If you're like me, you have a friend who has a 50% deficiency in the number of hands required to ride a bicycle. Tired of watching him hunch over the handlebars to ride a bike, i resolved to create my greatest ever invention... Bicycle clampy hand!

The retail solutions to this problem cost a ton of money, require modification to the bicycle, and really arent that much better IMO. Bicycle clampy hand can be used with any bicycle without making any alterations to it. One of my design goals was that the user shouldnt have to attach anything to the bike in order to ride it.

One of my other design goals was that for safety reasons, Bicycle clampy hand should be able to be disconnected quickly and easily by the user without needing to reach over with the other hand. Whether by twisting the arm or through some other ingenious mechanism. This goal has not been met, as our test subject says it is not needed. In the case of a crash he says he can just drop the entire prosthetic arm off his nub. His primary concern was that the hand itself should never let go of the handlebar uncommanded, and that goal has been met. Your test subject may have a different take on this, and if you manage to redesign Bicycle clampy hand to add a quick release functionality i encourage you to let me know so I can link to your version and/or update mine.

As it is, the user will have to clamp the hand onto the handlebars and pull it off again using their good hand, sorry. There are some recesses in the mechanism to add springs, with the goal being that the user would at least be able to clamp onto the handlebars "single handedly" as it were, but it doesnt really work very well and I'm not sure its worth the bother. I left the recesses in though in case anyone wants to experiment with that.

We experimented with a few different configurations of the wrist joint. Ball-and-socket designs ended up being too fragile, and our test subject says that it doesnt really need that much range of motion anyway, nor did he think that it needed to be lockable. So i ended up using the "captured wart" joint from mgx's rod clasp a second time. (Mad props to mgx for that rod clasp, I use the heck out of that thing)

The wrist joint remains flopsy and loose over a restricted range of motion. The range of motion of this joint was decided on after some experimentation, but your preferences may differ. Using careful placement of additional lobes in tinkercad, you should be able to modify it to meet your needs.

Bicycle clampy hand is designed to be robust enough to take a portion of the users weight, as is normally done in bicycling. During testing Bicycle clampy hand was able to survive the user putting as much weight on it as he was able to without causing himself injury. The device was completely unfazed by this treatment, suffering no damage at all. This was done with a version that had been printed with 40% infill.

Additionally, the clamp grips the handlebar in such a way that the user can transition from sitting to standing positions and back again. However, if your handlebar grips have a significantly different diameter than ours, you may find it necessary to adjust the clampy part to suit.

You may also prefer to remove the grippy spikes i put on the inside of the clamp mechanism.

The flexi fingers do nothing and are for decorative purposes only. They were added at the request of our test subject. I attached them using some self-tapping screws, although it'd probably be better to use glue.

Bicycle clampy hand is meant to attach to an already existing prosthetic. You'll have to come up with your own "socket" for your nub.

NOTE: Bicycling is a dangerous activity. The designer of Bicycle clampy hand makes no claims about the safety of this creation and urges extreme caution in its use. I take no responsibility for your safety or the safety of anyone at any time ever, and anyone who uses Bicycle clampy hand does so at their own risk. Please be safe! Or dont. Whatever, its a free country, you do you, it's none of my business really.