Concept to reality - Build Thread

I somehow got confused and thought the original poster was Lithuanian.. Still, great English for a Californian! :twisted:

Seems we are in agreement on all of the basics, something modifiable, with a standard geometry, using off the shelf parts where possible..

I need to do some research on Chromoly Steel vs aluminum. Aluminum can be lighter, but is difficult to weld and must be heat treated etc. I was thinking it might make future mods easier with steel.. A weight penalty of 5-10 pounds would not bother me in relation to the gross weight of the bike and rider (I am about 160 lbs). Also not too sure about the price difference.

BTW, I am American too. My first trip to Asia was about 9 years, and nearly a year into my second trip! Hope my English is OK! :wink:
 
Sorry for the triplicate posts. Seems the forum is having some trouble tonight.

Yeah, I was wondering about the Lithuanian thing. Awesome though. I almost did teaching abroad out of school. I didn't find work before other things happened that prevented me from leaving.

So, tonight I worked on a rough mockup of what I want the bike to look like. Basically, more of a streetfighter style. Please forgive my photo editing and design skills. I am not creative or skilled enough to design something from scratch, so this is the best I can do with photoshop. The front fairing under the handlebars is particularly rough, where it has husqvarna graphics. I'm not sure how I'll want to shape that.
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Below is a slowly animating gif (5 seconds between transitions), so you can see how I am planning to modify the bike from the concept.
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The pics look good.

The only concerns I have is it seems excessively tall.. I have ridden a few thousand miles on trail bikes, so it is not a problem for me, but resale might be difficult as the locals are a bit shorter.

Please see this: http://hanoieasyrider.com/vietnam-motorcycle-tours/honda-xr-250cc/s41
and this: http://hanoieasyrider.com/vietnam-motorcycle-tours/kawasaki-d-tracker-250cc/s103
These guys are near me and their website shows some styles and shock travel distances for some of the bikes. Note, anything over 175 cc requires 200% import tax, so you pay 3x of base price. Wanting to convert something smaller and cheaper than that.. I could maybe measure some other bikes for suspension travel distances.

I am guessing the front shock travel would be in the 9 to 10 inch range and the rear nearly the same travel but at a 45 degree angle, so 70% of that vertically (square root of 2 is .707, and the magic number for 45 degrees..)? Street bikes look to me about half of that, maybe 5-6 inches but with vertical travel on the rear shock. Not planning on doing off-road, but with the motor at the rear swing-arm and wanting maybe 6 inches clearance under that, I may need the extra travel.

I think you mentioned seat height of about 29-30 inches? This would be at maybe 30% shock compression, with the rider on the seat, correct? ie, throw your leg over and the bike squats down with 70% of the shock travel still available for potholes etc.

And what size wheels are those? Here is a pic of the Kawasaki with 17" street rims, these look small compared to your pic above: http://www.motorcyclespecs.co.za/model/kawasaki/kawasaki_klx250d%20tracker%2004.htm

But, if we look here, at the 19" rims we get a 25" out diameter with a knobby tire:
http://endless-sphere.com/forums/viewtopic.php?t=55458
search for this "SHINKO 244: 19 X 2.75" on the page.
This is probably closer to the look in your picture.

Last, I would want a bit of a fairing covering the handle-bars, and all of the wires, hydraulic lines, displays, gauges, etc. Looks cleaner and it would be more aerodynamic.

Could you put some sizes on the pictures, in the interest of science?

Thanks in advance for your ideas!
 
Well damm.. While looking for specs I stumbled across this: http://www.vatgia.com/home/honda+wave+rsx+110.spvg
21,700 vietnam dong per US dollar, so only $1000 new, and 2/3 that used. May get me one, and lengthen the swing arm, and sell the engine, carb, and exhaust. Might have 10% VAT on that and a charge for plates ( I think about $10 for the life of the bike)
 
I think the dimensions are deceptive. I'm actually worried the bike is too small.
Draw an imaginary line from the hip, to bend in the knee, and down to the foot peg. The knee will actually be fairly close to the front of the bike.

Those are 17 inch wheels, I think it looks large because there is a lot of space between the wheels and the frame - but that is the streetfighter look.
bad_bikes_chocolate_streetfighter_04.JPG

Also, that Kwak 250 pictured is pretty large, even though the displacement isn't. Proportionally, dirt bikes are much taller and longer relative to the wheels.

Take this Ducati comparison. Left is a Hypermotard - a dirt-style bike meant for the street. And right is a ducati monster.
PRAMAC_MONSTER_PRAMAC_HYPERMOTARD_SC_PROJECT.jpg


The wheels relative to the body of the hypermotard are much smaller. Compare that my bike, where the body of it is actually not very big at all, smaller even than the Monster, relative to the wheels.

I'm estimating the wheelbase at around 1500mm, fairly small - Triumph Bonneville territory. Though I acknowledge the rear swingarm is a bit longer than normal - I want that for stability. This bike will already be light. If I make it too short, I worry it'll be twitchy at higher speeds, and give the feeling of being unsafe.

For seat height, as you can see in the gif, I've actually lowered the seat height - which is higher given that the concept has an Enduro/Dirtbike riding position.

Odd that suspension travel is a factor in taxation? I wonder why that is. But yeah, that bike looks like a good option for you.
 
For the heck of it I did a rough comparison.

I resized my bike down to where the rear wheel matched the ducati's rear wheel in height. Then superimposed the silhouette on the image.

Check it out. Granted the Ducatis are at a slight angle, but I think this really puts it into perspective.
 

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SHiFT said:
I think the dimensions are deceptive. I'm actually worried the bike is too small.
Draw an imaginary line from the hip, to bend in the knee, and down to the foot peg. The knee will actually be fairly close to the front of the bike.

Having problems visualizing this without some dimensions, or a standard sized human for reference..

SHiFT said:
Those are 17 inch wheels, I think it looks large because there is a lot of space between the wheels and the frame - but that is the streetfighter look.
bad_bikes_chocolate_streetfighter_04.JPG

Also, that Kwak 250 pictured is pretty large, even though the displacement isn't. Proportionally, dirt bikes are much taller and longer relative to the wheels.

Why do we want 17" wheels? I mainly care about Commercial Off The Shelf (COTS) for cost reasons, and something sturdy. 19" is not problem for me as long as it is not banging into the frame, etc.

SHiFT said:
Take this Ducati comparison. Left is a Hypermotard - a dirt-style bike meant for the street. And right is a Ducati Monster.
PRAMAC_MONSTER_PRAMAC_HYPERMOTARD_SC_PROJECT.jpg


The wheels relative to the body of the hypermotard are much smaller. Compare that my bike, where the body of it is actually not very big at all, smaller even than the Monster, relative to the wheels.

I'm estimating the wheelbase at around 1500 mm, fairly small - Triumph Bonneville territory. Though I acknowledge the rear swing-arm is a bit longer than normal - I want that for stability. This bike will already be light. If I make it too short, I worry it'll be twitchy at higher speeds, and give the feeling of being unsafe.

Not sure I see your point here, though longer is a sounds like it would be better, but longer WHERE? Longer swing arm? Longer body (cockpit area)? Both? If we put the additional length in the body, we could then use it for battery space! The swing-arm seems to me to be a quick and dirty way to increase ground clearance, and length if you have a stock frame. But with a custom frame, we can use a stock swing-arm, then lengthen the frame in the blue-print stage of planning. Also, are we still talking lower speeds, like 15-30 mph? We will probably not be competitive with the Ducati in any case.

SHiFT said:
For seat height, as you can see in the gif, I've actually lowered the seat height - which is higher given that the concept has an Enduro/Dirtbike riding position.

Odd that suspension travel is a factor in taxation? I wonder why that is. But yeah, that bike looks like a good option for you.

The limit for motos is 175 cc motor size. The police want to be the fastest as it is all too common to see two people on a moto stealing from tourists. One driving, and one grabbing.. 175 cc is an uncommon size, so about 150 cc is a practical limit. Beyond that the tariff starts to bite hard! cc's is a flawed measurement too, as 150 cc of Formula One would be maybe 100 HP.. No mention of RPM, high nitro racing fuel, turbos etc. Just measure the basic displacement. Buildings are taxed on width, so guess what the architecture looks like? :shock:

Note to self: Put "Turbo" sticker on new bike.. 8)
 
SHiFT said:
For the heck of it I did a rough comparison.

I resized my bike down to where the rear wheel matched the ducati's rear wheel in height. Then superimposed the silhouette on the image.

Check it out. Granted the Ducatis are at a slight angle, but I think this really puts it into perspective.

Smaller is easier to maneuver in tight spaces, longer is better for acceleration. Width is a problem in Vietnam, as "Big Bikes" show you have more money, and they take more space for parking. They stack them tight on the sidewalks a fraction of an inch apart. Small bike parking fee for a day is maybe 12k vnd, maybe 60 cents US. Anything "large" is double that. Not going to sweat that too much..

That said,what size do we "want". I think stick close to something stock, and maybe a few inches difference here or there. I have no "ideal" bike to aim for. I just want something build-able, reasonably off the shelf, and drive-able. There are many standard bike styles, so pick one that has some volume and has been widely tested, then tweak that. The experts have forgotten more than both of us can remember.. And do not forget the use case, daily driver city bike with some looks, wheely machine? Need to pick some constraints or we will debate endlessly.

Engineering is the art of managing trade-offs and constraints.
So, what is max torque of a Ducati? And max torque of maybe a 2 kw electric motor? A few inches of wheelie is OK, on my back wheelies, not so good.. Maybe we can agree to 2 inches more in the frame, leaving the swing-arm for a cheap welded splice mod for an extra inch or two if that is not enough?

Dunno. What do you think?

Anybody else in here reading this with some input?
 
Definitely.

I'm looking for 35-45 mph cruising, 50-55 top speed. No racing or anything, but not slow either. 17s are just standard, but yes, I have been thinking of 18s or 19s, as I do not want to use wider heavier motorcycle tires. Generally, 18 and 19 inch rims are used on the front, and there is a larger range of narrower and thinner tires for that rim size. So, I'm still considering that too.

Yeah, commuting is what I'm after, on surface roads, so the relaxed position with no stretching to get your feet flat on the ground should be very good for a confident ride.

Never considered the crime deterrent angle on the motorcycle size. Motorcycles used for crime like that is not something that happens here very often that I am aware of, but thinking on it, I realize it's common in many places in the world.

Thanks for all the input.

SHiFT
 
Ok, got it. expectations are now more realistic! yay..

my situation is cruise, max efficiency on the motor curve of 15 KM/hr and about 30 KM/hr max. Traffic is tight. you can sometimes touch about 10 people using both hands while driving. late at night, or an hour away, maybe get to 45 -50 km/hr, divide by 1.6 for mph, and we get SLOW driving conditions.

Fine. We can share a build, get the "look", and maybe some chicks.. I may need to change the final drive gears to a different ratio. OK, maybe $10 max.. including somebody knocking a link or adding one to the chain. Not a problem.

I am not "working" tomorrow, so maybe I can motivate and actually sit on some different motos and measure them.

Wanting comfort, not cramped riding style, Honda Cub 50 stretches me in ways my body is not ready for without some training. But that is boring, and ...

Then a bit taller seat, big motor on the base of the swing-arm, need at least 4-5 inches more height.
longer front shock, bigger rear too, longer swing-arm, some angle,

Best length?!? one.. Best height, best front shocks, I think more measurements before we start cutting and welding.
 
OK. I see your point regarding size.. The starter concept bike is SMALL. Like Honda Wave small..
Sorry it took so long for me to "see the light" ;)

The next size up is the 250's :
1) http://hanoieasyrider.com/vietnam-motorcycle-tours/honda-xr-250cc/s41 at 1400 mm wheelbase (55 inches)
2) http://hanoieasyrider.com/vietnam-motorcycle-tours/kawasaki-d-tracker-250cc/s103 at 56 inches
3) You had mentioned 57 inches as a starting spec.

This all seems very reasonable. 1500 mm sounds about right.

Now for the height of the handlebars? The dirt bikes above look to be at about 38-40 inches.
What do you think would be best? Cruiser or sport bike is what height? Maybe average the lowest of those with the 40 inch max above. Then use bent bars rotated up or down to customize for personal comfort? This would give plus or minus one inch maybe.

Width? Width of A123 prismatics is about 7 inches, so that would be a minimum, or 40152S 15AH HEADWAY CELL at 152 mm plus a case etc. 8 inches wide as a minimum? The QS motor I am thinking of is about 230 mm plus the drive shaft and 2 layers of 1/4 inch steel mounting brackets. We are up to about 250 mm for a max width, with some extra space for a different motor. Though the motor could stick out a little since the foot pegs would be in front of this. Motor is all the way back at the swing-arm mount, right?

So 8 - 10 inches wide (or deep in your pics)?

What are the final dimensions of your CAD frame design? Total length of the frame in its mounted orientation? Then how far do the front tire and forks extend forward from there. And how far does the rear-swing and tire extend?

Adding up to a total wheel base of 1.5 meters.
Height = ?
Width = ?

Thanks for your patient explanations..
 
I'm finding this very interesting and have lots of thoughts and have some mock ups of my own which may be of interest which I'll post tomorrow if I get time.

I will say that 17" wheels is the only way to go imo and 1500mm wheel base is actually quite substantial. Compare that to any 250cc sport bike, they're generally in the 1350-1400mm range.

Robert - I can't help but think that given the circumstances in Vietnam regarding speeds, traffic, parking etc that an ebike would be much more suitable for you? I commute every day at far higher speeds than You're describing and still have pedals. It would also take away any license requirements and be considerably cheaper and potentially faster in the real world where there's people everywhere.
 
Let me get the stats for you over the weekend.

As for the length, I agree. Comparing things as I have done on this thread, I realized that in mocking up the bike I have shortened the wheelbase. So now, even that Ducati Monster is only 1475mm or so and my mockup is shorter than that.

So I have to revise either the proportions of my bike or my expectations. I want a small bike, but not bicycle-like handling.

Also, Ohbse might be right there. If you just want a vehicle, and it doesn't have to look like a motorcycle/scooter, an ebike would serve your purposes too. But if you want the moto look, you have plenty of donor bike to choose from. I think the easiest way to go is with a dirtbike. The frame will likely have two main downtubes making a nice box for you to put your parts and batteries in. Where I think those Wave style designs will have a pretty funky frame that's not very conducive to customizing without a ton of fabrication of brackets and boxes, trays, and such.

SHiFT
 
Ohbse,

A few things, 17" wheels you feel potholes, 19" you feel them less.. I am interested in doing a mid-mount so a simple change of gearing fixes any cruise speed issues with motors in minutes. Bike shops everywhere. Might just put a few front drive gears under the seat! Pull over for a pit stop, swap the front gear, maybe make the rear wheel with some fore-rear range on the bolt. No chain mods for a gear swap this way.

I had a Honda Cub 50 in Cambodia for a daily driver for about 8-9 months, and it was too small. Check my profile for a recent post about ebikes in Viet Nam. 500 USD goes a long way. But I am average western sized, and usually tallest in a crowd here. These bikes do not fit me!

I also had a 90 cc Suzuki scooter in Nha Trang, Vietnam, fun city BTW (great place to retire), for about 2 years, a bit small for longer rides. Knees near chin = no good.

And I had a Yamaha 420 cc dirt bike in Cambodia which was light, nimble, and had scary good power. Front end up in any gear with the a twist of the wrist. But my collection of scars is hopefully complete, and while Doctors can be nice people, I am not eager to meet more on short notice! Things are a little more black and white here, as in no cash = no enter the hospital. "YOU GO NOW!" or DEE DyIE (rising tone on the eye part at the end), loosely translates as "get the f away before we have to kill you.." Still medical care is cheap, had a mole on my shoulder start scabbing up last week, went to the dermatology hospital, 5 USD for the consultation, about 30 minutes. Paid 25 USD for the stain test biopsy thing, had to wait 30 minutes before seeing the doc, and test,explanation was another 15 minutes. Results the next day by email. No cancer, but burning it off with a CO2 laser was $20 if needed. Took about 2 hours total! 30 minutes each way by bus for about 30 cents each way.

As for licenses, not sure what you mean, but I will address both possibilities:
1) No drivers license for less than 175 cc. None, no restrictions. Any age, anybody, foreigner or not, no license..
2) License plates - those cost about 10 USD when you buy the bike. They stay on for the life of the bike, no renewals, ever. This might be a slight theft deterrent. Ebikes have no plates.

No drunk driving laws either! so just go slow, and no problems. Hit anything as a foreigner, IT IS YOUR FAULT. Even being hit from behind. "If you were not in our country, there would be no accident. YOUR FAULT!"

And theft is always a concern. Everybody parks indoors. I can touch my under-desk beer fridge, my moto, and my TV from my favorite chair. Cars also go inside the house.. There is usually a ramp in the middle of the front steps of each house. Sometimes temporary wood or metal ramps are put in place, then retrieved after use, but many houses have a 6 inch wide concrete strip up the middle of the stairs.. Dogs and cats, go INSIDE THE HOUSE. Everything goes in the house.. Even plants are brought inside the house every night. All that said, I have never had anything stolen in over 4 years. Not sure what the penalties are here, but China when I was there 7-12 years ago, had the death penalty for about 600 USD of value. Total value after they search your house. Any serial numbers found reported stolen count toward the limit. The whole court case, beginning to END, usually drags on a few days.....

And a Honda Wave with disc brakes, used 2-3 years, is only $600. Toss the motor, stretch the frame and swing-arm and VOILA, ebike action here we come. Or just buy the front-end as parts, and have a frame welded, build/buy/steal a swing-arm, get a rear wheel with disc brake, and have no extra parts. Kind of like we are discussing here! ;)

I teach English, about 20-25 USD per hour tax free, so not a super huge expense for batteries and motor. Call it $2000 total, still much less than a cheap scooter back in the USA.

Wanting something upgrade-able, which the ebikes are not good for. With the smaller motorcycles/scooter, you get bigger everything, better brakes, and room to add batteries for speed or range. Better shocks, etc.
 
After careful consideration I have determined via extensive engineering and computer simulations that I would best be suited ....

Right, anyway, looks fast, with a "Turbo" sticker! :evil:

Might add an MP3 horn replacement with the "Racing Bike" sound. Want to see the traffic parting like the Red Sea in the movies! Airplane strafing sounds would be tasteless. Hmm, though maybe the large bus/truck sound might work too.. Anybody got an enraged water-buffalo digital sample? Open to suggestions :)
 
RobertC said:
A few things, 17" wheels you feel potholes, 19" you feel them less..

While that's true, it's not true because of the wheel size - it's because larger tires function as crude suspension. 17" wheels with good suspension will soak up plenty. There is a reason the majority of decent motorcycles use 17" rims outside of full size dirt bikes and some old mopeds, it's a good compromise.

Comparing anything to a Ducati monster it's going to end up looking pretty small, those are big full size bikes that weigh >170kg.

After some considerable amount of reading and research I have an idea that might work out.

A Honda CR85 is a small, lightweight two stroke motocross bike intended for teenagers in entry level competition.
2007-Honda-CR85Ra.jpg

It runs a 17" front wheel and a 14" rear wheel as standard. Wheel base is pretty short, 1285mm. It has 10.8" of travel front and rear and good sized disk brakes. Dry weight is only 65kg/145lb. 27 degrees rake and quite a lot of ground clearance.

Here's my quick and dirty photochop of what it looks like with 70mm longer swing arm, 2 degrees taken out of the rake and dropping the front fork 80mm, changing the rear tire for 17" and a little more 'naked'

cr85 mockup 2.jpg

The seat will require a bit of work to get angle and probably extended slightly to accommodate taller riders too.

Between the engine, fuel tank, plumbing, clutch assembly, exhaust and various brackets and tabs I think full rolling chassis could be in the 40kg range. Adding back in 15kg of motor, 18kg of battery, 6kg of controllers and wiring should be able to put together an 80kg package with geometry far more suited to street use, the power to weight comparable to that of the Ducati Monster you referenced earlier but far, far more nimble and probably quicker at lower speeds. Effective range at 30-40mph would be around 100-140km depending on riding style.

There are a vast variety of upgrades available in braking/suspension etc for this chassis and many people have modified them quite extensively. The best part is as they're not road legal and they're intended for teenagers the resale value is next to nothing. I've briefly checked local prices and I could pick up one for about $1200US in good working order. Selling a running engine/drivetrain could get me back $300-500 of that too.

I've started putting together more accurate drawings and model to ensure motor/controller/battery mounting. Only concern I have at this point is around chain run. As the motor can't easily be in the pivot with this chassis there will always be chain slack with suspension travel. That's definitely a concern with regeneration braking (which is awesome and essential). This is solvable with a bit of thought around tensioner placement I believe.
 
OK, CR85R specs here: http://www.honda.com/newsandviews/article.aspx?id=200706073522

Or, what about this? http://gokartsusa.com/Heist-Madass-Small-Scale-Motor-Cycles.aspx
Specifically: http://gokartsusa.com/YX127-CF-125-Motorcycle.aspx
Or this: http://gokartsusa.com/SSR-SR125-4-Speed-Manual-Mini-Dirt-Bike.aspx
Or these: http://gokartsusa.com/Pit-Bikes-SSR-Mini-Dirt-Bikes.aspx

Maybe something with a bit more battery space? http://www.alibaba.com/product-detail/motorcycle-three-wheel-motorcycle_60023833324.html?spm=a2700.7724838.35.1.riJuvx :twisted:

All new ready to go. No worries about prior maintenance etc.
 
Here we have a zoomed picture of a Honda Wave with some sense of scale

Points of interest:
1) 1400 mm wheel base
2) Front disk brake
3) rear regen would mitigate the crappy drum brake there.
4) working machine with all necessary parts for $600 used.
5) redundant engine and parts can be sold reducing the cost.
6) literally millions of these silly things in Viet Nam..

Proposed changes:
1) pretend the crankcase is an electric motor, moved rearward to where the grid lines intersect the kick-starter lever. This is our pivot point and motor mount with 1 inch Outer Diameter bearings on both sides.
2) remove all gasoline related stuff, engine, airfilter, battery, exhaust, etc.
3) add batteries and controller etc.
4) I want things a little bigger, so:
a) stretch the swing arm, add a new rear shock and longer front forks to make it taller.
b) put 19" wheels on to make it taller
c) some of both A and B

5) looking at the left 2/3 of the grid area, imagine mirror imaging the body so things slope *UP* to the handle-bars, or just taking the frame out, and putting in a combo frame/battery box sloping up from the motor and mounting plates directly to the point where the front end is attached.
6) drive it for a 1000 miles, then modify it as needed.

We can make the cockpit larger for comfort, we can make the seat height higher, we can raise the handlebars. Or weld up a new frame. Maybe make it a little wider to hold more batteries. change colors, add "Turbo" decal..
 

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Been a while since my last update, but I am still working on this bike. Slowly, but it's moving.
I now have design concepts worked up that I would like to share.

What are your thoughts?

EDIT:
My goal is to land on a form factor that is not quite motorcycle, but not bicycle either.

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Number 2 is definitely best to my eye, but number 1 also has potential.. Effectively raise the rear suspension and lower and reduce rake on front to that of number 2 and I think it will improve its perception.
 
On all of those the wheels look really big. I think stick to a stock donor base is easiest and then stretch it as needed.

Starting with a blank piece of paper adds a ton of variables, and things have habit of going wrong or being harder than they appear at the onset..
 
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