[richar18]

Hey guys,

I am a grad student and am working on a device for motorcycle riders - it harvests energy from the rotation of your wheels to pump air into your tires, at a rate that is high enough to triple the riding time you would normally have before your tire goes flat from a puncture (while riding at about 55mph or above). The device would likely come with a warning light that you mount on your cluster, that tells you if a leak occurs, which tire it is, and if your tire pressure is below a critical point (stop riding immediately). It would also keep your tires inflated at the optimal pressure, indefinitely.

There would be two devices per bike, one for each wheel, that you would screw onto the valve stem. Each device is about the size of a 0.75" tall stack of quarters. The devices would weigh about 1.5-2 oz each, and would come with a counterbalance weight that you would put on the opposite side of the wheel to keep it balanced (or possibly an option for dyna-beads instead).

At this point, I kinda feel like I am in a vacuum using only my own knowledge of motorcycles and riding to guide my engineering process, and would like to include alot more people in my thought process. First off, would you guys be willing to take a minute to complete a quick survey (no personal info needed) and answer some questions related to this device? If so, just copy and paste the following link into your browser window:

surveymonkey.com/s.aspx?sm=wlQspx0tMCk3fG7wgd0ung_3d_3d

Second off, if you have any suggestions, concerns, or anything of the like, please post so we can get a dialogue going!

Your help and advice will be greatly appreciated!

Happy riding,

Brandon

 

[bumblebee]

I think it could be a good safety feature for leaks so you could get stopped. Wouldn't help much for a carcass failure like the dreaded "zipper" up the middle

 

[Nero Diablo]

I think it could be a good safety feature for leaks so you could get stopped. Wouldn't help much for a carcass failure like the dreaded "zipper" up the middle

How often does that happen outside a burnout or running the tyres way beyond thier wear limits.

My on concern is if it screws to the valve stem is the valve stem strong enough to support it? what about 90 degree valve stems? Are you designing this with tubes in mind or tubeless tyres? Tubeless tend to get slow leaks tubes go down fairly rapidly.

 

[benroe]

90 degree valve stems are the future. So design them with this in mind. Also will it have a pressure regulator, say to keep it at 32-36 psi?

 

[richar18]

Hey guys, thanks for the responses and survey hits!

To answer your questions:

The initial release will be for straight valve stems only, as the configuration must change drastically to work with 90 stems. There will be a significant amount of pent-up demand for straight stem compatible devices for some time, and that will be the first niche. 90 deg compatibility will be next though.

Regarding valve stem strength, the device will be connected to a "spacer" that surrounds the valve stem, and touches off on the rim surface. This will be loaded in compression by centripetal forces, and will support all of the load. It will also absorb any bending moment caused by hitting a bump, especially at speeds above 25mph.

Tube or tubeless - the device will be targeted to the tubeless market, which makes up the majority of tire configurations. It will likely be of much less benefit to tubeless folks, however a much cheaper version (~$35, no pressure monitor) may be sold that does only the job of keep tires at optimal pressure.

The device will have an adjustable pressure regulator, that allows the user to specify the pressure.