Metric Conversion Speed Trick, 20 to 28mph

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
If your bike is PAS governor limited to 20mph you can make the new cap 28 by using the metric conversion trick; taking it from Class 1 to make it Class 3. Let's say you have a display such as this: https://e-glidebike.com/images/sf-manuals/e-glide-SF-LCD-Manual.pdf. Kilometers are 40% smaller than Miles. 60 mph is 100kph. Reset the display to km from miles. Then reset the wheel diameter setting to 40% smaller. So, change a 26in wheel to 16 inches. Now your display will show that 25kph is actually traveling at 25mph, 40% faster. 20mph x 1.4 = 28mph.
 
So my class 3 bike … if i do the same procedure will it go faster than normal class 3?
@RunForTheHills is correct. If the amps are limited and cannot be changed, like 10 amps X 48V = 480W, you are stuck there. The same with a mid-drive and gearing if you are spinning out, you would need a larger chainring but might lose offset and climbing gears. If you do it, keep a log of steps you take so you can always go back. Also see if you can revert to factory default to start all over if you somehow mess up, so you can get back to home plate.
 
A speed derestrictor is an easier solution, and the data reported on the display are correct. Just saying :)
As @RunForTheHills said, the actual speed achieved depends on the motor power but also on the e-bike type. A drop handlebar is aero and facilitates hitting the high speed while the flat bar aerodynamically drags the e-bike as much as the achievable speed is some 22-23 mph unless a high power motor is used.

The trick as described by Uma might work for cheap Chinese e-bike motors but will not work with anything a little more sophisticated.
 
I looked into this when I got my Bosch powered bike. As I work at the dealer I have access to the full service interface so I thought a bit of monkey business might be possible.

Nope… when Bosch sells motors to manufacturers they lock the performance specifications, including wheel size, into the motor’s software before shipping.

dirty buggers.
 
I looked into this when I got my Bosch powered bike. As I work at the dealer I have access to the full service interface so I thought a bit of monkey business might be possible.

Nope… when Bosch sells motors to manufacturers they lock the performance specifications, including wheel size, into the motor’s software before shipping.
True.

dirty buggers.
Because they respect the law?
 
True.


Because they respect the law?
No, because in means that if you buy a used motor for your bike it can’t be changed to match your wheel size. My bike has 20” wheels, if I fit a used motor from a bike with 700c wheels the motor assist will cut out at 23kph instead of 32kph because of the wheels smaller circumference. That wheel size and its relationship to the speed limiter is locked down by Bosch.
 
No, because in means that if you buy a used motor for your bike it can’t be changed to match your wheel size. My bike has 20” wheels, if I fit a used motor from a bike with 700c wheels the motor assist will cut out at 23kph instead of 32kph because of the wheels smaller circumference. That wheel size and its relationship to the speed limiter is locked down by Bosch.
And one very good reason to avoid them at all cost.
You vvill use vvhat I sell you how I say.... ands furthermore you vvill like it.

No soup for you! 🙃
 
No, because in means that if you buy a used motor for your bike it can’t be changed to match your wheel size. My bike has 20” wheels, if I fit a used motor from a bike with 700c wheels the motor assist will cut out at 23kph instead of 32kph because of the wheels smaller circumference. That wheel size and its relationship to the speed limiter is locked down by Bosch.
It is because Bosch made that very motor for Europe. Use a derestrictor, and "Bob's your uncle" :)
 
You 'own' the dog, but someone else controls it?

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Yes, she is my wife, but another guy has his way with her and I can't even watch.


If you raised that dog from a pup, even with your ex-wifes help, would it still attack you if your wife or her new beau told it to??



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What does that say about you, if it does or doesn't attack You??


Is she still your wife?
If so, why??
 
If you are not the master of your bike, then it is not really your bike, it is someone else's, you are just paying to support it, but they, another guy, gets their way with it. You are helpless. Good bikes are owned by their masters and fully programmable by their owners.
Who controls your bike? Or dog. You or someone else? Who has the pants? Who owns the huevos, brains, and power over the thing? If not you then you are less than a cuckold. Good bikes are fully user programmable with the right to repair.
AI:
PedalUma eBikes
is an electric bike shop in Petaluma, California that champions open-source, fully user-programmable e-bikes and the right to repair. The owner, actively advocates in community forums that riders should retain complete control and interoperability over the machines they own.

🚲 About PedalUma eBikes
The shop specializes in custom electric bike conversions, upgrades, and complex electrical repairs.
PedalUma eBikes
  • Philosophy: They promote 90Nm torque e-bikes with open-source systems that are fully programmable by the owner via the onboard displays.
  • Technical Expertise: Unlike shops that strictly replace closed-system parts, their mechanics handle component soldering and direct work inside electric motors.
🛠️ Right to Repair in California
Your stance aligns perfectly with the current legal landscape. The landmark California Right to Repair Act (SB 244) mandates that manufacturers provide parts, specialized tools, and software diagnostics to independent shops and consumers. While many large e-bike manufacturers have actively lobbied against being included in these laws, shops like PedalUma prove that user-serviceable and open-source tech is highly viable.

📍 Local Bike Repair Alternatives in Petaluma
If you are looking for general maintenance or authorized service for proprietary major brands in the area, several other highly-rated shops operate in downtown Petaluma:

Are you looking for help sourcing parts for a custom open-source e-bike build, or did you need troubleshooting advice for a specific motor?

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11 sites

PedalUma eBikes - Ebike Conversions, Electric Bike, E Bikes
We offer a wide range of bike repair services, for all bikes including tune-ups, brake adjustments, tire repairs, and more. We ...
 
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If you are not the master of your bike, then it is not really your bike,

I voided my warranties on both my ebikes the day that they arrived.

it is someone else's, you are just paying to support it,

Both my ebikes and the battery on my first e-bike had problems.

I fixed the problems myself.


Good bikes are owned by their masters and fully programmable by their owners.

My "Monstrosity" as you call it, is Completely Owned And Supported by me alone.


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I refuse to kiss 💋 ass with any proprietary establishment.

I learned (with your help actually) to not buy a proprietary ebike.

Both my ebikes came with off-the-self brand name components that could be researched.

Nothing proprietary, except the electrics/electronics.

Who controls your bike?

I do.

I rode over 7,000 km last year.
Over 5,000 km were no-hands.

I can only go 32 kph, so I keep it interesting by riding no-hands.

The Best Days are when I have 20 mph crosswinds and I Have-To-Grab the handlebars to keep from being blown off the road.
 

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