IPMBA News

Electric Bikes: Hype or Hope?

by David Cohen
MNCPPC Park Police Reserves, Montgomery Division

As an avid cyclist, my first reaction to the concept of an electric bike is negative.  By putting a motor into the equation, you reduce the health benefits of riding while adding a considerable amount of weight and complexity to the relative mechanical simplicity of riding a bike.  On further examination, though, the electric bike does offer certain advantages, including the ability to pull heavy loads and patrol faster and farther while still maintaining the advantages of bicycle patrol, including flexibility, maneuverability, ease of access, and stealth.

There are a number of public safety-specific electric bikes on the market, but their costs are very high, sometimes two to four times the price of a conventional bicycle, although still less expensive than a Segway.  Still, the price is high enough to make many departments reluctant to take the chance on a relatively unproven technology.

Our department was afforded a unique opportunity when an electric bike ended up in our Abandoned Property section.  The bike, a 1999 Giant LaFree, was generally considered one of the best electric bikes around during the nine years it was on the market.  Most bikes that end up in abandoned property wind up being shipped to a metal recycling center.  In many cases, smelting is an appropriate fate as some of these bikes are too weathered or missing too many parts to be rehabilitated.  However, a fair number of bikes that end up being recycled are quite salvageable.  This electric bike, while in pretty sad shape, fell into the latter category.  I pitched the idea of rehabilitating the LaFree and retaining it for departmental use to my supervisor, and she ran it up the chain of command, where it was approved. 

With the green light to proceed with the project, I put the bike rack on the back of my car to retrieve the bike.  This is where I encountered the first problem associated with an electric bike:  it is obscenely heavy.  It took two of us to load the bike onto the rack, and the bike was so tail-heavy (where the motor is) that it nearly twisted the rack.  The LaFree also has a very long wheelbase, far longer than your typical mountain bike.  I figured that would probably translate to better stability at speed, but at the expense of turning radius and maneuverability. 

Once back at my garage, I proceeded to tear down the bike.  Some of the components were quite familiar:  Tektro linear pull brakes, SRAM Grip shifter (the LaFree has a 7-speed rear and standard 26-inch bicycle wheels.)  The motor, battery, and wiring were a completely new animal to me.  After about two hours, the bike was torn down to its frame.  The serial number revealed that this bike was the 97th LaFree Electric Bike ever constructed.

I was unsure of the condition of the motor itself.  Getting it to work, obviously, was paramount to the success of the project. Without a motor, all you have is a very, very heavy bicycle.  When applying an outside power supply to the motor, I found that the motor was “bumping” – meaning it wanted to move, but something was preventing it from doing so.  The only way to fix this was to tear down the motor.
The motor consists of two components, a sealed electrical motor and then the mechanical transmission that helps assist with the pedaling.  I first worked on the electric motor.  After some cleaning, it was spinning freely.  The transmission, on the other hand, was still not moving.  The only way to fix it was to open it up.  When I did, all the parts spilled out.  I was able to put everything back together, or so I thought, as I ended up with leftover parts.  Uh oh!  It was time to reopen the transmission.

The transmission continued to be troublesome.  It would spin freely until I torqued down the bolts holding both halves together and then it would bind up again.  Once again, I took the transmission apart and discovered that the ratcheting gear was bent, causing the binding.   I thought, “Oh, who needs a silly ratcheting device anyway?”  Well, that didn’t work out too well as there was no way to pedal the bike without it.  I straightened up the bent gear and opened the transmission yet again to reinstall the ratcheting device.  I then hooked up the motor and applied power to it.  Finally, the motor and gears were happily whirring along.  Success!   

The next step was to hook up the wiring harness and the rest of the electrical system.  I cleaned up the frame in anticipation of re-installing the wiring harness.  The harness went back in, as did the motor.   I headed over to the battery store to pick up a new pair of 12-12 batteries (12 volts, 12 amps) to install in the bike’s battery pack.  Once they were installed, it was time to fire up the electrical system.   I turned the key, flipped the power on, and…nothing.  There was obviously a problem within the wiring harness.

Checking out various online forums revealed that the LaFree’s schematics are a very closely guarded secret and therefore not readily available.  Complicating the matter further was that while electric bikes are far more popular in Europe than in the United States, this particular LaFree was not sold in any kind of numbers in Europe, so there was a general lack of information regarding the bike.  

I knew I had a functioning battery pack and a functioning motor.  I figured all I would have to do is rewire the bike myself.  My first try bike literally went up in smoke as I attempted to run the full 24 volts through a low-voltage throttle unit.  I decided I needed some expert advice, so I consulted with Geoff Elliot of Green Pedals in Annapolis, Maryland.   Green Pedals is an electric bike shop; Geoff is a big believer in the e-bike and thinks it is a natural fit for public safety applications.  He pointed out the errors of my ways and recommended that I purchase a voltage control unit, which would allow me to use a standard e-bike throttle unit while keeping the wiring fairly simple.  I picked up one off eBay for $50 and waited for it to be shipped from China.

Meanwhile, I continued to work on the “bicycle” part of the electric bike, reconditioning just about every component that was attached to the bike.  New tires, new chain, new brake shoes, new cables, a new headset and a new shifter pod were all added.  Rusty parts were sanded down and reconditioned.    

I installed the voltage control unit upon receipt, but I was having issues with the throttle unit.  After lots of hair-pulling, I once again turned to Geoff Elliot.  He came to the rescue and pointed out that the older brushed motors required a certain kind of throttle.  Another order to China was in the offing.  When that finally arrived, I put it all together… and NOTHING!!!  I could not for the life of me figure it out, and after several attempts, I decided to set the project aside for about a month so I could work on other projects. 

When I returned to the project, I decided I would work my way backwards and unwire everything until I just had battery and motor again.  I got to that point, and still had nothing.  It was then that I saw my problem:  the battery terminals had been bent again and the power from the battery pack was not being delivered.  Once I fixed that, the motor came back to life.  This time, when I rewired everything, it all worked.  It was like Dr. Frankenstein giving life to his monster!  With the electrical issues solved, I had gotten over the toughest hurdle, and I knew this bike would be returning to the road.

After about 45 hours of labor, the bike was ready for its maiden voyage.  The LaFree was initially a “pedelec”, meaning that electric power would only be delivered if you actually pedaled.  It became very apparent that even though the new wiring harness enabled the bike to be run on motor alone, it worked far better when you were actually turning the pedals.   

The first ride revealed the usual squawks:  handlebars, brake levers, and derailleurs all needed adjusting.   It also revealed that the bike is slow, with maximum sustained speeds on level ground of about 15 mph.  Over a 4.5 mile course around my neighborhood, I actually achieved a higher average speed on my conventional bike than on the electric bike.  While the bike was slower than a conventional bike, the amount of effort used during that first ride was comparatively minimal.  Basically, it is the physical equivalent of a brisk walking pace, at worst.

Absolute speed, though, was not a requirement for this bike in its role with the volunteer patrol.  In fact, its lack of speed makes it ideal for operating alongside conventional bicycles, and makes it far easier to tame for the less experienced rider. 

As I had observed when I first brought the bike home, its long wheelbase and low center of gravity give it an amazing amount of stability.  It also has a very comfortable upright riding position, making it an ideal observation platform. 

The remainder of the fall was spent on test rides, checking battery life and continuing to make adjustments to the bike.  Hopes for getting the bike out into the field were dashed by the very cold and very snowy winter.  

During the winter months, the bike simply sat in my garage, along with my “conventional” bicycles, just waiting for the weather conditions to improve.

Towards the end of March, the weather began to show enough improvement that riding became feasible again.  A bicycle training class was being held for the newest volunteers who passed through our Volunteer Academy.  Volunteers go through 24 hours of classroom training followed by another 12 hours of field training before they can go to their “specialties” such as horse or bicycle patrol.  The training course we use comprises one hour of classroom instruction, one hour of cone course instruction and then a one-hour trail ride.  I am the Volunteer Instructor for bicycle, so it seemed to be a good time to try out the electric bike.  My observations are as follows. 

The LaFree has a very long wheelbase, making tight turns required by the cone courses somewhat challenging.  The bike’s heft and low center of gravity due makes it very stable in low speed maneuvering, overcoming the difficulties of handling a longer wheelbase bicycle.  Curb-hopping was no different than on a regular bike, although with the considerable weight, riding off the curb led to a pretty hard landing.  The braking left something to be desired, but given the bike’s heft, it did an adequate job of stopping the bike. 

Trail riding revealed this bike’s biggest downside; it climbed with the agility of a tortoise.  With the bike in its lowest gear and the motor running wide open, the bike would still bog down on moderate inclines.  Adding pedal effort is a must.  On sharp climbs the bike could manage no more than three mph.  However, it would make the climb without over-exerting the rider, who just needed to be patient.  The trail ride also confirmed that the bike is an excellent mobile observation platform and is comfortable to ride for prolonged periods.

After proving the LaFree had the potential to be an effective tool, it was time for it to prove itself under real world service conditions.  No trial could be more effective than the annual detail at Black Hill Regional Park in Boyds, Maryland.  Once per year, an Iranian-American group rents out the entire park for the Nowruz Celebration.  Crowds of 3,000 or more are not uncommon.  With this many people in the park, a significant presence from our department is required to ensure that the patrons are following the rules.

The role of the bicycle patroller is to rove from checkpoint to checkpoint in the various parking lots as well as ride the trails in the park’s interior to monitor the crowds.  This part of the park is very undulating and a rider will have anywhere from 120 to 150 feet of climbing per mile.  In short, if the LaFree performed well at Black Hill, it would perform well at any of our other parks and trails in the County.

We were greeted by a sunny, but cool, morning the day of the Persian Festival.  I brought both the electric bike and my regular ride (a Trek 6500) as a backup.  I parked my car at the police substation and then rode approximately 1.5 miles to the center of the park.  At the first hill, I encountered a horse-mounted volunteer.  The LaFree chugged up the first hill, keeping pace with the horse at a walking speed.  Once we got onto the flats, the electric bike pulled away from the horse and I joined two other bicycle patrollers in the center of the park.

The bike proved to be a good match for the conventional bikes.  Its speed on the climbs was no worse than the other two volunteers riding with me, and I was far less winded at the top of the hills than either of the other riders.  We had to navigate our way around crowds milling about and seemingly unaware of our approach despite our warnings.  Again the LaFree proved to be extremely stable in low speed maneuvering, and adding a little bit of throttle helped keep the bike upright. 

Totally unexpected was the amount of attention the bike received.  It was quite the conversation piece! I was stopped by park guests, uniformed officers and park maintenance staff, all inquiring about the bike.  The general consensus was that it is a very cool machine.  Some of the officers remembered what this bike looked like just one year before in Abandoned Property, and could not believe its transformation.

After about two hours of riding, I switched to my conventional bike.  I did not realize how much of a help the electric motor had been until I started pedaling up the same hills I had ridden earlier on the electric bike.  While I enjoyed the lighter weight and much quicker responsiveness of the Trek, I have to admit, I missed having that extra boost.  After another two hours with the Trek, I went back to the electric bike for the final two hours of the detail.

The detail itself was fairly mellow.  We did not have the kind of parking issues that we had in previous years.  The most serious items were permit disputes about who was supposed to be at which picnic shelter, patrons bringing propane cookers to the park (which are not allowed), and a handful of dogs that were off lead.  All of these were addressed by the bicycle-mounted volunteers, as we had the flexibility to be able to get to the various places where the patrons were congregating.

With a half hour left in the detail, the battery was no longer putting out enough power to climb the steeper hills.  I had to do some out of saddle climbing to help get the bike up the hill.  The out of saddle exertions were far less than they would have been, even with the diminished assist that was available to me at the time.  I was offered a ride back to the substation, but I wanted to see how much was left “in the tank” on the bike.  The substation is at the end of a long uphill, and by the end of the uphill, the motor was barely putting out, so I had to go out of saddle to go the last 20 yards. 

Overall, the day was a success.  No major incidents occurred and the patrons were able to enjoy a day of beautiful weather.  The electric bike proved it could work at one of the two biggest details our department works (4th of July fireworks being the other), and did so at the park with the most undulating terrain in our system. 

Mind you, this particular bike is a first-generation electric bike, using late 1990s technology and weighed down with very heavy, lead acid batteries.  Even with these handicaps, the electric bike proved it could be an asset to the department.  A modern electric bike, with more powerful motors, lighter, longer-lasting, and more powerful batteries would have had significantly increased performance.

The electric bike’s performance at the detail was brought to the attention of our department’s bike patrol sergeant.  It interested him enough that the department is looking into the possibility of utilizing modern electric bikes in the patrol role.  The evaluation of a modern electric bike will be the next chapter of this story, so please stay tuned to your IPMBA News!

All photos by David Cohen.

David Cohen has been a volunteer with the Maryland-National Capital Park Police, Montgomery County Division, since 2007, and is an avid cyclist both on- and off-duty.  Besides tinkering with bicycles and putting old electric bikes back together, David also enjoys working on vintage British sports cars and World War II era aircraft.  He can be reached at onyxsax@aol.com.

(c) 2014 IPMBA.  This article appeared in the Spring 2014 issue of IPMBA News. 

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