Adding an additional hand crank?

[xjcampx]

I started riding my Sofrider hands-free to relax my shoulders and now I very rarely hold the bars. Today it occurred to me that it wouldn't take very much to add a second [hand] crank to the front triangle. Has anyone ever experimented with this type of configuration or know of anyone that has???

The idea of adding weight to the front end is not appealing but it seems like the advantage of incorporating the upper body muscles might make it worth trying.

 

[ak-tux]

I think you are bordering on

I think you are bordering on a custom modification. Try to look around or post a question on http://www.bentrideronline.com/messageboard/forumdisplay.php?f=11

You may end up with something like this:

alt="Hand-foot FWD-MBB"

 

[John Tolhurst]

grab the bars and apply a bit more grunt

If you want to use your arms to create more power and lift your heart rate, grab the bars and apply a bit more grunt. Easier than adopting a new engineering problem.

 

[ak-tux]

Yes, and  although you could

Yes, and although you could use both arms and legs at the same time with the hand crank, you probably may note neccesssarily generate more power due to the coordination it will require and the added drivetrain complexity alt="indecision"

 

[psychling]

Not to mention balance

Not to mention balance issues.

 

[loveoption9]

Early experienc with hand and foot design

Hi All,
I spent way too much time in the 80's trying to build hand and foot powered front wheel drive bikes. The first bike I built was a four bar linkage which worked very well, but the cadence was slow and it had massive amount of torque and no speed. Great for exercise, not for speed. I also build a hand only powered bike which worked very well. I think the only person who has built and raced a hand and foot powered bike is Fred Tach, who won the HPV road race around 1980 with his aptly named manuped. Ironically, we crossed pathes at the 2011 Oregon Manifest cargo bike competition. He had the same bike! To this day, no one but Fred can ride it. The clocking of the cranks hand and foot and the steering torque is very complex. After that I started building what you all call Cruzbikes.
I entered the HPV speed championship and crashed spectacularly after the chain managed to drop off and get under the front tire.
I did manage the road race pretty well. Glad to see that this technology has gained widespead acceptance.
Re the picture above, the designs I have seen that worked, except Fred's, have all placed the crank either before or after the steering centerline, as the changing torque of the hand crank makes steering very challenging.
Cheers,
Tom

 

[John Tolhurst]

Thanks Tom, interesting

Thanks Tom, interesting background.

 

[ak-tux]

Nice MBB with a hand crank in

Nice MBB with a hand crank in the French Recumbent Forums:

alt="FWD MBB with a Hand crank. "

More info in French here : http://velorizontal.bbfr.net/t15532p15-semaine-france-hpv-allegre-14-au-22-juillet-2012

 

[John Tolhurst]

Pretty sure its not going to

Pretty sure its not going to set any records to wit energy losses outweight energy gains.

The handlebars on your cruzbike don't seem to move, but that doesn't mean your arms are not working when your body is aimed at separating bar from pedal and disposes itself to that task as effectively as it can!

 

[ak-tux]

I agree with you John. I was

I agree with you John. I was just adding to the thread for those interested. The recumbent world is full of really strange models of bicycles. I think recumbent users tip the scales at experimentation

This hand crank idea is one good example

 

[John Tolhurst]

In Chicago, I understand,

In Chicago, I understand, there were two patent offices, one for bicycles patents and the other for patents for other things. Yes, bicycle science and design is one of the all time great challenges.