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

Step 1:

First I made plans and gear ratio

Plans were made to the scale to facilitate manufacturing and various tests of setting up
you are an ENGINEER . this is the only word i can say now
Beautiful work! Congratulations. <br>This brings me some ideas to build a quadcycle :D.
First congratulations for beautiful work. <br> <br>You told that &ldquo;I put two weeks to get the idea and create plans and about 2 months to realize the gearbox!&rdquo; <br> <br>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? <br> <br>Please please please help me!
I searched a lot on the internet but I have not found much information .... <br> <br>I wants to make available the most interesting of my research: <br> <br>system speed of tractor mower (pic 3) <br>bikes with the old gearbox in the bottom bracket, (pic 6-8-9) <br>a gearbox-chain (pic 5) <br>one shema gearbox compact bike that I colored (pic 4) <br>other system (pic 1-2) <br>mine is a mixture of all that <br> <br> <br>on the schema of the photo No. 7 there is a simple freewheel system <br>it did not suit me at first because speed we can not pedaling backwards .... therefore the coaster brake that was not possible! <br> <br>otherwise it is a simple system realize!
How do you calculate gear ratio, number of teeth in pinion, speed and torque etc? <br> <br>And if I want to design my own gearbox what information do I need?
for calculating gear ratios, it is not easy to explain with a translator .... <br> <br>for example, a standart Crankset about 45 teeth <br>the sprocket wheel is about 15 <br> <br>I used the principle of: <br> <br>A = 20 teeth on B = 10 teeth <br>axis speed equivalent, B will turn two times faster than A <br> <br>after I did a lot of multiplication and division <br> <br> <br> <br>the rest has to give you ideas, observe plenty of mechanism and keep only what can be used on your gearbox
You told me that &quot;it is not easy to explain with a translator .... &quot; <br> <br>So can you give me formulas that you use to make your gear box?
You can have a setting that simply connects the pedals to the output. <br> <br>That would yield 4 ratios with no more chain or sprockets. simply make engagement from the brass selector ring to the output. <br> <br>Nice project.
Wow! Really nice work! Very clean design. Your final project looks like a lot of fun to ride. <br> <br>I have used the following page to find many calculators when designing my projects. <br> <br>http://www.rbracing-rsr.com/calculations.htm
f&eacute;licitation pour ce montage
Two great concepts, the Gearbox, and the Bike, and went to my Blog. <br>http://faz-voce-mesmo.blogspot.pt/2012/12/avancos-contra-o-cancro-sobrevivencia.html
I believe with his shown skills he might be able to make a Nuvinci style gearbox for coaster system, after all it was invented by Leonardo Da Vinci so there should be no patent infringment, and if he did not seek to market it there should not be any conflicts at all.
Amazing project!
incredible! well done. i hope you win something for this!
Holy Balls, that's amazing. Do you do this professionally as a bike builder? <br> <br>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. <br> <br>Nuvinci: (these are crazy expensive, but rather &quot;cool&quot;) http://www.youtube.com/watch?feature&amp;v=IZoSnzvHADQ <br>Shimano: (&quot;cheaper&quot;, but still much more expensive than regular sprockets) http://en.wikipedia.org/wiki/Shimano_Alfine <br>
No, I work in industrial maintenance!<br> <br> I know there are speed hubs but few have the coaster<br> they are very expensive but if I wanted this system is that I fell in love with the old bike gearbox in the crankset<br> http://de.fotoalbum.eu/images1/200811/68604/204539/00000013.JPG<br> http://de.fotoalbum.eu/images1/200811/68604/204539/00000010.JPG<br> <br> <br> My system is also expensive, heavier, less reliable than speed hub has but it is more class and it's mine!
I agree, yours is very classy. I had never seen the old-style gearboxes, thank you for showing.
Totally awesome! You did a magnificent job, there. Excellent Job!
Good work!! it would be great to have a video with the gearbox working!!
Well done this is the most appealing instructable I have seen yet! I would love to know more about how the selector works. Excellent job! Well done!
Amazing GearBox and Bike!!! I like it build one of this..but..in my country is a little bit difficult but not impossible!!! Best Regards
wow. just ... wow. you have combined great style with great geekness.
Any chance someone could knock up some neater schematics for this, like in AutoCAD?
Im always looking for more ideas to incorporate into my tinkering... ill have to get up off my butt to actually build this trike now tho lol
You've created a work of art, mechanically and visually.
Wow! I love what you've done here, very impressive! Thanks for sharing it too.
Clearly a genius at work.
Amazing, looks professional!
Great work there, not too sure I understand it all but I am not the best at visualization...
reassures you it is not easy to understand for everyone, I have a twisted mind ...!
I Enjoy this idea and was wondering how i would have a gear change system on a custom tadpole trike i am attempting to build... With your gear box its possible to have a decent gear range in a compact design. Also its beautiful in orange!
there are plenty of other ways to make a gearbox that is beautiful! <br> <br>For example, taking a speed hub and putting in a plexiglass box <br>I started thinking about this for custom system I build for my brother <br> <br>another and put a derailleur shifter and hubs bike in a box <br> <br>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 <br>(steels used are planned for!) <br> <br>if you really want to launch you, I can give you ideas
looks great!! <br>
Mais c'est tr&egrave;s bien ce petit boulot ! &hellip; Merci !&hellip; ;D <br> <br>Very nice job indeed ! Thanx for sharing ! &hellip;&nbsp;
People I knew of many years ago, said they used tooth paste and soft cloth to polish the plastic with.
Yes you're right ! &hellip;&nbsp;They did that when I was a kid : it is because at the time (still now, may be) they used very fine marble dust (as fine, or even finer, as talcum powder). <br>I did buy an older tooth paste that still exists here (Email Diamant : the one with the toreo as an icon) and it works !&hellip;
Great idea, what are the gear ratios for each speed? Very nice work, it came out beautiful!
ratio are: <br>-1st 12-23 <br>-2nd 15-15 <br>-3rd 17-13 <br> <br>output gear, 26-11 <br> <br>(number of teeth)
This is amazing! I make bicycle frames myself but nothing as nice as yours. <br> <br>I was a little confused in step 3 when you mention the &quot;finger&quot; 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 &quot;finger&quot;?
I think you understand the system <br> <br>Here is a picture that illustrates the &quot;finger&quot; <br>the bolt allows the &quot;finger&quot; to be driven by the brass slider <br> <br>the spring allows the finger go up into the holes of the gears
Thanks. That's similar to what I though. The spring allows the finger to dip into the groove on the shaft if the next gear's pinion is not aligned, and it snaps into place when it does align. Is that right?
you've got it! <br>But not being very good at English, I managed to clearly explain <br> <br>for shifting, you must stop pedaling, engage the next gear and pedaling gently until that the gear is engaged <br> <br>there are brass washers between each gear, they can bring down the finger to avoid two speed is trained at the same time <br> <br>if there were not these washers, transmission break
photos of brass washers
Excellent design, engineering knowledge and creativity made ​​possible creations like this, especially the skill to publish &quot;in detail&quot; and the desire to share with the community make it worth our vote.
Very nice, you have my vote.
thanks :-)
beautiful bike! <br>thanks for sharing that fantastic gearbox with us

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