36mm linear "Track" - Recommended for cars lowered 1/2" or more, using front springs MORE THAN 250 lb/in, or for low cars with stiff springs. Perfect for custom coil-over kits (300f/220r - 600f/375r), can be shortened further depending upon spring rate used.
36mm Front/46mm Rear "Sport" - Recommended for moderately stiff lowering springs such as Tein S-tech, Eibach, Racing Beat, H&R or Flyin Miata. Uses a combination of soft 46mm bump stops for the front and firmer 36mm bump stops for the rear to balance the car towards more oversteer, counteracting the natural tendency of the Miata to want to understeer.
46mm linear "Street" - Recommended for cars at stock ride height/stock springs or slightly lowered. A good choice for street/mild sport applications. 46mm bump stops are designed to be used for street applications and those seeking a "comfort" setup. These bump stops are used in our Street spec kits, and are designed to work best with stock springs as they are a bit longer and might not allow proper shock travel when used with lowering springs.
58mm Mixed Density - available in red, white and blue (soft, medium, and hard) densities. For 1990-2008 Miatas used for aggressive driving (on stock springs) or Stock-class autocross to stiffen effective spring rate when stock springs must be retained. Mix densitities front/rear to achieve desired handling balance (usually one step stiffer rear vs. front when using a large front bar). May also be used on Penske/Koni 28-series shocks to prevent tire/fender contact and supplement primary spring rate ala NASCAR/Indycar. Can be trimmed to make thinner to accommodate extemely lowered suspensions such as "slammed" or "stanced" street cars to gain (or limit) suspension travel, or to control ride height tire-to-fender contact on vehicles with pulled "flush" fenders.
76mm Mixed Density - available in red, white and blue (soft, medium, and hard) densities. For 2006+ Miatas, 76 red may be used as a OE replacement bump stops. For custom applications stops may be cut to varying lengths