He encontrado un par de patentes de bicis que se parecen a la marianette:

US4147370
US598026
US628426

Cambie el plato por uno de 54 dientes, ahora se puede remar cuando se va deprisa.

Some people asked me where I found inspiration for the “marianette”. Here is a link with most of the known rowing bicycles: http://www.rolllinks.info/page6.php

I would only consider these bikes for commuting: http://www.row-bicycle.com/ , http://www.superider.com/index.htm, and http://www.ruder-rad.de/ .

Only the ruder-rad is currently commercialized in Europe, but I didn’t want to spend 2799 €.

Ruder-rad and superrider use crank mechanisms which are a bit too complicate to copy. The ruder-rad uses an additional wheel and transmits the movement to the rear wheel through the bottom bracket in which a free wheel is adapted. Connexion between the crank mechanism and the stem is also a bit complicated. In the superrider the stem construction and the weighted flywheel appear too complicated to me. La “marianette” uses standard bicycle parts, allows to row only if wished and has gears in the front wheel.

Esta semana he ido cada día al trabajo con la marianette. Va estupenda, se suben las cuestas mejor. La gente solo se sorprende cuando remo, sino la mayoría ni se fijan. Algunos colegas se han interesado. Los amigos que han probado la bici la conducen bastante fácilmente, excepto los que no están acostumbrados al freno a retropedalada.

El plato es demasiado pequeño para remar cuando la bici va rápido. Me he comprado un plato más grande, lo probaré este fin de semana.

Otra mejora posible es cambiar el elástico por unos muelles, aunque el elástico va bien. El elástico devuelve la energía de tensarse cuando se destensa, sospecho que los muelles tendrán menos perdidas.

Para más adelante puedo probar un plato ovalado (como el de la firma Rotor) para aumentar la fuerza al acercarse a los puntos muertos. Otra cosa a probar es descentrar el plato, con lo que puedo hacer más fuerza en una parte del recorrido. El manillar también lo quiero cambiar para tener mas posiciones. Ya veré después de las vacaciones. Puede que tenga otras ideas, hay bastantes comentarios en instructables.com.

La "marianette" es una bici a remo que me he bricolado recientemente.

Monto el blog este para ir guardando su evolución y recoger sugerencias o comentarios.

La explicación que sigue esta en ingles porque la he preparado para http://www.instructables.com/id/Row-pull-push-bike-la-marianette/ , ya la traduciré si a alguien le interesa. Se admiten comentarios en cualquier idioma, se contestarán como se pueda.

Row pull-push-bike

Here is how I build a simple rowing bicycle with a child’s bicycle and a folding bike.

Several rowing bicycles are available aiming to improve upper body training. However, they are expensive, it is difficult to find local distributors and most of them are not really suitable for everyday use. This one is cheap, easy to drive and fulfils all traffic regulations that I’m aware of.

Instructions:

Find suitable bikes, in my case a folding bike and a child's bike:

Cut the rear of the child’s bike and mount it as a front wheel in the folding bike using the method of http://www.instructables.com/id/Front-Wheel-Drive-Center-Steer-Semi-Recumbent-Bicy/
To make place for the rear hub in the front fork, you may deform it using a dismounted hub as in the picture:

My folding bike (like most) has a hinge to fold the stem. If your bike doesn’t, then cut the stem and fix a suitable hinge.

Fix a pedal on the stem or handlebar and link a bar from that pedal to one of the front pedals. You will have a crank mechanism: http://en.wikipedia.org/wiki/Crank_(mechanism)

I used a short crank with a crank shortener in order to make shorter rowing strokes:

Crank shorteners are sold in pairs. I used the second crank shortener and the saddle support of the child bicycle to fix the pedal to the stem.

It is difficult to pass the two dead centres of the crank, so I add an elastic rope to help. It would also be possible to freewheel while pushing and use only the pull motion, like rowers do.

Then you have a pushbike in which you can really push while riding:

I hope you like it.

Mariano 30.07.2011