I wanted create a for a long time bike with gear box in the bottom bracket
as I Expanded a rim rear hub and built a custom coaster,
I could not have gear .... and I missed it!
I'm inspired by old bikes (1900), and tractor mower gearbox!
I used bike gears, plexiglass and machined parts
I put two weeks to get the idea and create plans
and about 2 months to realize the gearbox!
there are three speeds and axis drive and output are the same
the selection system is brass
plexiglass box is to see the mechanism
as I Expanded a rim rear hub and built a custom coaster,
I could not have gear .... and I missed it!
I'm inspired by old bikes (1900), and tractor mower gearbox!
I used bike gears, plexiglass and machined parts
I put two weeks to get the idea and create plans
and about 2 months to realize the gearbox!
there are three speeds and axis drive and output are the same
the selection system is brass
plexiglass box is to see the mechanism
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First I made plans and gear ratio
Plans were made to the scale to facilitate manufacturing and various tests of setting up
Plans were made to the scale to facilitate manufacturing and various tests of setting up
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This brings me some ideas to build a quadcycle :D.
You told that “I put two weeks to get the idea and create plans and about 2 months to realize the gearbox!”
I want to Design my own gearbox. So can you tell me which books help you to get the idea or information to make or design your gearbox?
Please please please help me!
I wants to make available the most interesting of my research:
system speed of tractor mower (pic 3)
bikes with the old gearbox in the bottom bracket, (pic 6-8-9)
a gearbox-chain (pic 5)
one shema gearbox compact bike that I colored (pic 4)
other system (pic 1-2)
mine is a mixture of all that
on the schema of the photo No. 7 there is a simple freewheel system
it did not suit me at first because speed we can not pedaling backwards .... therefore the coaster brake that was not possible!
otherwise it is a simple system realize!
And if I want to design my own gearbox what information do I need?
for example, a standart Crankset about 45 teeth
the sprocket wheel is about 15
I used the principle of:
A = 20 teeth on B = 10 teeth
axis speed equivalent, B will turn two times faster than A
after I did a lot of multiplication and division
the rest has to give you ideas, observe plenty of mechanism and keep only what can be used on your gearbox
So can you give me formulas that you use to make your gear box?
That would yield 4 ratios with no more chain or sprockets. simply make engagement from the brass selector ring to the output.
Nice project.
I have used the following page to find many calculators when designing my projects.
http://www.rbracing-rsr.com/calculations.htm
http://faz-voce-mesmo.blogspot.pt/2012/12/avancos-contra-o-cancro-sobrevivencia.html
In regards to your comment of needing gearing for a wide rear wheel, they have Internally geared rear hubs. They are expensive, but let you have an 4-speed or 8-speed with only a single rear sprocket.
Nuvinci: (these are crazy expensive, but rather "cool") http://www.youtube.com/watch?feature&v=IZoSnzvHADQ
Shimano: ("cheaper", but still much more expensive than regular sprockets) http://en.wikipedia.org/wiki/Shimano_Alfine
I know there are speed hubs but few have the coaster
they are very expensive but if I wanted this system is that I fell in love with the old bike gearbox in the crankset
http://de.fotoalbum.eu/images1/200811/68604/204539/00000013.JPG
http://de.fotoalbum.eu/images1/200811/68604/204539/00000010.JPG
My system is also expensive, heavier, less reliable than speed hub has but it is more class and it's mine!
For example, taking a speed hub and putting in a plexiglass box
I started thinking about this for custom system I build for my brother
another and put a derailleur shifter and hubs bike in a box
my gearbox is not the easiest or most reliable in the long term, I would have to heat treatment of the gears to be on the strength
(steels used are planned for!)
if you really want to launch you, I can give you ideas
Very nice job indeed ! Thanx for sharing ! …
I did buy an older tooth paste that still exists here (Email Diamant : the one with the toreo as an icon) and it works !…
-1st 12-23
-2nd 15-15
-3rd 17-13
output gear, 26-11
(number of teeth)
I was a little confused in step 3 when you mention the "finger" that slides. I think this is a wide, U-shaped bar: one end has holes to screw onto the brass shift slider, and the other has a square tab that locks into the grooves on the inside of each sprocket holder. Could you show a picture of this "finger"?