Yes, I am refining one myself, with surprisingly good results.

I wanted to experiment with something very cheap. I started with bungee cords but it doesn't work, the feeling is not the same than real paddling. My current setup (no actual pics yet it is raining) is the red line with just one pulley. If your space is limited, I guess you can be closer to the pole by adding a ground pulley (green line).

You thus need a pulley at about 2 meters high, a rope, a broken paddle, a weight (I use a 5 l full water container). the Pulley should be fixed so that your wobbles do not transmit to the weight and make it oscillate.

The weight gives you an inertia which reproduces very well the actual paddling. The trick is to let the weight get down and stop and re-raise it with the "catch" motion of the paddle, this way you can develop a lot of force on the catch by making your "catch" movement as quick as you want.
I was toying with the idea of adding fluid dampening of the weight, maybe with some wings acting as air brakes, or something on the cord?

IanInca said..
As you say the weight dropping could do with being slowed a little. Nice idea!

Yes, Currently I must take care to consciously slow the weight when it reaches the top to avoid the cord becoming slack and the weight colliding with the pulley. Nothing serious, but it breaks the immersion as it is something you do not have to care for while paddling on the water. So something that would slow the weight as it comes close to the top.

I may try to see if some bungee tying the weight to the ground, and only acting on the top of the trajectory could provide this. Or some slack spring around the cord attached to the top bar. Or some brushes. Or...

colas said..

IanInca said..
As you say the weight dropping could do with being slowed a little. Nice idea!

Yes, Currently I must take care to consciously slow the weight when it reaches the top to avoid the cord becoming slack and the weight colliding with the pulley. Nothing serious, but it breaks the immersion as it is something you do not have to care for while paddling on the water. So something that would slow the weight as it comes close to the top.

I may try to see if some bungee tying the weight to the ground, and only acting on the top of the trajectory could provide this. Or some slack spring around the cord attached to the top bar. Or some brushes. Or...

... a very large tub of water. Let the container splash into it and it will simulate whitewater.

Play this whilst practicing,

.. and post a video (sped up of course).

On the other cheap methods I considered but not tried:

Buying a cheap round inflatable kid pool, and stand on a stool in the middle of it, and paddle:



Tying one bungee to the top and one to the bottom of the paddle:



Or finding a discarded ergometer and salvaging it
www.supboardermag.com/2015/07/03/build-your-own-sup-ergo-trainer-for-less-than-50/

FinsUp, I know you are joking but the dampening is needed for the upwards movement of the weight, so that you can apply full paddling force without launching it into orbit, but not the downwards part as it would then make the cord slack that can induce wobbles.

FinsUp said..
For all the gadgetry i reckon a small pool would be the way to go. Most realistic paddle hard or slow. But would need some sort of barrier in there to stop a vortex forming otherwise would definitely break something when swapping sides and suddenly pulling against the current.

Yes.
Maybe having 2 rectangular pools side by side and ride between them: a vortex in each pool.

The good exercise machines (bike, elliptical, rowing) provide some inertia (you rotate a heavy flywheel) and a fluid dampening, often via inducing electrical currents in a moving magnetic field, like a bike dynamo, as having actual water in them is not practical. Cheaper ones use a flywheel + friction by applying tension on the belt.

I was thinking of using a bike dynamo - or any DC electric motor - as a pulley, or attached to the pulley.

colas said..
I may try to see if some bungee tying the weight to the ground, and only acting on the top of the trajectory could provide this.

Well, after some experimenting, this seems to work quite well, it was exactly what was missing.

This way you do not have to control yourself to not hit the pulley, and the bungee sends back down the weight full force, so you can sustain a faster paddling frequency, close to an actual sprint on the water, and it adds force to the "catch" phase, so you get more tired per exercise time, which is the goal.

I have my phone playing rock playlists beside me, and paddle on one side during a full song and switch for the following one, but barely with a 5kg weight, I could not use an heavier one.

The bungee cord length should be so that when fully extended it just prevents the weight to hit the pulley. On my setup it is slack until the weight is about half way up.
I tried with a broken surf leash, to gets some dampening, but they are not stretchy enough (even the 5mm ones) and stops the weight too brutally.

I made a kind of harness with strings around the container so that I can attach the bungee to the bottom of it so that cord and bungee are aligned when in tension.

I will keep experimenting a bit more to tweak things. I am going to buy 5kg exercise weights (less than 20 euros) to replace the container so that it is less bulky and gain a bit more range of movement. I will make a video once I feel I have the final design.

I use it outdoors, attached to a clothesline pole, but I guess it could be adapted for indoor use.

Note: the pulley is actually a spare roller for sliding gates, they are designed for outdoor use and are quite robust. I use a 1cm wide cord in it so that the cord is too big to get derailed.

Current state:

Here is the video:



details:
I used four 1.25kg weights, on a wood bar, with the dyneema cord going through a hole in it. I also include a pic of my rope harness around the water container.

great design colas

I have to say I have been in discussion with Colas lately about this but more related to the issie of balance.

His idea above is EXCELLENT. It has served the purpose of seeing how I can transpose this idea into a gym environment since you already have the weighted pulley system in place.

I think what you could also migrate to is the inclusion of a Bosu ball whereby you practice the art of paddling on an unstable surface.

Just to add I have found doing exercises like pull ups, seated rows to be extremely helpful in so far as building up paddling strength if done correctly.

Well done Colas!

Some enhancements after some use:

- the bungee cord has broken, I guess it is the part that wears the most. From time to time I added a knot to shorten it a bit, but I have now doubled it by an old leash cord. The leash alone is not a good solution, as it is loose most of the time, and it induces shocks by alternating being slack & tight. But as a safety to prevent the bungee to go to max length, it may prove useful, and it adds to the intensity of the training.

- Some foam at the bottom of the paddle is welcome. I have hit myself in the shins a number of times, trying to vary the position (squatting or stretch-fencing on the pull), or mind-wandering.

- I have a spotify playlist where I gather all the upbeat musics I find, for use later in my videos and for amping up driving to the beach. I have copy-pasted a big set of them of similar duration (~3'30") into a "training" playlist, that I play in shuffle mode on my phone while training, changing sides between songs. I keep the number of "sets" (two sides) done with this homemade counting disk :-)

Hello Colas,
Just a quick question, if you do not have the benefit of the lower pulley, would the distribution of forces be closer to paddling on the water if the attach point on the shaft was sligthly above/underthe lower hand rather than at the end? Never tried something like that, just curious.

Thank you

colas said..
Some good ideas by Starboard Team rider Leonard Nika. A setup similar to mine, plus more other exercises:

great video mate stay safe and keep the videos coming
I underwent neck surgery on the 18th March so currently in recovery and it will be 6weeks until i can start paddling again your videos will keep me motivated until then thanks :)

More tweaks to my system. 30mn daily for weeks now provided me good feedback on what works. (plus first time I get under 95kg in decades!)

- The leash broke at the 3nd session at the junction to the rail saver, I just made a simple knots and it have been holding great. It guess this system could be used for stress testing leases :-), and also it shows why you may want to rely more on knots in big waves (like XM does) than standard ways to connect the cord to the rail saver or cuff. The leash seems to really saves a lot of wear on the bungee, definitively worth it.

- it is a good system to test which paddle grip works. My choice of tropical Mrs Palmer wax works great.

- the lower carabiner moves alot, I thus tied the bungee & leash tight to a manilla so that the only friction is metal to metal. Also I tied in place the cord to the carabiner with loops of cord (black on the pic) with a drop of glue on the knot so that the cord does not move.


My stand for my phone for the music, and the wheel to keep track of the series#