A Very Very Low Cost Electric Bike from Pakistan

[numberonebikeslover]

Dear All;
It is so nice to be back after my tools were locked down by my parents and no permission to work on any mechanical project due to an accident during my work. I hurt my eye with the sparks coming out from grinder. For few days I was in bed but luckily there was no major injury to the eye ‘thanks God’. I accept, it was my negligence; I was doing it without any glasses on. I took it for granted for a second and it happened. A request to all; what ever tools we use are far more powerful than our expectations. Please use safety measures first.

I couldn’t find enough resources to make another bike so I decided to convert the same to a recumbent bike. Following are the pictures:

On my first ride it was to my complete surprise that I couldn’t keep the balance. It almost felt like I’m just a kid who is riding a bicycle for the first time. I’m using a joint which is used in the car steering system so that I could bend the steering to my desired angle. What I presume that due to the ‘joint’ my hands can’t communicate with the wheel, the way it is supposed to do on a normal bicycle OR it may be due to the fact that entire weight of my body is on the rare wheel and on front wheel there is negligible weight. Please help me out here because I’m losing my will to work further. A failure after many days of work disappointed me a lot. And the fact that soon my vacation will be over.

Respectfully
Naeem

 

[torker]

Good Day ! Nice to hear from you again. If you haven't found it go to bentrideronline and find recycled recumbent for good recumbent knowledge. It may have to do with the amount of trail in the frontend. It is the difference between a line drawn through your headset to the ground and the actual contact patch of your tire. If it is too much the steering will "flop" Side to side and if too little it will make the steering very "twitchy" Both very hard to drive. Shoot for 1 to 2 inches for start. Also you have made a very high bottom bracket relative to the seat. Look at my link to my photobucket. It has a short wheelbase I built on the last page. I actually kept the geometry of the bike stock so it rides very easy. One was to change "trail if it is not close is to put a bend in the forks or change the diameter of the wheel. A larger wheel may be impossible but a smaller one might tell you something. It is hard to ride a high bottom bracket recumbent especially at low speed. You have to kick the pedals really hard the first time to get momentum and then get the other foot up fast . Once you get some speed they are much better. Get a good side on shot and maybe we can see where the trail is. Sorry so long here..

Here is the pic for you.

 

[TylerDurden]

Glad to hear you are not permanently injured. Stuff seems to happen the moment you forget to wear protection.

If there is any looseness in the steering joint, the bike will be very hard to control. You might consider control-rod as another method (common on recumbents).

Your other geometry changes may also make riding a new challenge: perhaps a diagram of your bike, showing the wheels and fork-angle will give ES members the opportunity to make suggestions.


EDIT: a side-shot (picture) as torker suggests will also be helpful.

 

[numberonebikeslover]

Thanks for such a prompt response;
This is a side shot, I hope this may help in solving my problem. The joint is not lose at all, I double checked it and is very responsive.

Thanks again for the time all of you took to respond to my query.

Sincerely
Naeem

 

[liveforphysics]

A single u-joint doesnt behave linearly with respect to degrees of rotation input to degrees of rotation output.

Normally a u-joint in steering linkage is always paired up with a second u-joint that is 90deg out of phase, and at the same angle, so the non linear effects cancel each other out.

In this case, it may be a weight placement issue, and/or chassis rigidity issues.

Also, recumbents feel a little akward to ride for me under the best situations, I think they take a bit to get used to riding.

 

[torker]

Recumbents do take a lot of getting used to. Plus you have the pedals pretty high. You have one of the most difficult designs to ride. Sorry. You may try to get your seatback a little more upright. This will help while learning. Also it looks like your legs are stretched out too much. You should have a little bend in your knees with the pedal fully extended. These two things will also move your body forward which may help.

Still hard to tell where the trail is, the front fork is turned a little in the pic. Can you get a closer shot of the front half of the bike. Maybe you can prop it up as straight as possible. Need to be able to draw an imaginary line through the top and bottom bearings of the headset and see where it hits the ground.

 

[numberonebikeslover]

Dear All;

I've tried to practice riding my bike and its like learning cycling from the very beginning. I'm enjoying it but i'm concerned about having the bike in high speeds. any way. here is a video how this steering system is working.

Thanks every one.

With great respect for those who responded.

Sincerely
Naeem

http://www.youtube.com/watch?v=oBo26LYWM_0

 

[torker]

Very nice video. I am not sure of what Luke = Live for Physics mentioned about the u-joint you are using but he may very well have something there. After watching the video it looks as though the steering is very responsive, maybe too much. I know on my recumbents it takes a really light touch on the handlebars and very small steering inputs. It is far too easy to tense up and oversteer. You might try strapping a pillow behind you to get forward a little and see if this helps. Also I notice that you have room for a larger or smaller tire on front. This is good and may help fine tune the handling. Hopefully you can "borrow " a wheel and try. Also I enlarged your picture and tried to check trail. It appears you may have very little making it "twitchy" but is hard to do with a pic. When you use a straight edge through the headset it should contact the ground ahead of the tire contact patch by approx. 1 to 2 inches.

 

[amberwolf]

Based on my experiments with CrazyBike2 and the little I got done on a previous 'bent Recycle, I'd say that the things mentioned already are probably most of the issues:

--All your weight is far above where it used to be. Before, about 1/3 or more of it was below the seat line, in your legs. Now, it is essentially all above the seat line. That's going to take getting used to, plus it makes the "pendulum effect" that you normally use to balance with much harder to use as you used to. Usually you'd use the seat as a fulcrum to lever your upper body weight side to side to cancel out imbalances while riding, but you can't do that with your legs out in front of you, so you have to move your whole body side to side, and you end up pushing against the handlebars in doing so, which can cause steering to be harder, too.


--All the weight is up high, so any "pendulum effect" moves you make for balance will have more effect than if you were down lower, so every little correction you try to make is usually more than you meant to.


--I can't tell for sure if it is or not, but if your steering is not 1:1 ratio, and linear, it takes a *lot* of getting used to. I deliberately did not use 1:1 on CrazyBike2, so that I would not have knee interference with my handlebars even when the wheel was fully right or left. I tried it both as <1 and >1 and both took just as much getting used to as originally learning to ride. Ended up with using less steering input for more steerign action. Essentially like having power steering in a car, but also is "twitchier", in that any little steering input from me is magnifiedby the steering ratio. And bumps causing the wheel to deflect/steer do not provide as much feedback to me so it takes time to learn to correct for those, too, on roads that are not completely smooth.


Once you get used to the differences in control inputs, it may be more comfortable to ride (although if it were me, I'd get rid of the saddle and extend the lawnchair-style seatback to give you a suspended sling seat as well as the seat-back you have now).

 

[Jeremy Harris]

Nice to see you back here, Naeem, I really like the way you manage to build bikes from what a lot of people would call junk. I'm also glad to hear that you didn't do any permanent damage to your eye - I've done something similar, ended up in hospital having eye surgery to get the grinder fragments out of my eye.............

As others have said, recumbents are less stable at low speed than upright bikes. I rode one for a few years and, although it was fast it was a bit of a handful to ride at low speeds.

Jeremy

 

[TylerDurden]

If it's easy, you could also try reversing the fork for a little more trail.

Edit: I can't say it will help much, but it might be worth a try.

 

[torker]

Also a larger tire will increase it as well. I hope I have that right. It has been a while since my last build.

 

[AussieJester]

The problem is quite obvious Naeem, you need to grow a big bushy beard, wear a funny lookin helmet (brightly colored of course) pull on some mismatched fluorescent lycra and stick a couple of flags on the bent and she should handle just right... Sorry mate couldnt resist, recumbent riders have a reputation for being a lil 'different' to most folk..(no offence intended to bent riders) ...Good too see your back sorry too hear about the eye injury Naeem, really MUST protect the eyes whenever using machinery/tools you only get one set
Wish i could provide more help on your problem unfortunately i don't have any experience with 'bents'... Hope you get it sorted sooner than later, it may just be like Luke has said, they are a lil more 'difficult' to ride.

Also, recumbents feel a little akward to ride for me under the best situations, I think they take a bit to get used to riding.

hehehe ::giggles like school girl:: Lukes ridden a recumbent, did it have a frock motor too buddy :lol:

KiM

 

[methods]

....due to an accident during my work. I hurt my eye with the sparks coming out from grinder.

I take a lot of risks in my work and in my life but one area where I never compromise is eye protection while grinding. I too have shot metal shavings into an eye and after a trip to the emergency room I swore to never take that risk again - and I dont. Glad you got to learn a lesson without losing your depth perception.

The bikes are looking good.

-methods

 

[wineboyrider]

pull on some mismatched fluorescent lycra and stick a couple of flags on the bent and she should handle just right... Sorry mate couldnt resist, recumbent riders have a reputation for being a lil 'different' to most folk.

That sounds almost like Amberwolf? :|

 

[Lessss]

[youtube]oBo26LYWM_0[/youtube]

 

[katou]

sounds to me like you're getting used to the recumbent feel. It shouldn't take more than a few hours to get it going. If it does, probably the problem is in steering linkage (ask Amberwolf has beautifully explained) or in geometry.

I'd get a bit more trail as TylerDurden suggests by reversing the fork. Recumbent + twitchy steep steering = much falling down and loss of confidence.

I had the same experience trying out a 2 wheel lowracer at a bike shop nearby. You do feel like a kid learning all over again. I almost fell over, at less than walking speed. Luckily for me, I didn't. No way could I afford that bike.

Don't give up dude, you've got more determination and perseverance in your little finger than I have in my whole hand. Keep at it.

Katou

 

[AussieJester]

Nice lil video there Naeem... as i said last post i am no recumbent expert, so this is only
my opinion. I think it needs more rake and trail on the front fork, imo... this will
make it less twitchy when you turn the bars. As is, have you found the steering
to be very responsive with the slightest movement? Also, how much time have
you spent on the bike in this configuration, it maybe as suggested by other members
simply a case of 'learning' to ride all over again?

The steering setup you explain you might convert to is i think, very similar
to the "King of re-purposing's" i.e E.S member Amberwolf's
'Crazy bike 2' Perhaps have a looksee at how AW has done it he is always
very keen to offer some advice too perhaps hit him up for some
'pointers' on workable angles, no doubt he has experimented
a lil to find the best setup.

Here's a lil humorous cartoon i have posted previous on E.S
might cheer you up as you try to get used to your 'new bike' Naeem

[youtube]8GWp2_-aogc[/youtube]

all the best mate...

KiM

 

[torker]

Naeem, Did you try another size front wheel or get any more practice riding? I hope you don't give up yet. Let us know what you try. Dave

 

[numberonebikeslover]

A comment posted on Youtube by a member drew my attention towards an aspect of handle bar; the comment is as follows:

0urGaia
1 day ago
I am not sure but write my thoughts....Most bicycles have stem from the steering column then have steering bar attached to the stem. Think the length of stem reduces steering ratio making it feel less twitchy (also like lever it increase force of rider). Also front of bicycle looks smidgen too high. If you have curved front forks it will lower front and also increase length of bicycle, might result better feel.

Handle bar in most bikes is a bit protruded outwards to make it less twitchy shown in the following diagram: I'm thinking about trying out this setup with my steering system.

Thank you everyone for your useful comments.

Respectfully Yours
Naeem

 

[numberonebikeslover]

Naeem, Did you try another size front wheel or get any more practice riding? I hope you don't give up yet. Let us know what you try. Dave

Thanks for your concern Dave, I'm not an easy quitter. After giving my self a little break i'm coming up with new ideas and innovative ways to solve my problem. It is a great festival these days we call it Eid. I was busy with so many guests and dinner parties and what not and what not.

Thanks again Brother.

Naeem

 

[John in CR]

Naeem,

Nice work on the U-joint steering. I understand that recumbents take some time getting accustomed to riding, but I think you have have a couple of issues making things more difficult for you.

1. Using a single u-joint the amount of wheel turn for a given amount of handlebar turn will vary. I'm not sure if the effect is great enough to make a big difference in feel, but it is definitely there. 2 u-joints in series rotated 90° to each other and bent at identical angles will eliminate the effect.

2. It's difficult to tell from the video, but it looks like you may have as much as 8-10cm of trail in your front end geometry. That's enough to feel unstable at very low speeds on an upright bike, so it may be really difficult for learning on a recumbent with its lower and more vertically concentrated center of gravity. An unstable upright bike is like a tightrope walker with a long pole to help balance, vs a recumbent with an unstable geometry being like on a tightrope without the long pole.

Once you get it all worked out and have your ebike running again, please take some video out riding the roads. I'm sure a lot of us want to see what Pakistan really is like, not what we see on TV. I know I'd like to see the real Pakistan from a determined ebiker's perspective.

John

 

[torker]

Also - repeating myself- Different size front wheels will change the trail and make a big difference how it rides. A very easy test to do. Good luck and +1 on the video.

 

[numberonebikeslover]

Dear All;

It is amazing to share with you that I've removed the double U joint and the steering assembly for the moment and put a normal handle bar and while riding i felt almost no problem. There is nothing like a recumbent (unknown) feel of ride. What I've concluded from it is that the steering ratio of U joint is not normal. Moreover I've also tried another (bigger) wheel with the U joint setup but it made it more difficult to ride. So, I'm thinking about putting a control-rod setup tomorrow and dismantle the U-joint setup.

Thanks a lot everyone. I'd love to post a video when I'm done with it.
A lot of thanks to: torker, TylerDurden, liveforphysics, amberwolf (whose response is full of Knowledge and experience), Jeremy Harris, AussieJester, methods
wineboyrider, Lessss, katou and John in CR and all those who watched and took to time to read the thread.

Respectfully
Naeem

 

[John in CR]

Hi Naeem,

The u-joint in your video is a single one, not double, and you have it at a fairly big angle. That results in a steering ratio that changes as you turn the handlebars. The larger the bend angle the larger this effect. If I'm thinking this through correctly, and someone please correct me if I'm wrong, I believe the orientation of the u-joint in your video is at it's most sensitive with the wheel straight. That means very close to straight where our wheel is most of the time, the front wheel will turn more than the input of handlebar turn, and that ratio will change to a negative one as you go to 90°.

If your u-joint isn't welded on, you might first try turning the U-joint 90° on the steering and handlebar shafts. That will give you the least sensitive steering ratio at dead center and the steering should be much better. It will result in an increasing turn ratio, so it might still feel strange, but it should be much better than what you feel with a greater than 1:1 steering ratio near dead center where all of your balancing input takes place.

If you really have no play in the u-joint steering, then a good answer is a 2nd u-joint. Then you'll get a 1:1 wheel turn to handlebar turn throughout the steering range, just like a regular bike.

John