Specifically for the QRF400, the 4 Spring set includes various rates of travel and hardness. Great for loose dirt, grass, concrete, jumps or rocky surfaces. (Compatible With ARX-540)
Length: 37mm(Short), 42mm(Long)
Inside Diameter: 17mm
1 x Short Red (Hard) (Great for wheelies, and concrete surfaces)
1 x Short Yellow (Soft) (Grass or loose dirt, larger turning circle)
1 x Long Red (Hard) (Big jumps, rough ground)
1 x Long Yellow (Soft) (Sharp steering, soft dirt, sand)
Very cheap springs!
Used the longest red one in my E-Revo 1/10 it's the same size. Stiffer than the oem gold ones.Bought it more for color variation on the bike. Overall good quality spring set. For info the stock black spring that comes with the bike is the hardest.Good shock set. Tried different shocks with different oil till the bike drove well.