Audible Speedometer

[Leisesturm]

My stoker (blind) and I took our first ride of our second season as a team. I was doing a little experiment in determining how well she could estimate how fast we were traveling at various points on the trip. As I suspected she was primarily using the force of the wind in her face to judge our speed. A stiff headwind throws her estimates way off as do tailwinds. Of course pedal cadence factors in her assessment too but of course this is just as subject to error as I am a spinner and so by default is she. Our high cadence leads to inflated estimates of speed. I started brainstorming on a device that would audibly call out speed like the audible tire pressure gauges. She said she would like something that used a rising pitch as speed increased. Seems like either would be doable for someone with the right skill set. Has anyone ever come across anything like this? Does anyone think they could make such a thing from commercially available parts (Radio Shack?). TIA.

H

[djembob02]

What you propose would make sense.

I'm thinking that another way to do it would be to have the computer give an audible sound such as a tic or pulse each time the wheel goes around. As an expirement you could try putting a piece of tape or a cable tie on one of your spokes that sticks out like a flag enough that it would hit the seat stay. If this works I think you could somehow convert your current speedometer's electric pulses (measured by the magnets meeting).

I'm still thinking about how this conversion could be done...

[zonatandem]

There are enough non-sighted stokers out there, that there could be niche market for such a system.

[djembob02]

I've had some more thoughts on this, though I haven't had any time to put my theory into practice. Unfortunatly I don't know exactly how the cyclocomputer works. I have spare computer and I will try to figure some things out.

Here's my theory, have some kind of sound making device. The first thing that comes to mind would be a cheap mp3 player. The "song" that it would play would be a constant tone.

Then a headphone (probably only one ear) would be plugged into the mp3 players.

Cut the headphone wire, cut the cyclocomputer wire. Solder the wire together in an appropriate way so that the circuit is broken when the magnet is not in contact. When the magnets meet, the circuit would be complete.

Again, this is all in theory. I honestly do not know if this is how cyclocomputers work. I will try to find out. If interested in this type of set-up, let me know and I will try to make it. I have no idea how to program something to turn it into different tones.

Having said this, maybe there is somebody out there who would know how to manufacture something that could actually convert whatever signal a cyclocomputer gives into sound instead of visual.

[Jinker]

All I keep thinking when reading this is a hockey card clothespinned to the frame.

Tickatickatickaticka...

Going with that idea though, something which emits a gentle ticking once per revolution might not be such a horrible idea. Certainly not as involved as hooking up an electronic device which will accomplish basically the same thing.

Put something light on a spoke, and set it up to strike a piece of plastic. Something durable/resilient like a section of margarine container?

You could get really fancy and put the output from a cyclometer sensor through a tiny amplifier (would just be a clicking noise) and put that to a speaker or headphone, but that seems needlessly complex.

[cfblue]

SOME of the fancier GPS units have talking route instructions, "left turn in 1/4 mile" sort of thing. I wonder if any small enough to fit on the bike could be programmed to tell you the speed, every so often, or eevn moe info like distance/speed/average?

However, I love the silence out in the country and any such noisemaker would drive me crazy, so the privacy of the ear piece for the stoker would be needed

[Fenlason]

How about using a generator, and hooking the wires up to the capt. seat. One could tell the speed by the volume. or pitch of the capt. screams :eek: :rolleyes:

glenn

[TandemGeek]

Similar idea: http://www.ski.org/Rehab/sktf/vol05no1Winter1984.html#audible

[la2sei]

Motionlingo produces a GPS unit that has an audio output giving reports of your distance, speed pace etc. you could hook it up to a small set of speakers, or into a tandem talk unit.
http://www.motionlingo.com/

[IanJ]

A cyclocomputer uses a magnetic switch, usually a reed switch, to time the speed of one tire revolution. You could use that switch to switch a tone generator, rather than providing a pulse for a cycle computer. Making a tone generator out of an RC circuit or a 555 timer is a simple thing, and can be built with minimal electronic skill. Google around for "oscillator circuit" and you'll find the thing you need.

The other, lighter/cheaper (in terms of batteries, anyway) way to do it would be to make the same circuit, but use a magnet and pickup coil to generate a pulse of power. That power goes to the osc circuit and makes a tone, but only as often as the magnet passes the coil. No batteries needed, it just uses a little bit of your forward energy to make the tone.

For what it's worth, I bet Radio Shack carries oscillator kits, so you wouldn't even have to find any materials.

[edit] For instance, this kit here: Rainbow Morse Code Oscillator (http://www.mtechnologies.com/rainbow/#osc). Build that and hook a 9V battery to it, and a cycle computer's mag switch to the "morse code key" terminals, and you'd have a quick and very cheap audible speedometer.

[Leisesturm]

Thanks all. That Adeo GPS is a nice little unit. I paid 3X the asking price for my Garmin Quest. Of course the Quest is a fully functional GPS with navigation capabilities. Its only flaw is it does not provide audio unless powered with 12V. The other ideas including the very low tech 'striker' idea all have merit. We've been too busy riding to get to any of them. Last season I found it a bit burdensome to always be having to inform my stoker of incidental minutiae. Things that captains with sighted stokers take for granted i.e. that a parked car has suddenly lunged out into the road necessitating a quick stop jar my stoker and require several seconds of explantation afterward. I am gradually learning to stop wondering why she can't simply accept that I am doing what has to be done to insure both of ours safety without comment and trying to 'enjoy' keeping up a play by play. OTOH she doesn't at all balk at 40mph descents! Seems a fair trade...

H

[regomatic]

I don't know about the audible speedometer, but we do have an audible governor on board. She's fine with anything up to 40. Over 40, if I try to push it, I get an audible message loud and clear.

[King of Kadence]

I recently bought a Schwinn Twinn that came with an old fashioned odometer mounted near the front axle, that's actuated by a tab on one spoke. It made an awful tapping sound every revolution of the wheel. I took it off because of the noise. That might be a good low budget solution for your audible speedo.