Question: What is the difference between landing gear made of wire vs that made of fibreglass or aluminum?

Short Answer: Wire gear is OK for just about any model particularly low wing models with short landing gear legs. When the landing gear legs are longer such as on a high wing trainer or sport tail dragger, fibreglass or aluminum is best. We are now using 7075 T6 aluminum on many models because it is as strong or stronger than fibreglass gear and much lighter.  

Better Answer: When wire gear is used it tends to bend easily if long and on an angle. This can actually be a help when training because the bending sucks up some of energy associated with a hard landing. Re-bending wire back into shape quickly becomes tedious in spite of it's low cost and energy tolerant attributes. So for example on our Discovery, Challenger and Hornet trainers where entry price is critical we use wire gear and offer stronger gear as an aftermarket upgrade. On the slightly higher priced Apache we include heavier duty gear made from either fibreglass or 7075 T6 aluminum. Both are exceptionally strong but aluminum is now favoured due to a lighter weight. Softer grade T6 or non-T6 aluminum does not stand up well in service. Beginning in the second half of 2003 we began changing most of our sport and semi-scale models that had fibreglass main gear over to 7075 T6 Aluminum. We continue to use Fibreglass when the leg length is very long such as the 120 Size Beaver.