What is that weird thing?

September 29, 2005 2:56 PM

WhatIsThatWeirdThingFilter: every now and then I spot a car or pickup with this weird attachment to the rear wheel on the driver side.

It's like a spindle attached to the center of the wheel and, fixed to the end of the spindle (which sticks about 6 inches out from the wheel), is an attachment from which a 1/4 inch diameter cable runs. Oftentimes also attached to the spindle is something which looks a bicycle disc brake.

I've mostly seen them on large pickups, but I saw one recently on a car, and the cable went into the rear passenger area - weird!

So: what is that weird thing, and what's it for?

(If my description's rubbish, press feel free to fire questions at me.)

posted by russmail to travel & transportation (17 answers total)

Is it a sensor pack for road-testing of wheel designs?
posted by mbrubeck at 2:59 PM on September 29, 2005

Could be something similar - what I've seen doesn't look like the device in the picture, but there again, maybe that's particular to a big rig.

It does seem a bit odd though that you see people with them randomly around LA - today it was one of those huge pickups with 4 rear wheels, the time before, a beat up Honda Accord.

Come on - I can't be the *only* one that's ever seen such a thing....
posted by russmail at 3:25 PM on September 29, 2005

You aren't, but the rest have already been picked up by the alien overlords. You're the only one left who can warn mankind.

That and I have no clue, myself.
posted by Atreides at 3:44 PM on September 29, 2005

It could be the mounting spindle for a particular brand of snow chains. Spider spikes?
posted by pgoes at 3:53 PM on September 29, 2005

A tire-pressure adjusting system? In the Hummer they call it CTIS, see a photo here.

Here is an image of a similar but less sophisticated system (original link here)


I think these are standard equipment on Hummers, but I can't imagine why anyone would have one on an Accord.
posted by Brian James at 4:15 PM on September 29, 2005

Sounds like a curb-finder. Looking for a picture right now.
posted by peep at 4:25 PM on September 29, 2005

Ooh - it looks like the thing attached to this Porsche wheel, but without all the mechanics attached to the chassis.
posted by russmail at 4:38 PM on September 29, 2005

It sounds like some kind of winch, like this?
posted by fleacircus at 4:48 PM on September 29, 2005

OK - now that I've been able to find an image remotely related to what I'm on about (above), even if you don't know what it is, has anyone else ever at least seen one?

I'm starting to think I'm going a wee bit mad....
posted by russmail at 5:16 PM on September 29, 2005

It may be a testing sensor in auto industry.
I have very close friend who works in one of big 3 company as an engineer.

According to him,...

Texas is world's largest market for pickup trucks and auto companies often test their vehicles in the state. They usually test vehicles in Arizona and New Mexico... but Texas is good real world testing place... You see them everywhere in Detroit areas too...

Many times they are mounted on disguised vehicle or even older vehicles to test out new or modifed parts.
Even if the car looks like anyother cars, they are just a disguises... You be surprised what some new car chassis and suspensions were mounted to what bodies...

It may measure exact rotations, efficiency, etc.. etc...
They can not just use dash gadges..(not accurate enough)
posted by curiousleo at 5:35 PM on September 29, 2005

Have you got a rally hot spot around you? Most rally cars use induction pickups or tie into the factory speedometer but there are still some old school types or those rallying rentals that use a mechanical pickup mounted on hub caps that goes to a computer inside the car. They look just like your picture except just a cable goes into the car.
posted by Mitheral at 6:35 PM on September 29, 2005

I think these are standard equipment on Hummers, but I can't imagine why anyone would have one on an Accord.
I can't think why anyone would want one on a Hummer. In fact, I can't think of why anyone would want a Hummer.
posted by Neiltupper at 6:52 PM on September 29, 2005

In fact, I can't think of why anyone would want a Hummer.

Obviously you've never met Eccentrica Gallumbits.
posted by ROU_Xenophobe at 7:12 PM on September 29, 2005

Yes! - I did see one once on a pickup that had a black fabric cover - it was kind of an all over Bra.

Also, I live in Hollywood so I don't think there's a rally hot spot nearby, but the thing from the picture with a cable going into the car is pretty spot on in terms of what I've seen.

(oh and please don't tell me no-one's ever seen a car or pickup completely covered in an all over Bra...).
posted by russmail at 7:21 PM on September 29, 2005

It could be a wheel torque sensor.
posted by rfs at 7:27 PM on September 29, 2005

Russmail, when a car company is doing tests of a new vehicle, they often obscure it with cloth covers like you're talking about. It hides the body stying from the car paparazzi. See Car and Driver's "Spy photos"....
posted by cosmicbandito at 8:13 PM on September 29, 2005

Yes, cosmicbandito - that's exactly what I mean. So I guess seeing some sort of data capturing device on a prototype makes sense.
posted by russmail at 10:26 PM on September 29, 2005