[RRLedford]

The AM stealth wheels have very high coefficient of friction urethane tread and are very lightweight, so they are excellent at gripping the plastic slope of the mountain, however, like most gripping things they loose their grip once surface contact is lost when they start to elevate over the churros.

They do grip so well that even with ONLY either the front or the rear pair making good contact with he plastic, they will often still keep the bot moving forward/upward to the mid zone at least, as long as the bot stays pointed straight up slope and weight splits equally on the two down wheels. Once the bot begins to twist, then progress quickly stalls.

The big challenge is handling the effect from the axle elevation, caused by wheels contacting the churro bars with enough force/grip/torque to start elevating them off of the plastic (or not). Without some kind of wheel protrusions present and already engaging the churro(s) enough to resist slip and maintain forward climbing momentum, the slightest bit of axle rise instantly breaks most or all wheel grip on the mountain's plastic surface, and often happens before the wheel protrusions (if any) have fully engaged the churro well enough to gain and hold a sold grip onto it,

The wheels rising up on churros also tends to trigger the remaining down wheels' to lose grip as well, since even slight shocks and twists can cause them to break free of their hold on the plastic, especially when the slope gets steeper and the churro climbing wheel pairs lose good sync with their timing for their initial contact with the churros.

-Dick Ledford