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ST4 Fender Vent Question

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"The inner/inboard side of the fender well (any non-horizontal aspect) may have holes cut specifically for the purpose of the passage of brake ducts, external shock reservoirs, air intake hose, and brake lines/ABS wires. Plastic fender liners may be modified and/or removed. If the fender well itself is constructed of plastic, it is not considered a “liner”. The front, top, and rear aspects of the fender well may have modifications to allow vent holes for aero and/or cooling purposes (and specifically not for tire height clearance). As such, a component of the topmost aspect of the fender well must remain in the OEM location (but can be made of non-OEM material/venting). (note that ST4 has additional Aero limitations below in 6.3 and 6.4)"

"Rolled or flared fenders (includes add-on flares--only to the extent necessary to cover the tire as viewed from above—not viewed from the front or rear)"

In 6.3 and 6.4 I do not see additional limitations as applied to fender venting.  In 6.3 there is only mention of fender flares.  Is fender venting for purposes of aero allowed in ST4?


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Greg G.

From page 11 of the ST1-4 Rules--in regard to ST4 only:

"If not using the BTM Aero Modification Factor, aerodynamic parts/devices/aides shall be limited in ST4 to the following:"

Fender venting is not a listed modification, so it is not permitted in ST4.

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