Helix Streamlining, 1 Year Progress Update
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- Опубліковано 24 лют 2009
- This is a 7 minute overview of the progress and insights Craig Vetter has learned during the first year of his work on creating a 100MPG scooter. Craig covers his work from the end of 2007 to the beginning of 2009 and shares the design truths that he has uncovered while he tested, modified and refined his "Freedom Machine" scooter
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Craig, I have been following your progress since day one really. My curiosity in maximum MPG and aerodynamics led me to your website through some time searching through google.
I am 21 years old. I bought a 2003 Ninja 250r last June, and the bike is a blast. I use it as my commuter vehicle and have stopped driving the truck. Currently i average 73mpg with this bike.
Thanks to your "journals" i have had this itch to find a cosmetically badgered Ninja 250 to turn into a streamlined gas sipper!
This is awesome. My friend just acquired a 2000 Honda Helix. We wanted one so bad when we were kids. Now as adults it's such a great practical bike. So neat to see how you were able to push this bike to its limits. It does tough to ride on windy days. This is inspiring to see how the streamlining can improve it!
Hi Craig, good work and video here. Several years ago I attended your workshop at Mid-Ohio Vintage Motorcycle Days. I hope you are still designing! I'm still thinking of building one of these streamlined bikes and collecting parts to do it. Thanks!
@craigvetter I certailny applaud you for the Freedom Project!
I had a 1970 Honda 100 that got 140mpg ... and would be easy to regear! I could hit highway speeds if I laid myself down on the tank. And I did for two years! Till I blew the camchain. Since I only paid $20 for the bike and the chain shattered the cylinder head casing, I trashed it. But that would be an excellent bike for the next level!
@craigvetter I believe the problem is "pumping losses". The faster a piston moves, the greater the proportion of energy is sucked up by the action of pumping the air in and out . So the next step is to adjust the engine characteristics to move the torque curve lower (or if like a diesel, it already has a really low curve, just reduce final gear ratio.) I changed a Mercedes 300D to 15" wheels and increased from 24 to 28mpg w no other changes! And that was WITH a fuel leak in the injector!
Stock gearing on the ninja 250 is 14/45 (a 3.21 ratio). I have my Ninja geared down with 15/39 (a 2.60 ratio). Besides good suspension and brakes, the ninja has "regular" size tires, and is very stable at speed.
Your tests prove a real life 20% fuel economy increase after streamlining. Some say that the ninja is pretty aerodynamic already, but i have no doubt that streamlining alone would push the ninja above the 80mpg range.... possibly in to the 90's!
There are some ninjas over 100k miles!!
Though I cannot understand well,I can feel his passion.
Randy Grubb might make a polished aluminum one-off body to your specified shape. He is capable of it, that's for sure. There are several who could, but they all want to be paid like kings.
I don't know specifically about the Helix but I know with the Chinese clone engines you can indeed gear up the final transmission so that you can have a bike that can go faster. Coupled with heavier weights in the CVT (the combination of which will be a blow to acceleration and hill climbs) will lower the engine RPM and with the aero-mod you will probably start seeing better mpg numbers. Note though: most 10" tires are not safe over 60 mph (J rating), the next bike should have 12-16" rims.
also.... i was interested to know if there is an optimum ratio for the front curve of the fairing... and by this i mean from a 2d perspective (top down)... Width vs Length (Horizontally).
Is it better to have the least possible amount of frontal area, or is it better to use the smallest possible "best" ratio of a frontal curve?
Brilliant work, can't wait to receive your 470mpg dvd!
What we need next is to know what fuel various engines will consume at a set speed, say 4000rpm in order to pick the most efficient one to build into a streamlined platform, my MuZ skorpion does 60mpg where the same motor in the Mastiff chassis did 50mpg, aerodynamics should improve this but but there will be a point where the engine is working under little load and will consume a certain amount anyway? Or am I missing something obvious?!?
@craigvetter there a guy who just built a streamlined Honda 125,he had a website devoted to the build,if I find it again I will post it,the funny thing,is it looks like one of your early bikes
I always liked the idea of a enclosed mc,ecomobile,monotracer.But with its high price and bad ergonomics,I too thought about a enclosed or partially enclosed scooter,with its ease of entry and low cost.I would love to build something and or buy a body I could attach.I would love to tour America at 70 mph getting 100mpg with a large group
@craigvetter
Hmm, and I'm looking to cut the cc in half (just working with what I got). Anyway, if you want to go 250, why not the Reflex? It has the 12/13 tires and you're already familiar with the Honda frame, plus the CN250 engine is pretty popular still so it should be relatively easy to find parts for (though gears are still a problem). Or are you after the manual transmission? I just don't see how you're going to cut a chunk off the front and lower the seat on a Ninja. Challenge for sure.
I really want to do this,buy a helix,put a aero package on it and see America on 4cent's a gallon.My concern is keeping the entry and exit simple,which is one of the great things about scooters,maybe a simple door way,or sliding the side back like a draw.I'm sure Craig will get it right.
I have an "improved" helix. But a yamaha. The cp 250 morphous. 20 hp, EFI computer control, 13 inch wheels, but basically a different take on the same platform.
Say Craig Vetter.. I have a copy of the Car Styling Mag issue 35 from 1981. Do you have a website showing what progress you have made on other designs since then? I too am an Industrial Designer and liked your environmental approach and wheelchair from that issue. Do you still have the place in San Lois Obispo? Plus do you have any designers that you hold in high regard? such as Henry Dreyfuss or Jacque Fresco? or others?
Well my old Mastiff did 70mpg+ when cruising and streamlining trucks buses etc (not reccomended!) against a normal 50mpg (Imp Gal) so it should improve with streamlining, how much is much harder to say, I do wonder how much of an improvement I could get out of a Honda CG125 which does 100-120mpg unfaired...
Btw, is there a European supplier at all for the Vetter/Rifle fairing?
Tnx GS
You might be thinking about Allert Jacobs; a friend of me. He is a well know recumbent and velomobile builder here in Holland. This is his website: wwwdotvelomobieldotnl/allert .He gets about 98 km/ liter (231 MPG)
How about using a big Burgman and swapping in a small diesel motor? They are already geared to run 100mph or more, the diesel should be plenty powerful enough.
I think a creative engineer/fabricator could swap a larger rear wheel/tire onto the Helix and give 20-25% more gear for top speed. Just a suggestion.
No room. An engineer had to alter his final gearing. Lots to read on his website.
The Helix is already a low rpm scooter. It's actually built to run at top speed, 70 mph, all day. That's not bad for ANY 250 single. They are also one of the most reliable bikes on the road with some having over 150,000 miles on the odo !
umaxen01 Hmm, There is a trade-off.
A single cannot really give much economy over such a wide rev range due to their lumpiness, Engines only smooth out while revving.
However, its around 300cc per cylinder that seems to offer most combustion efficiency.
Having a motor that offers low internal friction with all other losses reduced is deffo the key :)
I have a 2007 Yamaha Morphous. Thus is the Yamaha version of the Helix. Differences/ improvements (note, i owned and loved my helix! ) 249cc vs 244 disc brakes both wheels.vs rear drum on H. 13 inch wheels both ends on the M 12 front 10 rear H. Efi Yamaha. Carb Honda. These are only minor changes. I added a slight bit of temporary fairing around the sides of the cockpit and got an 80 mph top speed on the M. At 83 the engine cut out...(9000 rpm rev limiter) but STILL 60 mpg! I seldom go above 60 any more...
I removed the fairing because i don't "need" it. The morphous will go 60 mph plus into a wind with 3 bags of groceries and my fat butt.. and get 60 mpg.. not the 100 mpg you wanted, but it was not bad.. craig inspired me!