The size range across petrol and glow aerobatic models is wide, and it’s worth understanding roughly how the classes relate to each other if you’re moving up (or down) in scale.
30-size to 50cc class covers a lot of popular sport and lighter scale aerobatic models — generally lighter, more portable, and typically the entry point for pilots moving from trainer-style models into dedicated aerobatic or 3D types. Gear, wheels, and general hardware at this end of the range are correspondingly lighter-duty, sized for the lower weights and loads involved.
80cc to 100cc class represents a genuine step up in both scale presence and structural demands — models in this range are often serious club-level or entry competition aerobatic machines, and landing gear, fasteners, and fuel system components all need to be specified accordingly rather than simply scaled up casually from smaller-class parts.
150cc and above is squarely the large-scale end, where models start to genuinely resemble their full-scale counterparts in size and presence, and where every component — gear, fuel system, ignition — needs to be selected with real margin rather than minimum-spec, given both the values involved and the consequences of a failure at this scale.
Moving up in class isn’t just “buy bigger everything.” Weight, structural loads, vibration characteristics, and fuel system demands all scale in ways that aren’t perfectly linear, which is part of why manufacturer size brackets (see Day 1) exist rather than a single universal formula — a component correctly sized for 50cc use doesn’t necessarily scale proportionally and safely to 100cc just because the numbers look related.
If you’re moving up a size class for the first time, it’s worth treating it as a genuinely new specification exercise for gear, fuel system, and hardware — rather than assuming your existing knowledge and component choices simply scale up alongside the model.
Take a look at our EXTRA 300 26cc – 35cc Carbon Fibre undercarriage for a solid example of correctly sized gear.