Go Back  Bike Forums > Bike Forums > Advocacy & Safety
Reload this Page >

Electric Citi Bike Brake Issues?

Notices
Advocacy & Safety Cyclists should expect and demand safe accommodation on every public road, just as do all other users. Discuss your bicycle advocacy and safety concerns here.

Electric Citi Bike Brake Issues?

Old 06-24-19, 05:15 PM
  #1  
robertorolfo
Senior Member
Thread Starter
 
robertorolfo's Avatar
 
Join Date: Jul 2017
Location: Queens, NY for now...
Posts: 1,036

Bikes: 82/82 Lotus Unique, 86 Lotus Legend, 89 Basso PR

Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 594 Post(s)
Liked 36 Times in 26 Posts
Electric Citi Bike Brake Issues?

(I did a search for this and nothing came up, so my apologies if this is being discussed elsewhere)

https://nyc.streetsblog.org/2019/04/...under-the-bus/

So it looks like all of the electric Citi Bikes have been pulled for safety reasons. Personally I wasn't surprised to read this, having seen more than a few of them in the wild, but these cited "brake issues" are baffling to me. Does anyone know any specifics? I assume that the brakes themselves are fine, and the issue is around the center of gravity for the bike design, but I really don't know.

I did witness an electric Citi bike rider very nearly go over the bars after a pedestrian walked out in front of him, but he was going rather fast and my first thought was that he was a little over-zealous and clumsy with his brake application.

I know that @noglider has ridden these bikes quite a bit, so I'd be curious to hear his thoughts.
robertorolfo is offline  
Old 06-24-19, 09:17 PM
  #2  
UniChris
Senior Member
 
UniChris's Avatar
 
Join Date: May 2017
Location: NYC
Posts: 848

Bikes: 36" Unicycle

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 361 Post(s)
Liked 69 Times in 61 Posts
Originally Posted by robertorolfo View Post
So it looks like all of the electric Citi Bikes have been pulled for safety reasons. Personally I wasn't surprised to read this, having seen more than a few of them in the wild, but these cited "brake issues" are baffling to me. Does anyone know any specifics? I assume that the brakes themselves are fine, and the issue is around the center of gravity for the bike design, but I really don't know.
You assume incorrectly. Details of the incompatibility of roller brake and front hub motor previously covered here: https://www.bikeforums.net/northeast...tarted-30.html

In short, the roller brake is well (manual) and historically (all over the net) documented to require being paired with a hub with "power modulator" clutch capability to avoid excessive braking; but the chosen hub motor didn't have that manufacturer-required capability for use with a roller brake.

Last edited by UniChris; 06-24-19 at 09:24 PM.
UniChris is offline  
Old 06-25-19, 08:36 AM
  #3  
noglider 
aka Tom Reingold
 
noglider's Avatar
 
Join Date: Jan 2009
Location: West Village, New York City
Posts: 37,598

Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1973 Raleigh Twenty, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem

Mentioned: 440 Post(s)
Tagged: 0 Thread(s)
Quoted: 5688 Post(s)
Liked 260 Times in 181 Posts
I think I only rode the Cit-E-Bike four or five times. I didn't experience the problem. It only happened to people a few times, certainly enough to pull them off the streets. I think it was a mistake to provide a front-hub motor. I hope they don't do it again.
__________________
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog

“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author

Please email me rather than PM'ing me. Thanks.
noglider is offline  
Old 06-25-19, 01:07 PM
  #4  
Rick
Senior Member
 
Join Date: Feb 2007
Posts: 362
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 155 Post(s)
Likes: 0
Liked 35 Times in 30 Posts
I don't ride my bicycle on sidewalks public paths etc. Citi bike threw 1000 ebikes out there and there was a brake problem. The learning curve on a first time user had to be part of the problem. I couldn't find a detailed description or picture that explained the problem.
I think I only rode the Cit-E-Bike four or five times. I didn't experience the problem. It only happened to people a few times, certainly enough to pull them off the streets. I think it was a mistake to provide a front-hub motor. I hope they don't do it again.
What exactly was the problem with a front hub motor?
Rick is offline  
Likes For Rick:
Old 06-25-19, 01:16 PM
  #5  
UniChris
Senior Member
 
UniChris's Avatar
 
Join Date: May 2017
Location: NYC
Posts: 848

Bikes: 36" Unicycle

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 361 Post(s)
Liked 69 Times in 61 Posts
Originally Posted by Rick View Post
there was a brake problem.... I couldn't find a detailed description or picture that explained the problem.

What exactly was the problem with a front hub motor?
This was pretty much all covered in the existing citibike thread linked above, especially the specific brake incompatibly of the hub motor that lead to them being removed from service.

Last edited by UniChris; 06-25-19 at 01:20 PM.
UniChris is offline  
Old 06-25-19, 03:16 PM
  #6  
Rick
Senior Member
 
Join Date: Feb 2007
Posts: 362
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 155 Post(s)
Likes: 0
Liked 35 Times in 30 Posts
This was pretty much all covered in the existing citibike thread linked above, especially the specific brake incompatibly of the hub motor that lead to them being removed from service.
So there description of what happened was somewhat convoluted. Not knowing or seeing what the brake hub motor combo look like makes the problem unclear. Front hub motors are a simple way to electrify an existing bicycle. Now they have given the nay sayers in NY more power to limit the use of ebikes.
Rick is offline  
Old 06-25-19, 04:08 PM
  #7  
robertorolfo
Senior Member
Thread Starter
 
robertorolfo's Avatar
 
Join Date: Jul 2017
Location: Queens, NY for now...
Posts: 1,036

Bikes: 82/82 Lotus Unique, 86 Lotus Legend, 89 Basso PR

Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 594 Post(s)
Liked 36 Times in 26 Posts
Originally Posted by UniChris View Post
You assume incorrectly. Details of the incompatibility of roller brake and front hub motor previously covered here: https://www.bikeforums.net/northeast...tarted-30.html

In short, the roller brake is well (manual) and historically (all over the net) documented to require being paired with a hub with "power modulator" clutch capability to avoid excessive braking; but the chosen hub motor didn't have that manufacturer-required capability for use with a roller brake.

I read the entire thread, and the only thing is what you just mentioned: some "power modulator" that essentially acts as super simple anti-lock mechanism. So people were locking up the brakes, and essentially they are blaming the brakes as being too powerful?

I wonder what percentage of the electric Citi Bike riders had ever hit 18mph on a Citi Bike before (when not going downhill)? I wonder what percentage had practiced (or even contemplated) panic stops from 18mph? Seems like user error was just as much to blame here, and Citi Bike (or lyft, or motivate, or whomever runs the service) simply shot themselves in the foot by calling it a technical problem, thus opening themselves up to lawsuits.

As you stated before, govern the assist to 10-12 mph and all of the issues basically go away.

But, I will just add, that all of the naysayers were right in this case. The program didn't even last a month before they had to pull the bikes. So perhaps all those comparing the electric Citi Bike criticism to that of the program before it rolled out (in 2013), should offer up an apology?
robertorolfo is offline  
Old 06-25-19, 06:35 PM
  #8  
UniChris
Senior Member
 
UniChris's Avatar
 
Join Date: May 2017
Location: NYC
Posts: 848

Bikes: 36" Unicycle

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 361 Post(s)
Liked 69 Times in 61 Posts
Originally Posted by robertorolfo View Post
I read the entire thread, and the only thing is what you just mentioned: some "power modulator" that essentially acts as super simple anti-lock mechanism. So people were locking up the brakes, and essentially they are blaming the brakes as being too powerful?
An anti-lock brake has a lockup sensor; a power modulator just limits the torque irrespective of conditions, so it's not really the same thing.

Apparently a roller drum brake in contrast to other types just makes it too easy to unintentionally over-brake; while a highly skilled rider very in tune with their gear might be okay, the manufacturer doesn't want you running one without a modulator even on a personal bike, and these were share bikes targeted at an often inexperienced pool of riders and putting even experienced riders in a position of being unfamiliar with the unique feel of the particular example they would be getting on.

Seems like user error was just as much to blame here
Some of the crashes were cyclists of long experience

Citi Bike (or lyft, or motivate, or whomever runs the service) simply shot themselves in the foot by calling it a technical problem, thus opening themselves up to lawsuits.
Actually they held out and were silent about the issue until that became untenable.

As you stated before, govern the assist to 10-12 mph and all of the issues basically go away.
The traffic problems are vastly improved, but the brake problems exist even on a pedal bike that lacks a modulator, and predates e-bikes; it's just that the pedal fleet pairs modulator hubs with the roller drum brakes in accordance with the manufacturer recommendation.

Last edited by UniChris; 06-25-19 at 06:39 PM.
UniChris is offline  
Old 06-26-19, 03:15 PM
  #9  
robertorolfo
Senior Member
Thread Starter
 
robertorolfo's Avatar
 
Join Date: Jul 2017
Location: Queens, NY for now...
Posts: 1,036

Bikes: 82/82 Lotus Unique, 86 Lotus Legend, 89 Basso PR

Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 594 Post(s)
Liked 36 Times in 26 Posts
Originally Posted by UniChris View Post
An anti-lock brake has a lockup sensor; a power modulator just limits the torque irrespective of conditions, so it's not really the same thing.
Ah, I see, you are going to be one of these guys? Well, sorry, but you are wrong here. A power modulator is exactly what I said it is: a highly unsophisticated anti-like system. As in, it's a device used to keep the wheel from locking. Go play your games somewhere else.

Apparently a roller drum brake in contrast to other types just makes it too easy to unintentionally over-brake; while a highly skilled rider very in tune with their gear might be okay, the manufacturer doesn't want you running one without a modulator even on a personal bike, and these were share bikes targeted at an often inexperienced pool of riders and putting even experienced riders in a position of being unfamiliar with the unique feel of the particular example they would be getting on.
And that is EXACTLY why some of us (see that other thread you linked to), sounded the alarm on these bikes immediately. They are share bikes, with absolutely no prerequisites for experience or skill, that were capable of quickly accelerating up to 18mph in NYC. What could possibly go wrong...

Some of the crashes were cyclists of long experience
Annnnd, that does not preclude user error. I thought you were really into the whole logic thing...


Actually they held out and were silent about the issue until that became untenable.
They didn't have to label it a technical issue. They could have simply admitted that the program wasn't ready for 18mph e-bikes. The language they used was an open invitation for lawsuits.
robertorolfo is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
battradio
Electric Bikes
4
08-18-19 05:07 PM
dragonetr00
Electric Bikes
2
02-09-18 07:46 AM
corrado33
Bicycle Mechanics
11
10-27-14 06:31 PM
macteacher
Electric Bikes
4
01-20-13 10:36 AM
macteacher
Electric Bikes
9
10-30-12 03:04 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.