First let's go over some basics.
COG: acronym for "center of gravity" and one of the most important attributes of a rock crawler.
COG refers to the center of gravity of the rock crawler, and ideally you want the weight as low as possible.
Keeping the weight low and centered will help keep all four wheels on the ground and prevent rollovers.
When looking at COG it's also important to keep your crawler balanced, try to distribute the weight evenly,
avoid having more weight on one side than the other. End to end weight balance is a little different though.
Most competitive RC rock crawlers prefer to have more weight on the front of their rig, usually positioned
on the front axle or weights on or inside the wheels, it's all a matter of preference though. A good test you can
perform to check your COG is placing your crawler on it's side, resting on the outer edges of the the wheels and
tires, your crawler should not tip over. Another test is too place your crawler against a vertical surface, like a
wall, and with your front tires on the wall see how close you can get your rear tires to the wall, the closer you
can place your rear tires to the wall without your rig flipping over backwards the better.
Belly Clearance: this typically refers to the distance from the surface (rock or ground) to the skid plate of the
chassis. More clearance will allow you to clear obstacles easier but there is a trade off with belly clearance and
COG. More belly clearance usually translates to higher COG and increased potential for rollovers. Chassis
design greatly influences belly clearance and we will cover this more, so read on.
Chassis Types:
TVP: otherwise known as Twin Vertical Plate, a good example is the stock Axial AX10 chassis. TVP Chassis's
are probably the most common type of crawler chassis and are extremely versatile. Most TVP Chassis's are
designed to have four shocks and four link suspension geometry, but there are other variations of course.
Tuber: usually refers to a custom made tube chassis, a good example is the Hustler chassis produced by RCP.
Tubers will typically resemble 1:1 custom rock crawlers somewhat, and commonly use four shocks
and a four link suspension setup similar to most TVP chassis's. For competitions a tube chassis will require
panels in accordance with USRCCA rules.
Stick: a stick chassis is normally comprised of a "backbone" and two shocks. The most common stick chassis
is sold by TCS although many people have designed and created their own versions, each one being a little
different of course. The stick chassis provides great belly clearance and well above average COG.
Torsion: refers to many different designs which exclude the use of shocks but rely on flexing of chassis
components to provide articulation. Perhaps the most well known torsion style chassis is the "Pimp Cane"
produced and sold by JP Custom RC which utilizes an aluminum "C" channel to connect the two axles and
provides articulation by twisting of the "C" channel. Torsion chassis's typically offer good COG and belly
clearance in comparison to TVP rigs.
Axles:
Shaft Driven: a.k.a. shafties or shafty's, good example being the Axial AX10 axles. Shaft driven trucks have
advantages and disadvantages similar to other designs but remain the most popular axle for mass produced
rock crawlers. Some advantages are: use of a single motor, wheel speed front and rear can be identically matched.
MOA: acronym for Motor on Axle, good example being Tamiya Clod Buster Axles and Enroute Berg Axles. MOA
axles have been the dominating axle for Super Class crawlers and are becoming more and more popular
with 2.2 Class crawlers. Some advantages of MOA axles: independent control of front and rear axles, front and rear
DIG capable, improved belly clearance due to absence of drive shafts.
COG: acronym for "center of gravity" and one of the most important attributes of a rock crawler.
COG refers to the center of gravity of the rock crawler, and ideally you want the weight as low as possible.
Keeping the weight low and centered will help keep all four wheels on the ground and prevent rollovers.
When looking at COG it's also important to keep your crawler balanced, try to distribute the weight evenly,
avoid having more weight on one side than the other. End to end weight balance is a little different though.
Most competitive RC rock crawlers prefer to have more weight on the front of their rig, usually positioned
on the front axle or weights on or inside the wheels, it's all a matter of preference though. A good test you can
perform to check your COG is placing your crawler on it's side, resting on the outer edges of the the wheels and
tires, your crawler should not tip over. Another test is too place your crawler against a vertical surface, like a
wall, and with your front tires on the wall see how close you can get your rear tires to the wall, the closer you
can place your rear tires to the wall without your rig flipping over backwards the better.
Belly Clearance: this typically refers to the distance from the surface (rock or ground) to the skid plate of the
chassis. More clearance will allow you to clear obstacles easier but there is a trade off with belly clearance and
COG. More belly clearance usually translates to higher COG and increased potential for rollovers. Chassis
design greatly influences belly clearance and we will cover this more, so read on.
Chassis Types:
TVP: otherwise known as Twin Vertical Plate, a good example is the stock Axial AX10 chassis. TVP Chassis's
are probably the most common type of crawler chassis and are extremely versatile. Most TVP Chassis's are
designed to have four shocks and four link suspension geometry, but there are other variations of course.
Tuber: usually refers to a custom made tube chassis, a good example is the Hustler chassis produced by RCP.
Tubers will typically resemble 1:1 custom rock crawlers somewhat, and commonly use four shocks
and a four link suspension setup similar to most TVP chassis's. For competitions a tube chassis will require
panels in accordance with USRCCA rules.
Stick: a stick chassis is normally comprised of a "backbone" and two shocks. The most common stick chassis
is sold by TCS although many people have designed and created their own versions, each one being a little
different of course. The stick chassis provides great belly clearance and well above average COG.
Torsion: refers to many different designs which exclude the use of shocks but rely on flexing of chassis
components to provide articulation. Perhaps the most well known torsion style chassis is the "Pimp Cane"
produced and sold by JP Custom RC which utilizes an aluminum "C" channel to connect the two axles and
provides articulation by twisting of the "C" channel. Torsion chassis's typically offer good COG and belly
clearance in comparison to TVP rigs.
Axles:
Shaft Driven: a.k.a. shafties or shafty's, good example being the Axial AX10 axles. Shaft driven trucks have
advantages and disadvantages similar to other designs but remain the most popular axle for mass produced
rock crawlers. Some advantages are: use of a single motor, wheel speed front and rear can be identically matched.
MOA: acronym for Motor on Axle, good example being Tamiya Clod Buster Axles and Enroute Berg Axles. MOA
axles have been the dominating axle for Super Class crawlers and are becoming more and more popular
with 2.2 Class crawlers. Some advantages of MOA axles: independent control of front and rear axles, front and rear
DIG capable, improved belly clearance due to absence of drive shafts.
