Bike and Cycling Forum > Bike Forums > General Bike Discussion > Safe's Project #003


Reply
 
LinkBack Thread Tools Display Modes
Old 01-07-2013, 03:46 PM   #1
safe
Member
 
Join Date: Jul 2010
Posts: 67
Liked 2 Times on 2 Posts

Safe's Project #003






.


__________________
safe is offline  
 
Reply With Quote Quick reply to this message
Old 01-07-2013, 03:47 PM   #2
safe
Member
 
Join Date: Jul 2010
Posts: 67
Liked 2 Times on 2 Posts







.


__________________
safe is offline  
rynoman03 Likes This 
Reply With Quote Quick reply to this message
Old 01-07-2013, 03:48 PM   #3
safe
Member
 
Join Date: Jul 2010
Posts: 67
Liked 2 Times on 2 Posts





.
__________________
safe is offline  
rynoman03 Likes This 
Reply With Quote Quick reply to this message
Old 01-07-2013, 03:49 PM   #4
safe
Member
 
Join Date: Jul 2010
Posts: 67
Liked 2 Times on 2 Posts

What Creates eBike Pleasure?

Power?

What is Power?

Power is actually a derived value consisting of a combination of Torque and Rotation. Power can also be expressed as a combination of Force and Velocity. Changing back and forth is just a matter of conversion factors.

So is Pleasure all about Torque?

Yes and No...

The Pleasure Principle

Ultimately we come to realize that it's ACCELERATION that gives pleasure and not Power alone.

We define eBike Pleasure as:

Constant Positive Acceleration or Increasing Positive Acceleration.

We define eBike "dis" - Pleasure as:

Decreasing while still Positive Acceleration.

There is actually another area to consider which is Negative Acceleration (braking) and it also has three different modes:

Constant Negative, Increasing Negative and Decreasing Negative Acceleration.

...but that's another story.


.
Looking here at a typical 1000 Watt Mountain Bike we see how the GREEN area represents Acceleration "after losses". Losses fit into different categories like copper loss, iron loss, wind loss and hill loss. You can't really talk about the Pleasure until after you subtract all the losses because they all impact your riding experience. All these losses are specific to the motor, the gearing, the rider and bike weight so it's very hard to talk about anything in isolation.

We see in the GREEN area what is known as the "EV Grin" which is a very strong acceleration beginning at very low speeds (essentially at zero) that "fades out" after 15 mph. Riding this type of powerband gives a pleasurable experience up to 15 mph and then a great sense of disappointment afterwards. The "EV Grin" becomes the "EV Bummer".
.

.
In order to improve the Pleasure it's possible to "shift" Acceleration to a higher point in the powerband. In this example I've also adjusted for a lower Wind loss since the Road Racer concept focuses on improved aerodynamics over a Mountain Bike.
.

.
This extracts only the Acceleration of the two eBikes and shows how the 1000 Watt Mountain Bike "peaks early" and then fades away. For the 20 lbs of Force Road Racer the power comes on slower, but lasts longer which tends to extend the Pleasure.

Which is actually faster?

The truth is that they are probably very similiar. Long ago (2006) when I first started into this hobby it was all about going faster. But it wasn't long before it became clear that it doesn't take much to make something that is absurd... a poorly designed "motorcycle with pedals".

So my goal now is Pleasure... if the "Pleasure Principle" were to expand into actual racetrack action that's great, but for now I'm content that it's something I can enjoy.

My "Road Racer" is fun.
.
__________________
safe is offline  
 
Reply With Quote Quick reply to this message
Old 01-07-2013, 05:02 PM   #5
newleaf150
Senior Member
 
newleaf150's Avatar
 
Join Date: Nov 2011
Posts: 2,929
Liked 2291 Times on 1191 Posts
Likes Given: 5501

Very unique looking bike. Nicely done!

__________________
newleaf150 is offline  
 
Reply With Quote Quick reply to this message
Old 01-08-2013, 07:52 PM   #6
safe
Member
 
Join Date: Jul 2010
Posts: 67
Liked 2 Times on 2 Posts

It took many years of custom work, but it turned out really well.

The battery is a 12S pack of A123 20ah cells encased in fiberglass and they have turned out quite good. It's amazing how you can let them sit and they don't go out of balance or self discharge much at all.

The motor runs at a constant 40 amps on the "motor side" current and that's what makes the bike fun to ride. The "pleasure" doesn't stop until you reach full speed, but down low it's underpowered and that forces you to pedal.

I've made it an important point over the years that if you are to create an ebike the need to pedal should be built into the design. This does that, but it does it in such a way that you never feel short changed by the motor.

The "number one mistake" taking place in the ebike world is to not limit the power so that it's both fun and yet you are encouraged to pedal.

(too many overpowered ebikes)

This appears to have "found perfection" in that pursuit.

-----------------

The question about ebike performance needs to come down to quality verses quantity. I believe I've found the highest quality ebike experience because the performance is just enough to make it fun, but not too much to make it like a minibike or motorcycle.
.

__________________

Last edited by safe; 01-08-2013 at 08:03 PM.
safe is offline  
 
Reply With Quote Quick reply to this message
Old 01-08-2013, 11:28 PM   #7
Industry_Hack
Total noob (& forum admin)
TS_ADMIN.png
 
Industry_Hack's Avatar
Bikes
 
Join Date: Aug 2009
Posts: 11,089
Liked 3509 Times on 2039 Posts
Likes Given: 3443

Looks good, but how is it to pedal?

Industry_Hack is offline  
 
Reply With Quote Quick reply to this message
Old 01-09-2013, 02:46 PM   #8
safe
Member
 
Join Date: Jul 2010
Posts: 67
Liked 2 Times on 2 Posts

It's based on a BMX philosophy where you sit in the turns and then stand up to pedal. Below 20 mph aerodynamic losses are smaller, so standing up to pedal makes sense. Above 20 mph you stay tucked to get more speed and reduce aerodynamic drag.

The motor has been optimized so that it works at maximum power at maximum speed, so the whole package is designed to work together.

Many ebikes have tried for crude power, but few have approached this in the "big picture" perspective like this.

It's taken since 2006 for me to "finally arrive" at this... it wasn't easy.

-----------------

A typical bicycle wheelbase is 42". This ebike is 52".

As a result there is lot's of legroom... you can sprint without feeling cramped when you stand up. When sitting you would never pedal anyway.



The top speed is around 34 mph with this gearing and that's with about two horsepower, so pedal power would be meaningless because human power would only be a fraction of motor power. The best sprinters can sprint at these speeds for short periods, but this ebike would be able to hold this speed for half an hour.

It's at low speed... below 20 mph... where the pedals can contribute something meaningful to power output.

Choosing to "remove" low end power is a strange choice because it's saying I want people to pedal at low speeds, but that was intentional.
.

__________________

Last edited by safe; 01-09-2013 at 03:11 PM.
safe is offline  
 
Reply With Quote Quick reply to this message
Old 01-09-2013, 03:21 PM   #9
safe
Member
 
Join Date: Jul 2010
Posts: 67
Liked 2 Times on 2 Posts

20 mph Speed Limit

I'm fully aware that to sell an ebike it must not exceed 20 mph at the point of sale or face the dangers of lawsuits from anyone who buys it.

And each state goes about enforcing speed limits in their own ways.

By reducing acceleration it should calm people's minds about the ebike. It's usually when someone pops a wheelie that everyone notices. So if the ebike basically goes at the flow of traffic it would seem more natural.

-----------------

If it were to be sold as a product it would be limited to 20 mph.

.
__________________
safe is offline  
 
Reply With Quote Quick reply to this message
Old 01-11-2013, 06:05 PM   #10
safe
Member
 
Join Date: Jul 2010
Posts: 67
Liked 2 Times on 2 Posts



The next state I'm looking to move to has a "motorized bicycle" law that makes 30 mph perfectly legal.

It really comes down to how many teeth I choose for the front sprocket because I have to custom machine it myself. With a 100 tooth rear sprocket I have many choices if I want to gear it up (make the rear smaller) but I also can increase voltage.

At present my 24 tooth front sprocket is way too high.

This will make the ebike totally "street legal".
.


__________________
safe is offline  
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options

Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
My latest project :) MyBikeWorks General Bike Discussion 3 09-30-2012 12:11 AM
latest project trx1 Road Bikes 6 09-09-2012 05:42 PM
latest project trx1 General Bike Discussion 6 09-15-2011 03:18 AM
My latest project DirtyBobbysBikes Fixed & Singlespeed 38 03-24-2011 09:57 PM
I need help with lighting project. bones Gear & Accessories 12 11-13-2010 04:08 AM