Which rubber thickness should I choose, 1/4" or 3/8"?

The rubber paddles used in our Snow Blower Impeller Kits ™ are Styrene Butadiene Skirtboard (SBR) rubber with minimum tensile strength of 725 PSI (5 MPA), a Temp Range: -20 F to +170 F, a durometer of 65 ± 5 (durometer is a measure of durability). For comparison, a car tire tread has a durometer ranging (depending on the make/type of tire) between 50 - 70, and shoe heel rubber a durometer ranging from 65-80. As such, this rubber used is quite durable over a wide range of weather conditions and has a high tensile strength rating meaning it doesn't break easily.

Styrene Butadiene Skirtboard (SBR) rubber, in 3/4" - 1" thickness, is also a material of choice for use in snow plow rubber applications. It is notable to remember that any substance impacting a harder substance (such as a stone or chunk of ice) will always lose out to the harder substance, so even though this rubber is tough, it will be damaged when impacting a harder substance and so it might be a good idea to keep spare rubber paddles on hand.

As for the two different sizes of kit available, the 1/4" & 3/8" kits refer to the thickness of the 2"W x 5"L SBR rubber paddles. Basically, the 3/8" thick paddles are 50% thicker and so are considered to be "heavy duty". While both the 1/4" and 3/8” rubber paddles move all types of snow effectively, the 3/8" inch thick rubber paddles will last longer and handle a heavier/wetter load of snow for a longer period of time than the 1/4" thick paddles. As such, you should consider what your needs are in regards to the amount and consistency of snow you normally receive and order appropriately.

Generally, the heavier, wetter and deeper the snow, the thicker the rubber paddle for greater performance and longevity. As long as a kit is installed on each impeller blade to ensure uniform harmonic balance, the difference in rubber thickness should have no effect on the impeller shaft bearing.