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1593244 No.1593244 [Reply] [Original] [archived.moe]

First time poster looking for some advice. I want to make a rowing bicycle.
I was inspired by this german engineers attempt www.rowcycle.de, but it's
not for sale yet and they say it will be priced in the mid 4-digits -
way outside of my budget. This american version rowbike.com looks way less
complicated but also not very interesting.
I plan to make it mostly out of recycled bits to save on cost. I've got
some understanding of mechanics but no real engineering experience.
I've got basic tools and can get used bicycles for next to nothing.
Looking for ideas and technical help to make a rowing bicycle.
Some of the things I expect to be difficult are:

1) Converting pulling motion into rotational motion.
2) Having the pulling handle return to starting point without creating too
much resistance that doesn't convert to rotational motion.
3) Decoupling wheel motion from pulling device when not actively pulling
4) Converting leaning to the side to turning/slanting of the front wheels

Where do you suggest I start? I was thinking of building a frame first that
cannot turn to the side, just to focus on conversion of rowing to rotation
and once that is sorted, begin working on turning.
So first a frame with 3 wheels, a sliding seat and a pulley connected to the
back wheel.
Anyone want to build one with me and share ideas?

>> No.1593248


>> No.1593256

Is there some advantage of rowcycles?
Sounds like you want to put lot of strain on your upper body. That's the way of getting heart attacks, if you don't know what are you doing.

>> No.1593260

I'm guessing a normal bike is more efficient, but this seems more fun and works different muscles including upper body.
I don't see why performing a rowing motion would induce a heart attack.

>> No.1593263

>That's the way of getting heart attacks
>t. fat ass.

Controlling a row bike steering wise is going to be a nightmare. I could see it done several ways.
You could have your feet do it with two pedals instead of having a fixed position.
You could do it via leaning, but good luck doing a tight turn. Also what the fuck are you going to do to reverse? Use your feet on the ground?
3rd way is having two cables on the row handle each done driving a wheel at the front. If you pull more on the left side it would turn you right.
4th way is a steering wheel with a sliding mechanism for the pull mechanism. This one you'd have the most steering but would definitely add friction to the pulls. It would consist of a tube inside a tube with slots in the outer tube and bolts/pins connected to the inner tube to slide in the slots. Turn just like a steering wheel. Have pull cable connected to wheel.
What are you going to do to brake, a hand brake lever?

>> No.1593271
File: 36 KB, 1604x775, Rocykel.png [View same] [iqdb] [saucenao] [google] [report]

I came up with a rough idea for the motion generation. Steering is trickier.

I'd like to go with the leaning if it can be done right.
> but good luck doing a tight turn
Leaning more increases turning?
>You could have your feet do it with two pedals instead of having a fixed position.
This is a good idea as well but power from pulling is transmitted through the feet so I'd have to be careful not to push more on one side.

Breaking I would probably do with foot pedals. Heels for bracing against the force of pulling and front foot for breaking.

Advice and suggestions welcome of course

>> No.1593272

Små hjul m rende=pulley thingy
The jewish stars in the wheel are gears
cykelkæde=bike chain

>> No.1593276

>Breaking I would probably do with foot pedals. Heels for bracing against the force of pulling and front foot for breaking
Having to keep ankles locked and the pressure on your heel is going to fuck up your legs, if anything put the break on the heel, but even that is going to keep you from using your entire leg when pulling and you will not get much power in your breaking. Just mount break levers on the bars, simple, effective, does not effect your stroke.

I would steer with oars.

>> No.1593281

If I mount break levers on the bars I'll have 1,5m/5foot plastic tubes with brake wires inside flailing around

>> No.1593286

cables are not difficult to secure.

Just try rowing like that for any amount of time and see what your legs think. If you row in a boat with a fixed foot brace you will naturally rock through the foot, start on the balls and end on the heels. In rowing machines and high performance rowing shells they have pivoting foot braces so you can keep the pressure on the entire foot yet still roll through the ankle so you use your entire leg.

Your plan will concentrate the work to just the front or back of the lower leg and put a great deal of strain on your ankles.

>> No.1593289

Thanks man. I don't have much rowing experience, so this kind of info is very useful. I'll have to find a way to attach the cables so they can extend as I pull the handle but tuck away as the handle goes back in.

If you had a look at the "blueprint", I'm bothered by the spring at the bottom will drain energy but not provide motion. Any ideas on how to do it differently?

>> No.1593291

>Leaning more increases turning?
Yes, but it's not going to be like a bicycle. You have two wheels in the front that don't actuate. It will want to keep the vehicle moving forward instead of turning. You also have to understand your not going to get the same speeds as a motorcycle, you won't have the centrifugal force keeping you in the seat when turning, you're going to fall off if you lean too much. If you're trying to turn from a stop, it just won't be able to get a small enough turning radius.
Let's say your on a street and you want to turn left from a stop, you'll need large lean but won't have anything keeping you in your seat.

>> No.1593293

I'd say have two pulls. Each one acting on one of the front wheels. Have one in each hand. Want to do a sharp turn, just pull with your left to turn right. It would also mimic a real rowing situation because that's how they steer.

>> No.1593297

In the video of the row bike, they have a mechanism to actuate the wheels. You won't be able to just lean to steer unless you have a similar system to actuate the front wheels. Also not once did they do a from a stop turn. It most likely is hard as fuck to do.

>> No.1593305

that would be a scull-bike, not a row-bike

>> No.1593324

OK, then you need to actuate the front wheels then.

>> No.1593349

Upper body workouts are more taxing than lower body workout. You should know that if you hit a gym.

>> No.1593666

Scull and row are the same, they both can mean the act of rowing or the implement, the oar, the only real difference is scull can also be to propel oneself with a single oar over the transom.

Do a search for converting rectilinear motion to rotary motion, there are a great many mechanisms out there for doing this, that should give you a great many options.

>> No.1593667

Rowing is mostly legs, you'd know that if you hit a gym and then did something in it.

>> No.1593700

For the spring, it is simple and would work, the spring only has to overcome the force of the freehub and be strong enough to support the excess chain, so not very strong. The addition of a jockey wheel to support the chain and something to support the spring means the spring only has to be strong enough to overcome the friction in the system before the next stroke starts, not that strong at all. I have a few alternatives, I will post em when I get some time tonight or tomorrow, as well as some cable routing shit, if someone else does not beat me to it

>> No.1594023
File: 12 KB, 571x388, brakes.jpg [View same] [iqdb] [saucenao] [google] [report]

If you want break with your feet why not make the breaking pedals separate from the "fixed position pedals" where you rest your feet while pulling. like pic related

For the steering you could also use the breaks if you make it so that each foot breaks only on one side. It would not be energy eficient and if you need to steer while standing still i dont know how that would work. just a bad idea probably

>> No.1594041

>That's the way of getting heart attacks

The original Concept rowing machines rotated a bicycle wheel on the frame. The original plans are fairly easy to find.

>> No.1594174

Thanks for proving my point.

>> No.1594184

OP here
I feel like one wheel in the front and one in the back will be two hard to
balance. So three wheels total, but -
Two wheels in front or two in the back?

To avoid the need for a differential, i think it's best to have the driving
force on the single wheel end. What are advantages/disadvantages to having
the propulsion wheel in the front vs back?

Do you mean a jockey wheel just to hold the chain up against the gear wheel?

That could work, good idea with the brakes.

Can you tell me what to search for, I can't find it

>> No.1594197
File: 116 KB, 495x560, 1392845994868.png [View same] [iqdb] [saucenao] [google] [report]


>> No.1594198

I guess the propulsion wheel should be the one that has most of the weight of your body+the bike on it for better traction.
But it would also be good if most of the weight rests on the side with 2 wheels. So thats a bit of a dilemma.
2 wheels in the back would definetly look better imo.

>> No.1594207

Concept2 model A. Someone either on here or on /fit/ built one a couple of years ago, all you really need is a way to retract the cable and something like a normal geared bike mechanism that only transfers torque one way. It's not the same design obv but there is common ground



>> No.1594472

>2) Having the pulling handle return to starting point without creating too
much resistance that doesn't convert to rotational motion.
Why not use a torsion spring? They're compact and do exactly what you want.
>3) Decoupling wheel motion from pulling device when not actively pulling
Use a sprag bearing. They are available cheaply online.

>To avoid the need for a differential, i think it's best to have the driving
force on the single wheel end. What are advantages/disadvantages to having
the propulsion wheel in the front vs back?
I'd say you're right about avoiding the differential by using a single drive wheel. In my opinion you should use a rear wheel drive set up, front wheel steering, and brakes that are either rear only or heavily biased to the rear. Also, the brakes should be applied by a hand lever positioned next to your dominant hand. Lastly, regarding your steering system, you would be best served by a foot pedal operated system. My first thought is that you should have a pedal arrangement such that you can steer with either foot while bracing with the other.

>> No.1595455

Row back for reverse

>> No.1595488


>> No.1595501

This is a terrible personal vehicle.
I'm going to suggest something you may not like, but it's the best use for it.
Make it a two person vehicle.
One powers up the beast, the other steers.
Alternatively, no steering and no reverse.
Climb uphill with the power of the upper body

>> No.1595536

It is a terrible personal vehicle but it is a good way to get some miles in if you can travel around in it (you wouldn't be able to most places). The main issue is that you're so low down and in most places you'd be expected to ride that thing on a road with automobiles, so scary shit and also fun inhaling exhaust fumes. Not impossible but not great.

The steering is not the problem really, people doing sculls steer with a foot mechanism in the boat so it's a bit of practice in a way, easy enough to set something up. Also while rowing is more upperbody than cycling, it's still very leg dominated.

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