RC Car Tire solution (For Known or Ksoth)

If you remember my previous thread- electric help, I've been thinking more and more about the tires and after actually tinkering with some models of the tire, decided that I'd make it similar to how a lock works where there are raised points and not raised. The mechanism moves in and out, in the spikes r out since their bottoms r against the raised portion, out the spikes r in. Here are a few pics:
<A HREF="http://www.imagestation.com/picture/sraid66/pa2ef5f321898ed32d0e7009cf7586a58/fbdeb06b.jpg" target="_new">Pic 1</A>
<A HREF="http://www.imagestation.com/picture/sraid66/pc354b400d67f2e2572b6270ecca782a6/fbdeb066.jpg" target="_new">Pic 2</A>
<A HREF="http://www.imagestation.com/mypictures/inbox/view.html?id=4225675365&url=http://www.imagestation.com/picture/sraid66/p1ff0f8d699468be8669271bec0003cdd/fbdeb065.jpg&caption=tire3" target="_new">Pic 3</A>
For keeping the spikes in I'm debating whether to have a slightly broader end and then there's a spring which pushes spike in or having it go on "rails" on the "key" that keep it in.
Also, w/ a 4:1 gear ratio, 1.98amp motor spinning at 18,000 rpm and eating 18V, 350g-cm torque, and 4 of such motors, how much weight can this car bear and still keep that up? It may have to go to 15-17lbs. because of the batteries...Would that work?

All the things I really like to do are either illegal, immoral, or fattening.<P ID="edit"><FONT SIZE=-1><EM>Edited by flamethrower205 on 06/22/03 03:27 PM.</EM></FONT></P>

I think you're looking into a world of frustration going the retractable spike wheeled route. I'm not sure what you mean with your description, and how you expect to pull it off.

I don't know exactly how much weight your car could be with 4 of those motors, but 15-17 pounds is pretty heavy and may be too much. What you'll need to do is just keep adjusting the gear ratio after you get the car build to see what allows it to work. The wider the gear ratio, the greater the torque, so the less chance of stalling out the motors. But, doing this will reduce top speed for you as well.

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<font color=blue> "Trying is the first step towards failure." </font color=blue>

What R/C are you running? On some racetracks, they spray sprite or coke on the track so that the tire grips better. IF you use spikes, there is less of an area for the tires to grip the surface, most likely making it loose traction. www.geocities.com/ihaterc are my R/C cars