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R&D Assistant Engine Bicycle

07/21/2014 8:33 AM

Well guys,I guess that some of you remember my endless questions about 1-2 yrs ago all about how to use the honda GX25 engine [1hp- 7000 r.p.m] to power a mt. bicycle. But few days ago I biked up a very steep road,on the second low gear, without my own muscles aid. The challenge was to reduce from 7000 r.p.m to 70, the reason is that the engine should power the bicycle's crankshaft,all this to enable me to continue to pedal up nearby mt.Gilboa. For a 76yrs old person, this would be the optimal solution- to use what is left from my own power and fitness, and travel on the Mt. Gilboa ridge.The reason that I preffered a petrol engine and not and electric motor was the limited range for a battery with an enormous weight. 1 bottle of gasoline can take me much more far and high than a battery!I solved the problems of the reduction gear with a wash machine drive belt,because this kind of drive belt can be used for a wide range of pulley's diameter- the output from the engine was 16 m.m pulley that drove through the belt a200 mm pulley. This belt enabled me to reduce from 7000 to 700 r.p.m while I have very limited space on the bike. . On the shaft of this pulley sit's a 9 tooth sprocket that drives a chain to a 65 tooth sprocket, From 700 to70 r.p.m , which drives the crankshaft that is conected to the pedals.As I purchased this engine, I wasn't aware that Bimoto in Poland is using the same engine, and developed a gear that fit's well for the same purposes like mine, but- as I said- I didn't know about it! So I went my own way, but I consulted lot of machine engineers .Since I'm a retired kibuts member, and I'm still supporting my kids, I have no money. If I would know how much work will require to construct [in fact to develope!] this bike I would't go for it![You remember- time is money]- Now I have to pay lot of money to Meir, the guy who did for me this job- fortunately, Meir himself became very enthusiastic of this project, so he demands only a fraction of what it would cost in a real world! Meir is older 1 yr than me, he is a trained craftsman machinist, still working few hours a day for the fire setting machines factory, of his kibutz - Beit Alpha. I had no idea, that this project will last for 2.5 yrs [from the day I purchsed the engine]. If I knew how much time and money it will take- I wouldn't do it. Well, what did I gain from this project?I've to admit that I do not think that I'll travel on the hills, as I planed 2.5 yrs ago.But I had a very challenging learning time for me: Lot of mechanical engineering, including lot of calculations, and I learned that to develope an innovative contraption isn't that easy as I thought! It was a very important lesson for me, because I suffer from "hyper creativity"- It was a necessary lesson for me to accept the insight that I may have many ideas- dreams, but they will stay dreams,and I have no chance to implement them!And today I proved another idea: I attached 2 wood bars on the rear carrier, that were longer than the carrier, and I put a 1 kg. weight on the far edge, so the distance of the weight from center of balance, added 3.5 kg.! I took the bike to the bottom of a steep slope, and while I'm walking aside the bike, I pressed the gas lever to gain 4000 rpm,below- the centrifugal clutch wouldn't engage the engine to the wheels.I walked carefully aside the bike, watching not to be hit by the pedals that were turned by the engine,[1:100 relatively to the engine rpm.] As I hold firmly the handle bar- the bike pulled me up the slope!As I did the same without the extra weight, the wheels spined, not able to pull me up!As I designed the bike, most experts told me that it is a bad idea to conect the engine together with the legs power, they suggested to add some rachet, that will enable seperation of the legs work to the engine's revolutions, but I was confident that when I feel uncomfort with pedalling, all I have to do is to release the gas lever, that will result disengage of the clutch, and then the bicycle will move on the inertia of momentum for some distance, according how fast was my biking, and what kind of road it is. And really, it is perfect!But- if I want to pedall without the engine, I have to take off he drive belt, otherwise, the revolutions transfered from the pedalls through the chain and belt to the engine's driveshaft, will encounter friction of the centrifugal clutch! It will be a very tough task!Now there should be the "economic bottom line"- does the expense of 11000 nis [altogether] pay off?As I told you before there are "of the shelves" solutions for what I wanted.But when I consider this project from the perspective of my age, this is the first time that I achieved, [because I didn't realize how much it will cost] such a project.But now I'm happy that I did it, and that I proved my concept.This encourage me to continue my own way, and not to let my age to hinder me for going further!

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Guru
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#1

Re: R&D Assistant Engine Bicycle

07/21/2014 9:27 AM

Nice post... would have been even better with pics as I'd like to see it.

Del

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#2
In reply to #1

Re: R&D Assistant Engine Bicycle

07/21/2014 11:36 AM
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Guru
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#3
In reply to #2

Re: R&D Assistant Engine Bicycle

07/21/2014 12:48 PM

So that's what we call a moped in the UK...

Del

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#4
In reply to #3

Re: R&D Assistant Engine Bicycle

07/21/2014 1:12 PM

tomorrow inshalla!- [I guess you what does it mean!] I'll send the pictures.

Not the concept is new, the wash machine belt is the innovation here.

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#8
In reply to #1

Re: R&D Assistant Engine Bicycle

07/23/2014 4:02 PM
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#9
In reply to #8

Re: R&D Assistant Engine Bicycle

07/23/2014 5:13 PM

That is a nothing post!!!

Can you redo it?

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#10
In reply to #9

Re: R&D Assistant Engine Bicycle

07/23/2014 11:08 PM

I didn't understand your comment!

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Guru

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#11
In reply to #10

Re: R&D Assistant Engine Bicycle

07/23/2014 11:20 PM

The image you tried to post does not appear to us. When I try to inspect the URL for the image, the best I can get is this comment from Google:

Your client does not have permission to get URL /S_egoCFWo3ng5JPf5r1lo-ck6CEn_1KtoRY615kq-6n2YK0fm23C_86QJURatiSlLwbns8Ra7q8raFH4bkqqvwvm9aSPwWJ9zaEo5fQcrZ8CCFpMUuXRoEdYbbPkqF1qMVAuGR016E-4A-cP2p32oJQTOx0-Np3bZuC8MPsukMwK9bVqTy2ndWbHmqCJotqcRYMeImOF8nvk3eGj97JoiXHoOd-v4Ihxyvxi34I0Mtde1mOQTGUG3LA-1sIBYY6iH7tF_unRq_ji34YlTG0krASyTe0YQDRyZ0k7Z-3Rbi_br5QB4LvxJ3gQUpR1GjeL3CS3Q1qWY9o5UL3cpUlOZe84RgBML1tR5mnxbTnJLIHaUoZCJqJa1PCSeCrRmP6F5Z7U5EBAmDIboMLp-bOk0eua3PrxwyFwz_d_OBR57Vucp7_LVFah9doIfQhLIZkrpWnTse3YunzMzNMvjCUFmK4NoWk3YiO5X_NuS_-aPkUS0P3OjEBvbwonByNQQLzKQ6Stgptg0E45AXMHTpMEO4C5TrgXtp0ZCSqLCEmOR2ko8-2PJFru_MaOK1O5JQqNTVz8IW9QgA=w1342-h523-l75 from this server. (Client IP address: .........)
Forbidden That's all we know.

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#12
In reply to #10

Re: R&D Assistant Engine Bicycle

07/24/2014 2:48 AM

Post #8 is from you???? Please learn how to use CR4 correctly.....if you intended to post a picture or a diagram, it failed completely.

Its a "nothing-Post", wasn't worth even switching your PC on!!! Take a look!!

http://cr4.globalspec.com/thread/96876?frmtrk=cr4sd#comment1033246

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#5

Re: R&D Assistant Engine Bicycle

07/21/2014 3:11 PM

Congratulations!

.

Two things came to mind when you were discussing reduction gearing.

.

The first thought was that a harmonic drive might be very well suited to this application.

.

The second thought was that taking advantage of the large diameter of the rear wheel, and the numerous position options for interacting with the rear time. The idea would be to drive the rear wheel with a drive wheel that could be eaily engaged and disengaged on a locking arm.

.

Something like a skate board wheel might make a good drive wheel being durable and gummy enough to drive a bike tire in most conditions if there is enough pressure .

.

A swing arm swinging the correct direction could also protect the motor from being pushed by the bike to excessive speeds, by simply folding away when the bike wheel pushed the drive wheel.

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#6

Re: R&D Assistant Engine Bicycle

07/22/2014 5:37 AM

What most people do is to have a fixed wheel cog on one side of the rear wheel for the engine drive (and engine braking of course on long hills) and the normal bike chain and gears on the other.

That way the pedals only move when you use your legs and its far less dangerous to the user that way.....

If you look carefully at some of the pictures in this website, you can see two chains, one for the engine and one for the pedals, even on a 1912 motorcycle:-

http://en.wikipedia.org/wiki/Moped

I hope this helps you further.....and an old moped frame and wheels may be a good progression for you....think safe!

Getting a leg jammed in the frame near to the pedals and a stuck throttle and you unconscious!) sounds like a good way to lose important parts of your body!!!

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#7

Re: R&D Assistant Engine Bicycle

07/22/2014 6:42 AM

Congratulations, young man. Keep your spirits high.

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