CVT like setup using Chains&Gears

[numberonebikeslover]

Hello Every Body!

After having my e-bike breaking driving chains I thought of putting the gear shifting mechanism where there is lesser torque. So, here it is. It is almost like a CVT using Chains and Gears. There is one more thing in this setup; one would only need one throttle (for gear changing/shifting) and the variation would be greater. It would enable the rider to climb the toughest hill and in downhill use the maximum increase in the gearing ratio for speed. It would also enable the rider to use the maximum available power very efficiently.

One flaw I’ve thought of a way to overcome; in a situation when throttle is reversed the changer shifts the chain on rare gear back to the smallest gear but there is nothing to shift the chain on the front freewheel (which fixed to hub and is in inverted position) I’ll do a modification which I will share later on. I wish I had a day of more than 24 hours so I could do so many things that I’m unable to do after office. Wish me luck guys.

Your precious feedback will be highly appreciated.

Sincerely
Naeem

[Miles]

Good idea, Naeem.

Have you seen this document (originally posted here by boostjuice)? http://iris.lib.neu.edu/cgi/viewcontent ... g_capstone

[amberwolf]

That's pretty much what I wanted to do on CrazyBike2 but never actually sat down to work it out.

Shifting the front cassette is one of the problems that kept me from trying it. I'm definitely interested in seeing how you do it!

[numberonebikeslover]

I'm definitely interested in seeing how you do it!

As both the shafts are quit near to each othere this gives me the option to used the movement of the rare shifter to co-ordinate and shift the front with some mechanical upgradations. but i'm not sure how workful is this to be given a try. You also try to figure out in the light of my setup and the idea that i shared now.

thank you

Naeem

[12p3phPMDC]

Hello Every Body!

After having my e-bike breaking driving chains I thought of putting the gear shifting mechanism where there is lesser torque.

I put a 3 speed hub in a similar arrangement for the same reason, to reduce the torque on the transmission.
We have the same drivetrain layout almost exactly Yea, there are differences, like you have a chain input, whereas, mine is a belt.
You have a cassette-based transmission where I have a 3 speed hub. But the shifting takes place on the same side, and they are
both left-side drives.

The three speed hub is not being used as static and dynamic weight bearing axle in a wheel, which should take the strain and some shock loads off the sun gear that is on the axle..

Hopefully you break less chains with your setup...

So, here it is. It is almost like a CVT using Chains and Gears. There is one more thing in this setup; one would only need one throttle (for gear changing/shifting) and the variation would be greater. It would enable the rider to climb the toughest hill and in downhill use the maximum increase in the gearing ratio for speed. It would also enable the rider to use the maximum available power very efficiently.

Your setup will have a large range of gearing Naeem!!!

What are the cassette sizes?

By my best estimate.....
Lowest Reduction: 12:30, 0.4
Largest Step Up: 30:12, 2.5
That's a range of 625%.! more than a Rohloff @ 525%
Range of Input Cassette
12:30?
Output Range
~30:12?


I look forward to seeing how you will shift the front cassette.

One flaw I’ve thought of a way to overcome; in a situation when throttle is reversed the changer shifts the chain on rare gear back to the smallest gear but there is nothing to shift the chain on the front freewheel (which fixed to hub and is in inverted position) I’ll do a modification which I will share later on. I wish I had a day of more than 24 hours so I could do so many things that I’m unable to do after office. Wish me luck guys.

Your precious feedback will be highly appreciated.

Sincerely
Naeem

Chris

[Grinhill]

Hi Naeem

I spent a bit of time thinking about this very same design a few weeks back, I really like the Phaser derailleur-in-a-box transmission and other similar ones.

My suggestion is to unhook the S-shape that the chain goes through, then bend the tensioner upwards towards the upper leg of the chain. Then hook the upper leg of the chain back on the tensionser.

I hope this sketch explains my idea:

derailleur_sketch.jpg (27.87 KiB) Viewed 1344 times

So, the tensioner will now be squeezing the upper and lower legs of the chain together, thus maintaining tension. This puts the idler pulley in a good position to shift the front cluster.

The tensioner spring may not allow the tensioner to lift up high enough, as it will have to rotate an extra 90 degrees or more. It might be necessary to mount the derailler forward or up a little, instead of its usual mounting point directly on the axle.

I'd love to see if this can work in practise.

[Miles]

So, the tensioner will now be squeezing the upper and lower legs of the chain together, thus maintaining tension. This puts the idler pulley in a good position to shift the front cluster.

Hi Grinhill,
Interesting idea but I think the problem with this is: 1. That the dynamic tension will be working in opposition to the spring.. 2. Running the chain around a jockey pulley on the loaded side of the chain is much less efficient than on the unloaded side.

[Grinhill]

Thanks Miles, I see your point. So that's why the design of a front derailleur is different.

Perhaps a front derailleur could still be "frankensteined" on top of the rear deraileur, provided the two axles are close enough together (as they are in the phaser-style gearboxes).

[Miles]

Yes, the rear dérailleur tensions the chain and does the shifting. All the front one has to do is shift, so the loaded side of the chain isn't compromised. On some of the early dérailleurs, the tensioning was done by a separate lever arm at the front (no front dérailleur).

You just need to get lateral guides on the loaded side of the chain, for the front set.

[numberonebikeslover]

Dear All;

Thank you very much for such nice and precious suggessions.
I've made a setup of front derailer/shifter (shown in the follwoing figure) made out of door locking machinisms I found in the junk.

Front Shifter Mechanism

Front shifter1.JPG (95.17 KiB) Viewed 1233 times

It will take its movement from the rare derailer at the point mentioned in the next picture with an arrow pointing the specific point where the movement is to-and-fro and thats what the front one needs for shifting the front chain.

Point where the front shifter will take movement from the rare shifter

rare shifterpoint of contact.jpg (22.76 KiB) Viewed 1232 times

[numberonebikeslover]

I put a 3 speed hub in a similar arrangement for the same reason, to reduce the torque on the transmission.
We have the same drivetrain layout almost exactly Yea, there are differences, like you have a chain input, whereas, mine is a belt.
You have a cassette-based transmission where I have a 3 speed hub. But the shifting takes place on the same side, and they are
both left-side drives.

My Dear Brother:
thank you for your feedback. Could you be kind enough showing me a picture/video of your setup; call it my ignorance that i'm unable to figure out what you have said in the afore-cited para.

Your setup will have a large range of gearing Naeem!!!

What are the cassette sizes?

By my best estimate.....
Lowest Reduction: 12:30, 0.4
Largest Step Up: 30:12, 2.5
That's a range of 625%.! more than a Rohloff @ 525%
Range of Input Cassette
12:30?
Output Range
~30:12?

My cassette/freewheel is of seven gears on it starting with 14 tooth, 16, 18, 20, 22, 24, 28. I've calculated it and it shows that it gives me a ratio (between both driving shafts) of:
1) 1:2
2) 1:1.5
3) 1:1.2
4) 1:1
5) 1.2:1
6) 1.5:1
7) 2:1
This is quite a wide rage of change in the gearing ratio indeed, enabling me to climb the toughest of hill.
Wish me luck bro.
Naeem

[def215]

wow. the front deraileur setup is just spectacular!

so would the front and rear deraileur move at the same time together, or are they moved independently? anyways, good luck with this project and i hope to see it on something in the near future. stuff like this just blows my mind.

[numberonebikeslover]

so would the front and rear deraileur move at the same time together,

Yes sir, both will move in the same time in coordination with eachother.

Thank you for appreciation. I'm of the same view, I enjoy such creations and always search and browse internet for the same stuff.

[numberonebikeslover]

Dear All;

At last it is a success. It works very accurately, beyond my expectations. though it is not permanent setup, i will improve it further to make it faultless and perfect. i'm sure i will come-up with ideas.

I only had to disable the up and down movement of the S shaped derailer (shown in the figure with an arrow) by a small weld.

[Grinhill]

Well done, man!

At the moment, it looks like only a single piece of heavy wire connecting the front & rear derailleurs. I'm guessing you will strengthen this?

I'm also wondering if your front derailleur could have the opening "flared" a bit, rather than have each link striking a sharp edge?

[numberonebikeslover]

At the moment, it looks like only a single piece of heavy wire connecting the front & rear derailleurs. I'm guessing you will strengthen this?

Definately; I would strengthen it so that it can withstand any stress or strain and it should be longlasting. At the time i had nothing, everything was happening in my mind (imagination) so i used nails with tough metal.

I'm also wondering if your front derailleur could have the opening "flared" a bit, rather than have each link striking a sharp edge?

The follwoing figure explains how the chain is held between the front derailer's bracket and the chain links can't get stuck rather slip through.

[numberonebikeslover]

Dear All;

Following link will tell the reason for my absence from ES.

http://www.youtube.com/watch?v=VpWcQ-ovgP0

This is a variable transmission with a very vide range of choice, using simple chains and gears readily available in the market in my city ( Peshawar , Pakistan ). It is not just a final stuff at the moment but I’m working towards perfection.



I thank you all for nice comments and appreciation which is indeed great source of motivation for people like my self out there in the world trying to serve humanity and play their part in this world, positively.

[liveforphysics]

Outstanding! I loved your video, and it was very clever how you built the rigid guide for the top chain to move with the derailer.

Your english is very good!

I always love to see your work.

Much respect to you Naeem.

-Luke

[Miles]

Well thought out and nicely implemented Naeem!

[amberwolf]

This is a variable transmission with a very vide range of choice, using simple chains and gears readily available in the market in my city ( Peshawar , Pakistan ). It is not just a final stuff at the moment but I’m working towards perfection.

Nice. Where does the pedal chain hook in? (looks like it is not yet integrated?)

[Solcar]

I really like it, Naeem!

[numberonebikeslover]

Where does the pedal chain hook in? (looks like it is not yet integrated?)

Yes Sir, you are right it is not yet hooked in but this time i'm going to put it right above the front tire and my seating position will be like sitting and leaning a little so is going to be the position of the handles but i've not figured it out yet. this is what i'm planing. It just to make the bike more aero dynamic. Do need your precious word on it though.

Looking forward for suggessions and coments.

Naeem

[amberwolf]

What you are planning sounds like what is commonly called a Short WheelBase (SWB) recumbent, with the seat position being high up also sometimes called a Highracer. Those terms may help you search out more information on how others have done this easily enough.

If you look in the older parts of my Electricle blog, you'll find the ReCycle, which was a Lowracer but still with pedals over the wheel to keep it from being quite as long as it otherwise would be (like CrazyBike2 is). There's some stuff about how I started to work out a folding boom for the pedals, extendable so I could adjust it for my leg length.

One thing to note is that on a normal-height bike, being seated leaning back a bit with your legs up at or above the level of your hips is going to be a much higher center of gravity (COG) and will take some time to learn to ride it. Having the electric to help you start up will be a tremendous advantage, as otherwise it can be difficult to get such a bike started from a stop, as you cannot just stand on the pedals to do it as on a regular bike (as yours was before).

This is one of the main reasons I built CrazyBike2 in the compromise position of forward but low-down pedals, and a semi-recumbent seat farther back partly over the wheel, with a much longer forward section to ensure the tire cleared my toes during pedalling and turning. The whole bike is more stable at startups than if I had my feet up high over the wheel, though it has a significantly larger turning radius at a reduced turning speed.

It also required using "remote steering", as the handlebars' steering point was now going to be so far forward as to require handlebars over two feet back from that point; impractical and uncomfortable to use. Remote steering lets me use normal bars and comfortable usage, and also lets me change the ratio of handlebar movement to steering movement, which you can't do if they're directly attached like a normal bike.


So if you are able/willing to significantly stretch the bike frame, you could go something along the CrazyBike2 design, or other similar ones out there. If you prefer the short wheelbase (SWB) of your regular bike, there are many models to emulate of that type, with many solutions to get the chain back from the pedals to the rear wheel.

There are even solutions to run the chain to the *front* wheel, so you could have it be entirely independent drivetrain from the motor, if you choose.

[12p3phPMDC]

Naeem,

I just saw a horrible video of a bombing in Peshawar on the news tonight. I pray and hope that you are OK and am sorry for those that
may have been hurt.
I know you have mentioned terrible events like this before, but after seeing it on TV, It hit home because of what you have shared
with us on Endless Sphere.

But your positive attitude, excitement, and motivation are inspirational Naeem!
Thank you for your video. and Good job and good luck with your bike!

May God bless you Naeem.

125px-Flag_of_Pakistan_svg.png (1.98 KiB) Viewed 307 times

Here is the link you asked for in the earlier post.
viewtopic.php?f=28&t=9339&hilit=catrike+three+speed&start=30