Bumper Thickness

[Bpk9p4]

Is there any official rule on the thickness of the bumper. I have seen bumpers anywhere from 3.5 inches thick to 2.5. This year it would be nice to have a hard rule on it

[Hallry]

Rule R29.

[JR0405]

R29 A. "be backed by 3⁄4 in. (nominal) thick (~19mm) by 5 in. ± 1⁄2 in. (~127 mm ± 12 mm) tall plywood or solid, robust wood."

R29 C. "use a stacked pair of approximately 21⁄2 in. (nominal) round, petal, or hex “pool noodles” (solid or hollow) as the BUMPER cushion material"

[Bpk9p4]

Originally Posted by JR0405

R29 A. "be backed by 3⁄4 in. (nominal) thick (~19mm) by 5 in. ± 1⁄2 in. (~127 mm ± 12 mm) tall plywood or solid, robust wood."

R29 C. "use a stacked pair of approximately 21⁄2 in. (nominal) round, petal, or hex “pool noodles” (solid or hollow) as the BUMPER cushion material"

however it goes on to say this "Noodle compression as a result of smoothing BUMPER fabric is not
considered deformed. Any compression beyond that, e.g. for the
purposes of flattening the noodle, is deformation and a violation of R29-" so how much of that is ok?

In the past are bumpers have always been around 3 inches thick including playwood and mounting brackets. Is that ok?

[Jon Stratis]

It's really impossible to give a strict number, as pool noodle manufacture doesn't hold to very strict diameters. That said, there is a noticeable difference when holding a bumper that has been properly constructed, versus one that was constructed with the intent of flattening the pool noodles.

Go ahead an pull the fabric tight. But don't staple your fabric on while you have someone sitting on the bumper, that will flatten the pool noodles and not provide sufficient space for them to expand back out to their proper size.

[Chris is me]

I generally assume bumpers are 3.25 inches, with whatever slight compression is placed on the pool noodles offset by the thickness of the fabric. For frame perimeter calculations this year, I'm treating bumpers as 3.5 inches thick, in order to build 1/2" undersize in each dimension.

Compressing bumpers to get within the size volumes is going to be even more frowned upon / illegal than it already was.

[Jon Stratis]

Originally Posted by Chris is me

I generally assume bumpers are 3.25 inches, with whatever slight compression is placed on the pool noodles offset by the thickness of the fabric. For frame perimeter calculations this year, I'm treating bumpers as 3.5 inches thick, in order to build 1/2" undersize in each dimension.

These are good assumptions to make if you want to pass inspection!