Cost-Benefit Comparison: Fast Electric Bikes and Motors

[Mike leroy]

Do you have a heavy load to pedal? Do you want to climb steep hills (10% grade) in 35mph speed zones? Do you want the thrill from going over 50mph on flat road? This terrain can be conquered with a TC motor, which defines my neighborhood. The Crystalyte TCxx motor family generates both high power and high torque. TC is an abbreviation for "The Crown".

I raced Brenda Wiley with the SF to LA Ride545 AIDS campaign on her Trek Lexa up my hill (in the background), while I ran on foot. "He easily beat my butt in less than 5 yards with energy to go". But she has reached 66mph on the downhill descent on the street in the background.

My goal is to find an ebike that easily makes it up the hill faster than the 35mph traffic. I run or walk the hill five or more times each week.

TC motors range from 72 to 96 volts and 50 to 85 amps. The watt range is 3600W (72V x 50A) and 8160W (96V x 85A). The top-speed range is 35 to 60mph. Torque starts at 131Nm for 72V systems.

"However climbing the 15% grade (also part of my commute), a 750 watt ebike will only make 7 mph, which is not too useful for commuting and creates a lot of unsafe traffic flowing past the rider since there is no bike lane there. To travel at 20 mph on this 15% grade with a 330 pound bike, rider and gear requires about 2500 watts (from ebikes.ca sim). 28 mph requires about 4KW."

The three 76V models are: TC65, TC80 and TC100. The numbers appended to TC represent speed in km/h for 76V. Each motor weighs 9kg.

The motor is intended for bikes like the following. At some point, the high power level requires a swingarm, as circled in blue.

(Link Removed - No Longer Exists)​

Some of the reasons I chose the frame are:

1. Split frame for belt and chain compatibility. Frame weighs only weighs 19 pounds.
2. The battery tank capacity is enormous, 26 Amp-hours! 52V, 26Ah NMC battery pack only weighs 16 pounds, but costs $1900.
3. The swingarm suspension for safe driving at 45+ mph downhill coasting speeds in two-lane traffic. My neighborhood also has 15mph speed bumps on hills with 30mph downhill coasting speeds. I will also take dirt paths that cut across residential streets. About ten concrete curbs meet the dirt paths at the street intersections. The ride is jarring. The 40mph downhill, potholed, tree-rooted, backroads are in a state of disrepair. My favorite backroad is one that I take, every chance I get.
4. All wires routed internally.
5. U.S. DOT VIN number to register in CA as legal motorcycle, should I choose that option.
6. A mail-order and service bike, so components must be the most reliable.
7. Configure the highest gear ratio possible with Rohloff IGH to pedal the largest chainring my legs can tolerate. My strategy is to rely on motor to power me through sub 20mph speeds. I will use a 50 tooth chainring to achieve speeds over 20mph without motor power.
   • Conceptually the Gates Carbon Drive front/rear sprockets are like a BMX no-gear bike.
   • The IGH provides gearing. The front/rear on a BMX is approximately 27:9, or 3:1. The Gates 55:19 is closest at 2.8:1 . Use this chart and calculations for the previous PDF doc to customize for your situation.
   • I probably need about a 1.6m display, so a 50:20 (2.5:1) is probably the closest match for my fitness level.

The first choice is picking voltage. Let's use the Revolution 5.0 configuration. A second 13Ah battery pack costs upwards of $2200.

Power- 5000W
Voltage: 90V , 55.5 Amps
Top Speed: 50+MPH
Max Range (@20 MPH): 50+ Miles
RockShox Boxxer front fork 203mm travel
RockShox RC2 rear shock- 8+" of frame travel
Schlumpf High Speed Drive (2.5X)
SRAM X9 Rear Derailluer/Shifter, 18 Speeds total
Standard CA V2.3
6061 T6 Hand Welded Aluminum Frame.
Weight: 82 LBS
Estimated MSRP: $8995

A second 78V 12Ah battery pack is $1400 and capable of 40mph. 78V seems more reasonable than the 90V system. Perhaps, contrasting the 78 and 90 volt system brings clarity to costs.

Revolution Sport
Power- 3500W
Voltage: 78V, 45 Amps
Top Speed: 45+MPH
Max Range (@20 MPH): 50+ Miles
RockShox Domain front fork 180mm travel
RockShox lyric rear shock- 7+" of frame travel
SRAM X7 Rear Derailluer/Shifter, 9 Speeds total
Standard CA V2.3
6061 T6 Hand Welded Aluminum Frame.
Weight: 79LBS
Estimated MSRP: $6995

The $2000 difference between the Revolution Sport and 5 is probably due to the battery pack and Schlumpf drive. I believe the motor is the same. The Revolution 5 controller handles ten more amps, but that should not affect cost significantly.

My approach to this bike is to custom order the components for the Revo 5 or Sport. I do not need the Schlumpf drive, which should be a savings of at least $500. The 90V provides an extra 5mph. I need to estimate the torque difference over the 78V minimum 131Nm . I doubt the 90V provides much incremental torque benefit over the 78V.

The controller is the critical difference. I would inquire about the maximum amperage supported by the 78V controller. My guess is somewhere between 45 and 55 Amps. My desired amp-to-volt ratio is 0.75. So, on a 78V controller, I would hope it could draw 55Amps, like the
Revo 5. If possible, I would upgrade the Revolution Sport controller to 78V, 55A. Upgrading the controller to 55A, should be the biggest bang for the buck. 90V battery packs are extremely expensive.

A 78V, 55A system is 4290 watts; halfway between 3500 watt Sport and 5000 watt Revo 5.

Let's take a closer look at the 78V battery pack. "String" is abbreviated by "S" in 21S battery pack. A string means 3.7V battery cells are connected together in a string of 21 cells to generate 78V. The length of the battery pack is 21 x 0.5 inches or approximately eleven inches. The cells are stacked two high, so 42 cells in a row. From the dimensions, infer eight columns or about 336 cells.

Each cell might cost $3.50. The cell in the following link costs $6. To make 13Ah battery pack from 2200mA cells, may cost approximately $1200. The actual cells are unknown and all estimates are educated guesses.

• Lightweight High Quality 78v (nominal) Li-NMC 21S battery pack with integrated full featured high performance Battery Management System for improved performance and drain rates up to 60A continuous.
• -3 to 5 year life expectancy depending on how well you treat it (manufacturer rated for 1000 cycels HOWEVER we have found this number not to be realistic if you seldomly ride your bike. Lithium batteries have a shelf life and will start to degrade after 3 year regardless of use.)
• -Two or more packs can be set up in parallel for extreme range (100+ miles!).
• -12.5AH will provide up to a 48 mile range 25AH can get you up to 96 miles! (Mileage estimates with 1500W Striker High torque power system traveling on Flat ground at 20 MPH).
• -Fully UN 38.3 Certified! These batteries meet the most stringent safety standards and have demonstrated the utmost in reliability in some of the most punishing (and expensive) testing procedures yet devised for portable lithium batteries.
• 78V 12.5AH pack: 13.4 lbs (LxWxH) 10.5" x 4.7" x 4.4" -
• I assume two can fit inside the revolution battery tank?
• 12.5AH- $1399
• FULL 1 Year Limited Warranty on all Li-NMC packs.

 

[Mike leroy]

I research and write articles in fits-and-starts, as my spare time permits. Writing an article usually takes one full week. So, check back regularly.

 

[Boh Inventing]

The market has yet to see an e-bike thats also an Up-right rider, e-razor, and up to 9 other devices in one. Whats the value proposition for this without the math? https://electricbikereview.com/foru...have-not-seen-or-tried-this.407/#message-3769

 

[Mike leroy]

The market has yet to see an e-bike thats also an Up-right rider, e-razor, and up to 9 other devices in one. Whats the value proposition for this without the math? https://electricbikereview.com/foru...have-not-seen-or-tried-this.407/#message-3769

Please look at my previous post.

Boh opened a conversation a few minutes before posting this. Here is the transcript:

Boh: Very cool way to get people best products. Interesting collaboration, NOT perfect. I ask the question how can you determine the "BestElectricBike," if you have not tried, nor seen all this e-bike concepts out there?

My response:

When did I say "Best Electric Bike"? I am making comparisons based on extensive research. I usually preface the articles with "Cost-Benefit: XXX". I am addressing costs and benefits, not riding experience. Information.

I respect the fact that you opened a private conversation, rather than making public attacks on articles I spent a great deal of time researching. However, I do not understand what the roles of other people are. I do not know you, nor your intentions.

Brambor has been openly flaming me on work that I put extensive work into. I wish you had contacted me directly rather than invite someone who openly attacks me.

I am sorry but I do not wish to have any further conversation with you.

Boh,
Perhaps we are not communicating. I consider your behavior atagonisitic. I told you privately: "I am sorry but I do not wish to have any further conversation with you."

I want you to cease all communication with me.

Since you are a NEW member as of TODAY, I would not be surprised if @Brambor is behind this.@Brambor was one of five people in the private conversation that s NEW member, namely, you started. Thinly veiled and beyond reasonable coincidence for a NEW member. You also continue @Brambor long-standing Flames against me.

Moreover, your question had no basis in fact. You conveniently avoided answering my request to demonstrate proof of your wild accusations. A NEW member would not typically behave in that manner without MANIPULATION. How well do you know the five people you invited for a private conversation?

What you do not know is my articles are the #1 Google search result for "electric bike cost benefit". The entire Internet will notice your post and draw an impression of you, based on your behavior.

Are you a puppet or tribal? The pieces of the puzzle point directly at @Brambor .