Safe's Electric Bike Project #002

[safe]

I've noticed a substantial loss in pep from lead acid batteries when the weather gets cold.

You seem to lose your peak current capacity as it gets cooler, but the overall energy capacity seems less affected, at least with older batteries like mine that may have been a year or two old before I even bought them since they were one of those "super discount" special offers.

Practical Adaptation

The way to adapt is to stop "short shifting" and instead scream the motor out all the time. This has the effect of keeping the rpms into the "post power peak" area that is also better in efficiency. I did a 12 mile ride and started at 13.0 volts and ended at 12.1 volts which is about as good as I ever did. My average speed was right around 24 mph, but my top speed was way down. Before I could sometimes squeeze out a 26 mph average on the fastest rides. So basically if you sacrifice acceleration and avoid the too tall gears you end up okay, the battery seems to behave better if it's never forced to go to it's current limit. If you stay within a lower current draining regime the battery can sustain it, but it seems like if you overdo it the recovery takes a while.

It's fine for cruising around... just don't try to set any new track records...

Oh my god... I'm starting to ride like Xyster... ahhhhhhhhhh...

 

[xyster]

Oh my god... I'm starting to ride like Xyster... ahhhhhhhhhh...

You mean no longer like a 46 year old lunatic trying to relive his glory days as a BMX rider by racing around the same boring course over and over all summer like a dog with obsessive-compulsive disorder chasing his shadow around and around until exhausted he finally gives up and lays down for the winter?

And this is a bad thing?

 

[safe]

And this is a bad thing?

Of course! I miss my obsession with performance... without the ability to advance my speed all the time I'm just riding around looking at the landscape. There's nothing worse for a "sport" oriented person than having to "settle" for just cruising... though the weather is very beautiful right now so if there ever were a time for such a thing now would be it.

And just so you know...

30 years ago I was the same way. I built my own BMX track and spent all my time hanging out there.

20 years ago I used to ride on the street and had a regular 200 mile ride I did every week.

Then my "work years" happened and all the usual mundane trivialities of making a living took over.

And now I'm back to what I like to do... R & D on lightweight motorcycles and bicycles. It's been a life long passion of sorts. It's true that I raced and won back in the old days, but I was always more interested in the bike than establishing a racing career. Racing, I realized, is a job, a career, and unless that's what you like to do it's just a job.

I always see myself as "testing" something. What am I "testing" today? What can I learn today? What new idea might I add? That sort of thing... that's what actually is the thrill, but test riding is part of that overall dynamic.

Cruising... well... it doesn't satisfy me in any significant way.

But it's funny... what did I do while cruising? I invented a new game of "how to get the most out of a bad situation" and began running higher rpms to get the current down.

So you see my thinking... I'm not as you imagine... I'm a person that just happens to like to think and learn... it's fun for me.

 

[xyster]

Interesting. We're not all that different. I'm just flickin' ya wit.

I'm not into freaky-fast speed, but I am into torque, acceleration, and climbing steep hills. I enjoy designing and building bike mods around those amusements. I also enjoy just cruising, watching the scenery while thinking about other things. I like to combine the three -- cruise for awhile, find and climb a hill, and look out over the below while pondering the nature of it all.

 

[newbie electric rider]

Re; reading those last 2 posts

It reminds me of a autobiography I read about Warren Buffet. He still has a paper route. Of course he doesn't need the money, being one of the richest man in the world. It is while delivering his papers, that he achieves some sort of deep thought. Must be some sort of human condition, exercise, enjoyment, repetition, where you get into some Zen like state.

 

[safe]

Actual racers seem to have an attitude that the bike is a "means to an end" which makes sense in that their goal is to win races. Most young "yahoo's" know just enough about their bike to keep it running and then focus on the racing experience as an adrenaline addiction to speed.

I forget the name of the guy, but as I recall much of the true intellectual and intuitive advancements in motorcycle road racing technology in the 80's were developed by this Japanese "guru" who's job was to be the developmental lead for Honda's racing team. His first attempt at a bike was so extreme and wildly inventive that it had little chance of actually winning anything. But the process of "deep thought" and mystical discovery combined with Japanese self discipline helped him to refine his ideas until Honda was finally able to start winning.

The names of the guys that build the bikes are always forgotten... people remember the racers for 15 minutes and then they too fall away from memory.

In the end the personality that builds the bike is not always the same as the one that wins the races. Though, sometimes it takes a rider who knows enough about real world racing (by experience) to be able to provide practical feedback.

The best is when two people of different natures are combined in a team where one respects the other and they work together seemlessly. Those teams are rare... but when it works it works well... you end up with a "works" bike... :wink:

 

[dirty_d]

come on now, lets see some progress!

 

[safe]

come on now, lets see some progress!

I'm working on the front fairing and I could post something later today. The weather has been really, really nice and so I've been taking full advantage and riding a lot. It's actually dropped from oppressive heat to now a little bit on the cold side. (typical midwest weather, either too hot or too cold )

 

[safe]

New Pictures

Just some progress on the front fairing...

I figure that it's going to be easier to get the lower part close to where it needs to be before I get to the upper part. The upper part still needs to have a mount built for it then a clear bubble decided upon. (and actually bought)

I'm running out of the cleaning fluid to clean up after I mix the bondo, so I'll need to get more before I can continue... (once the stuff dries it's impossible to get off)

Note the interesting little "hook" at the bottom (just a style choice) and the curved-in shape that makes a pocket behind the front wheel. Since there's no radiator for cooling I think I'm probably best off letting the air escape downwards from the pocket. They often make the bottom "pointy" in order to trap the air in a pocket and force it into the radiator... obviously I don't need that... The only other reason to prevent the air from escaping there is that at high speed you will get a slight amount of lift. Somehow it seems to me that at 60 mph the lift would be small and would actually make the bike a little lighter and maybe even faster... so I'm unsure whether to go with the pointy shape or the smooth shape.

Another issue is to simply trap the air before it creeps into the pocket and you can do that with a front fender that divides the air around the front forks. My battery box is so narrow compared to the front forks that by the time you pass the forks the air is already as wide as the battery box. So to really seal off the front end the answer is a fender.

The "hand bubbles" or whatever you might call them will jut out really wide compared to the lower fairing. Basically the whole aerodynamics are designed around an idea of lifting the rider up pretty high and clearing the area underneath of air resistance. Notice how high the lower fairing is... on a motorcycle it could be as much as 6" lower because there's plenty of ground clearance for it. So the biggest aerodynamic object is my body and NOT the bike... the bike is only about 10" wide at the battery box, but my body is twice that at the widest point. The clipon handlebars have a width of 20" and my waist is at least 14" wide. So this will be wide on top and narrow on bottom.

 

[markcycle]

So I have to ask, is this a bike as in bicycle or bike as in motorcycle it seems like a motorcycle project to me. I'm curious why you don't call it a motorcycle in the posts. A Electric motorcycle is still a motorcycle.

 

[markcycle]

So I have to ask, is this a bike as in bicycle or bike as in motorcycle it seems like a motorcycle project to me. I'm curious why you don't call it a motorcycle in the posts. A Electric motorcycle is still a motorcycle. So should this post be in the motorcycle section?

 

[TylerDurden]

It's an electric bicycle... in Moussouri.

 

[Lowell]

I don't think it has enough power to be a motorcycle. Safe's state laws are rather relaxed, so he's lucky in that respect.

 

[safe]

So I have to ask, is this a bike as in bicycle or bike as in motorcycle it seems like a motorcycle project to me.

The federal law for an electric bike in America is:

1. 750 watts
2. Pedals are required
3. Top speed on the flat of 20 mph

So it's not a "bicycle" by federal law.

However in Missouri the "Missouri Moped Law" says:

1. 3 horsepower
2. Pedals not required
3. No clutches allowed

So in my state this will be legal as a moped. (no license required)

My Project #003 will be 100% compatible with the American Electric Bike Law and I'm hoping to use the same fairings on them. (same frame geometry too) I'll probably start with a 250 watt motor and trick it out to 750 watts / MCL / Forced Air cooling etc...

 

[ott]

250 watts?? You should be able to get that for free on this board. I would say thats way undersized for this nice machine your building.

 

[safe]

250 watts?? You should be able to get that for free on this board. I would say thats way undersized for this nice machine your building.

No, no... the one I'm building now will pump out some decent horsepower (1600 watts, 2.2 horsepower)... it's another project that I was thinking of afterwards that would be pedal powered and 250 watts. (Project #003... I'm on #002 right now) But even though the motor starts at 250 watts it will pump out a lot more than that after I get done with it.

 

[safe]

To Bubble Or Not To Bubble?

You can buy motorcycle windshields that fit popular motorcycles like the Honda CBR600RR and others for from about $60 to $80. Most of these bubble shaped windshields aren't much of a "bubble" at all, in fact they have almost no real curve to them and are mostly just a sort of cone shape. I'm thinking that the difference between using some clear plastic sheet that is bent in a cone shape is so small to that of the "official" shape that it seems hardly worth the extra money.

You can get away with a very small clear windshield and what's funny is that on many motorcycles they offer either "smoke" or "dark smoke" (nearly black) options in their windshields. Obviously they aren't selling these things with the idea that people will actually look through them. (the darker version allows no light through at all)

So why not drive the price down and use clear acrylic sheet?

If the result is about he same (which I think it will be) and you likely won't be able to notice much difference why not save $60 - $80 per windshield?

I've got at least three projects to make fairings for and the difference in price is as much as:

$70 * 3 = $210

...which could buy me many more of the batteries I need.

 

[Lowell]

Buy a screen from a wrecker that needs some polishing. I paid $10 for my used CBR screen and buffed the scratches out with a car polisher.

 

[safe]

Simulated Flat Cone Shaped Windshield

Yeah, I could hunt for used ones or buy new ones, but the amount of bend required is so small that it hardly seems necessary. Here's what I built out of cardboard. All I did was bend some cardboard and then laid some thin screen mesh over it and applied bondo. Quick sanding until it's smooth and then some primer paint and look at what you get...

Can you really even tell if there is a curve or not? (only from the proper angle can you tell)

It seems "good enough" in my opinion and if someone really wanted to mount a real windshield with the slight bend in it they could probably find a match with something at the motorcycle store. That shape you see has rounded edges, but the contour is flat.

So the idea at this point is to blend this shape into the other shapes and while keeping a close eye on all the clearances to keep "growing" this fairing until it all runs together well... sort of the "organic" development process. The handlebars stick out the widest and they will have those hand covering shapes, but studies show that the narrow windscreen is actually better because the helmet doesn't get bounced around as much. In the old days they used just one big bubble and that created turbulence. The new way is to have hand fairings and head fairings that are more or less separate. Also, in my case my lower fairing area is very narrow and since I have no radiator to deal with I can keep that closed off and small. The lower fairings only purpose is to get the air past my feet. (there's no big bulky motor to streamline) The lower fairing is only 10 inches wide.

 

[dirty_d]

you can use some thin plexi-glass and bend it like that.

 

[Beagle123]

Hi Safe:

One reason I wouldn't suggest using clear plastic of any sort is that they all tend to yellow in the sun and look ugly. I've never seen a convertable with a clear back windshield. If you could get something tinted, I think it would look better.

 

[safe]

One reason I wouldn't suggest using clear plastic of any sort is that they all tend to yellow in the sun and look ugly.

Isn't that because the plastic is left in the sun for days and days with heat getting trapped inside a car? It's true that over time plastic tends to yellow, but for the one hour per day I'd be riding that might take 25 years to happen.

 

[safe]

Lower Fairing Primed And Ready

The front fairing is a very difficult task. There are really tight tolerances and lot's of little bends that are not all that obvious beforehand. I'll be adding the upper front fairing parts later, but I finished sanding the lower part and got some primer on it. This is more or less how the lower part of the fairing will look.

Notice in the picture from the front of the bike how narrow the front fairing is down there. It's only 10" wide. So the front forks practically cover the lower part of the front fairing. That's why I was thinking that a fender attached to the forks would probably improve the aerodynamics a great deal. Another small project for the future I guess...

 

[TylerDurden]

I particularly enjoy watching your progress with the aesthetic elements of your motorbike, knowing that you have not even done a downhill glide to see if it tracks straight, or rolls steadily with a rider on it.

:lol:

 

[safe]

I particularly enjoy watching your progress with the aesthetic elements of your motorbike, knowing that you have not even done a downhill glide to see if it tracks straight, or rolls steadily with a rider on it.

No actually I've coasted around the neighborhood already and it handles great. I've built many bikes and motorcycles before, so I've picked up a lot of tricks over the years. I've been doing this kind of thing since the late 70's. (with about a 20 year gap in the middle where I didn't do anything but go to work)