I will have bike technician do service and adjustments.

 

[JoePah]

I'm somewhat new to a lot of the terminology. I found articles about "Death Wobble", but not "Speed Wobble". At any rate, holding the handlebar is fine until you get to about 30. The bike is stable below that. But I do have that wobble or thump in back wheel. That certainly doesn't help things either.

I'm glad I bought it through Amazon. I ran into the local bike shop owner who urged me to demand a replacement bike if the motor is in deed defective, given the age of the bike (less than 2 weeks old as of this writing) and the fact that Currie knew about the defect and sent it out anyway or if the motor is from the corrected stock, they may still have a problem that hasn't been determined or corrected yet. When he reseated the tire on the rear rim, he noticed the rear brake was dragging on the rotor. The brakes were supposedly checked and signed off on the quality control checklist that accompanied the bike. I also had attempted to contact Currie at least three times since I got the bike. The 800 number had a recording saying they were experiencing technical difficulties and could take my call, so I haven't been able to talk to anyone, yet. Amazon has their A to Z guarantee so in theory I can get a refund from them if I can't get satisfaction from Currie. From everything I've read, it sounds like Currie is good with support so hopefully it will get sorted out. I don't trust that the quality control checklist provided with bike was completed thoroughly or properly. Their were some discrepancies I wouldn't have signed off on.

And that's the general problem with eBikes at the moment.. Many customers cannot buy local and local shops really don't want to deal with a new bike they did not sell, esp an internet electric bike. Under normal conditions you buy a $2k bike and if you have a problem, just leave it with the shop and let them troubleshoot.

 

[Todd Pepin]

Very disconcerting. I would first exhaust all of the normal channels provided by Currie Technologies to try and fix these issues/defects. If after a reasonable amount of time, you have not been satisfied, then "air" the problems at this forum. If the problems are fixed, then report that here too. I am starting to have misgivings about us slapping the manufacturers in the face with these initial problems in a most public way. I know if I had a problem with my Motiv Shadow, I would email or call Motiv and speak to Cameron or another employee. Only if that problem was not addressed properly would I think about posting it here. Motiv and I have a trusting relationship to maintain.

If I was the owner of an electric bike company, and one of my customers had a problem with his/her bike. I'd probably be pissed off if they started the whole conversation right here in the forum... Hey! Look here everyone: Calvin! What gives with the bike you sold me? The battery is dead! Gimme another one. Let's go! Hop to it!

I am exaggerating of course but you all get the idea. Use the established chain of command first, then the back channel if you must. When there is no response then become like Edward Snowden. I think that I'll start another thread about this.

I just wanted to thank you fo

And that's the general problem with eBikes at the moment.. Many customers cannot buy local and local shops really don't want to deal with a new bike they did not sell, esp an internet electric bike. Under normal conditions you buy a $2k bike and if you have a problem, just leave it with the shop and let them troubleshoot.

It really would have been nice to ride a few different bikes before buying one. My local shop had a Schwin that was a little overpriced and very underpowered (250 watt). But that's retail. They have to make a profit too.

 

[Ravi Kempaiah]

Todd,
As you mentioned, this is a problem with the structural design and motor.
There is not a single reputable eBike that has rear mounted battery and rear motor and doesn't rattle at > 25mph.
Center of gravity will be severely affected with most of the weight being in the rear and the polar moment of inertia at such high speeds will cause these problems. I have a friend of mine who traded his Pedego City commuter to get a Neo Jet. Handling changes substantially when you shift the weight from the rear to the downtube.

That is why the whole eBike space is evolving towards purpose built frames, mid- mount battery+ motor, lighter motor etc.

 

[Todd Pepin]

Todd,
As you mentioned, this is a problem with the structural design and motor.
There is not a single reputable eBike that has rear mounted battery and rear motor and doesn't rattle at > 25mph.
Center of gravity will be severely affected with most of the weight being in the rear and the polar moment of inertia at such high speeds will cause these problems. I have a friend of mine who traded his Pedego City commuter to get a Neo Jet. Handling changes substantially when you shift the weight from the rear to the downtube.

That is why the whole eBike space is evolving towards purpose built frames, mid- mount battery+ motor, lighter motor etc.

Fascinating.

 

[calvin]

Todd,
As you mentioned, this is a problem with the structural design and motor.
There is not a single reputable eBike that has rear mounted battery and rear motor and doesn't rattle at > 25mph.
Center of gravity will be severely affected with most of the weight being in the rear and the polar moment of inertia at such high speeds will cause these problems. I have a friend of mine who traded his Pedego City commuter to get a Neo Jet. Handling changes substantially when you shift the weight from the rear to the downtube.

That is why the whole eBike space is evolving towards purpose built frames, mid- mount battery+ motor, lighter motor etc.

I would agree with you here, I test drove a 500 watt 48 volt Pedego Interceptor. The acceleration was awesome, but because I "hung out" here before I got to looking for an ebike, I knew about the problems created by mounting the battery on a pannier rack. I noticed that at higher speeds it felt funny when I would weave the Interceptor in the road. I didn't like that sensation. The bike I have now doesn't do that, though it does remind me of the way a motorcycle would handle, which is okay with me.

This "death wobble" as you know occurs on standard human powered bikes too. I have not experienced this type of anomaly, but from what I have read the death wobble appears to have five or six possible causes, with potentially several simultaneously ganging up on the rider. I have read only the the hear-say on the sites that I linked to in the above post. The authors are credible I am sure ( one actually building frames), but they don't provide much documentation or references to back up their statements. I have not seen anything that has been "empirically verified" through experimentation or through testing of a bike broken in such way. It will be interesting to see if and how this is resolved.

Lastly, I think that we all have experienced vibrations when we have driven our cars and motorcycles. Most of the time these don't last too long as you continue to accelerate they disappear. I have talked to an engineer before about this, and he said it was caused by harmonics. So that's what I am guessing we are looking at here. Like in the video above, one of the the solutions is damping, which is adsorbing the energy faster than is is generated into the vibration. But don't you guys think that this "death wobble" problem should have been already figured out? I mean how long have bikes been around, 130 years or so?

 

[Ravi Kempaiah]

I would agree with you here, I test drove a 500 watt 48 volt Pedego Interceptor. The acceleration was awesome, but because I "hung out" here before I got to looking for an ebike, I knew about the problems created by mounting the battery on a pannier rack. I noticed that at higher speeds it felt funny when I would weave the Interceptor in the road. I didn't like that sensation. The bike I have now doesn't do that, though it does remind me of the way a motorcycle would handle, which is okay with me.

This "death wobble" as you know occurs on standard human powered bikes too. I have not experienced this type of anomaly, but from what I have read the death wobble appears to have five or six possible causes, with potentially several simultaneously ganging up on the rider. I have read only the the hear-say on the sites that I linked to in the above post. The authors are credible I am sure ( one actually building frames), but they don't provide much documentation or references to back up their statements. I have not seen anything that has been "empirically verified" through experimentation or through testing of a bike broken in such way. It will be interesting to see if and how this is resolved.

Lastly, I think that we all have experienced vibrations when we have driven our cars and motorcycles. Most of the time these don't last too long as you continue to accelerate they disappear. I have talked to an engineer before about this, and he said it was caused by harmonics. So that's what I am guessing we are looking at here. Like in the video above, one of the the solutions is damping, which is adsorbing the energy faster than is is generated into the vibration. But don't you guys think that this "death wobble" problem should have been already figured out? I mean how long have bikes been around, 130 years or so?

Hi Calvin,

I tried to articulate the wobbling effect using simplified physics we all know. [too much time on my hands + no sleep = more ebike stuff ]
This is very intuitive for any rider to understand and this is why great handling bikes have shorter wheelbase and low center of gravity.

All motorcycles are FSP and have good handling because the engine stays relatively close to the center of the mass. As shown in this video, polar moment of inertia plays a role not so much in the human powered bikes but becomes very pronounced in an electric bike. Bicycles have been around for a century but electric bike space is very slowly evolving.
Early 2000 bikes had terrible handling and specs but this has changed drastically.

some basic explanation in the video..

 

[Todd Pepin]

I would agree with you here, I test drove a 500 watt 48 volt Pedego Interceptor. The acceleration was awesome, but because I "hung out" here before I got to looking for an ebike, I knew about the problems created by mounting the battery on a pannier rack. I noticed that at higher speeds it felt funny when I would weave the Interceptor in the road. I didn't like that sensation. The bike I have now doesn't do that, though it does remind me of the way a motorcycle would handle, which is okay with me.

This "death wobble" as you know occurs on standard human powered bikes too. I have not experienced this type of anomaly, but from what I have read the death wobble appears to have five or six possible causes, with potentially several simultaneously ganging up on the rider. I have read only the the hear-say on the sites that I linked to in the above post. The authors are credible I am sure ( one actually building frames), but they don't provide much documentation or references to back up their statements. I have not seen anything that has been "empirically verified" through experimentation or through testing of a bike broken in such way. It will be interesting to see if and how this is resolved.

Lastly, I think that we all have experienced vibrations when we have driven our cars and motorcycles. Most of the time these don't last too long as you continue to accelerate they disappear. I have talked to an engineer before about this, and he said it was caused by harmonics. So that's what I am guessing we are looking at here. Like in the video above, one of the the solutions is damping, which is adsorbing the energy faster than is is generated into the vibration. But don't you guys think that this "death wobble" problem should have been already figured out? I mean how long have bikes been around, 130 years or so?

The sensation was the first time I ever experienced it. I've ridden regular human powered bikes before this and had never once felt like it was going to go out of control. This happened while coasting and going past 30 mph on a hill that is about a quarter mile long in length. This same hill on a regular bike, I've achieved 52 MPH at the bottom, having never had wobble. That was on a Trek street bike. But even a cheap Wal-Mart bike, and some dump hacks to my father had created never had it. I would have expected it out of the Wal-Mart Chinese made junk. What you are saying about weight in the rear makes sense.

But the wobble in the rear wheel is felt at any speed, accelerating, or decelerating. If I lift the rear wheel off the ground and trigger the throttle you feel the back of the bike wobble in your hand. It vibrates faster as the wheel turns faster. I'm just concerned that this vibration or wobble is causing stress on the dropout, frame or axle. You wouldn't want to have a failure at any speed. The technician at my local shop couldn't see if the wheel was out of balance but could feel the vibration. There's a shop who's an iZip dealer/service center just outside of Hartford, CT. I'll have to get over there and let them look at it. BTW, Is there a non toll free number to reach Currie? I've tried again to reach them and again I get a recording saying they are unable to take my call due to technical difficulties. How can I give them a chance if I can't reach them?

One more thing. Are these bikes supposed to be very difficult to pedal without power? I was in low gear climbing a hill and inadvertently touched the power button. The bike went to pedal assist mode zero and became extremely stiff in the pedals. Pressed it again and the bike turned off. One more press, it came back on and became easier again. As an experiment, I repeated this on a flat road and it had pretty much the same result.
Also when you stop pedaling, you feel a sudden burst of deceleration like the bike has some kind of governor that acts to slow you down. Perhaps it's due to weight in back again or the motor itself?

 

[Todd Pepin]

Hi Calvin,

I tried to articulate the wobbling effect using simplified physics we all know. [too much time on my hands + no sleep = more ebike stuff ]
This is very intuitive for any rider to understand and this is why great handling bikes have shorter wheelbase and low center of gravity.

All motorcycles are FSP and have good handling because the engine stays relatively close to the center of the mass. As shown in this video, polar moment of inertia plays a role not so much in the human powered bikes but becomes very pronounced in an electric bike. Bicycles have been around for a century but electric bike space is very slowly evolving.
Early 2000 bikes had terrible handling and specs but this has changed drastically.

some basic explanation in the video..

Thanks for enlightening video. That's well beyond me. I like to ride rollercoasters and know guys who could give engineering explanations like that for those. But just like the bike, I just want to get on and ride. The one question that begs asking is, didn't the engineers who designed these bikes take things like that into consideration during the design? Interesting video BTW.

 

[bikerjohn]

My Zurich has front wobble. I consider it a non-issue, (the issue is manageable with a one finger touch on the handlebar). There’s a spring going from the front fork to the downtube (called a deflopilator). A deflopilator seems to be an attempt to correct a basic design issue.

I only discovered the wobble because I like to ride without holding the bar on occasion. Realistically, there is no safe way to ride any bike "no-hands", wobble or not. Aside from my penchant for riding no-hands, there is no handling issue with the bike. It feels dependable and predictable at every speed in spite of the no-hands wobble.

So after reading about and experiencing the issue, it seems that there is a general tendency for many large frame and step-through designs to exhibit wobble. That would indicate a characteristic of frame design and a relatively high center of gravity. On e-bikes with rear rack batteries, a higher center of gravity seems like an obvious factor too.

 

[JoePah]

I'm not understanding this wobble issue.. I've had 2 ebikes for 5 years and never had any kind of wobble unless my rim was bent from an impact.. My A2b had a heavy rear battery, and while that really comprimised handling, it didn't result in any kind of wobble at 20 mph.. My Stromer is dead steady at 25 mph, although it is a hard ride.

That being said I woudl never ever buy an ebike with the battery hanging out the back.. it just kills the handling of the bike, imo.

 

[Ravi Kempaiah]

I'm not understanding this wobble issue.. I've had 2 ebikes for 5 years and never had any kind of wobble unless my rim was bent from an impact.. My A2b had a heavy rear battery, and while that really comprimised handling, it didn't result in any kind of wobble at 20 mph.. My Stromer is dead steady at 25 mph, although it is a hard ride.

That being said I woudl never ever buy an ebike with the battery hanging out the back.. it just kills the handling of the bike, imo.

I agree Joe.
This wobbling could be specific to this particular bike and it should be negligible for normal ebikes.
Both A2B and Stromer have very thick tubing to absorb the eccentricity of the load but thin bikes like path plus could behave differently.