Bike bump bend plywood

[juanxxx]

Hello,
I am planning to build speed bumps according to the attached drawing and image.

The only thing I'm unsure about is what type of board material I should choose (type and thickness) to be able to bend the board as the bump is supposed to be.

My initial thought is to use 12 or 15 mm construction plywood.

What type of board should I choose? Is it easy to achieve the bend? I will be screwing in beams that are quite close together.

 

[Ingenjör Jesper]

The instruction stating 1/2 inch to the sides and 1/4 inch to the surface is a good suggestion, isn't it? Even though I think 6 mm sounds weak...

 

[Thomas_Blekinge]

It's stated in the text. 1/4" plywood. That's about 6.5 mm.

 

[Picea]

In the youth years, the 90s, we built a lot of ramps in various sizes. Rode BMX and skate, kick scooters didn't exist. We learned an incredible amount about technology and construction by trying and rethinking our ideas. We scoured containers and loading docks for materials that we used for building, we used everything from pallets to old bed frames. The concept of "recycling" didn’t exist either… We ordered designs from the USA, which arrived in the mail just in time for the end of summer break What times!
You shouldn't use 12 and 15 mm, as already mentioned. They will be annoyingly stiff. Closer joists or double 6.5 plywood will do the trick.

 

[juanxxx]

The instruction that says 1/2 inch to the sides and 1/4 inch to the surface is a good suggestion, right? Even though I think 6 mm sounds weak...

Thanks! I read 1/2 inch for everything. Thought it sounded thick. But now I know

 

[juanxxx]

In the youthful years, the 90s, we built tons of ramps in various sizes. Rode BMX and skated, kickbikes didn't exist. We learned an incredible amount about technique and construction by testing and re-evaluating our ideas. We scavenged containers and loading docks for materials we used to build, using everything from pallets to old bed frames. The concept of "Repurposing" didn't exist either... We ordered drawings from the USA, which arrived in the mailbox just in time for the end of summer vacation What times!
You shouldn't use 12 and 15 mm, as already mentioned. They will be awkwardly stiff. Denser framing or double 6.5 plywood works wonders.

Do you think 6 mm plywood will be too weak? Should I go for double layers?

Is it worth treating this type of bump with something (like paint) for increased durability?

 

[useless]

Thicker than 6 mm will be difficult to bend like that. To increase the strength, you glue on another layer.

 

[Ingenjör Jesper]

If the studs are 45 mm and spaced at 150 mm centers, I find it hard to see how 6 mm wouldn't be sufficient... It seems more like the studs bear all the weight, and the board is there to make it smooth...

 

[Troberg]

If the studs are 45 mm and spaced at 150 mm center-to-center, I find it hard to see how 6 mm wouldn't be enough... It’s more like the studs are carrying everything and the board is just there to make it smooth..

With 150 mm center-to-center and a 45-stud, do you even need plywood? Isn't it better to just reduce to CC45? Sure, it uses a bit more stud, but it's probably cheaper than plywood...

 

[MrJay]

15mm Plywood.

 

[Picea]

[media]
15mm Plywood.

However "-Seven mil ply..." "Double up..." for the topsides

 

[MrJay]

However "-Seven mil ply..." "Double up...." for the uppers

Fully possible, I only saw the beginning where he says 15 mil. I think if you're interested, you'll watch the whole clip

 

[juanxxx]

With CC 150 and the 45-rule, do you even need plywood? Can't you just reduce to CC45? Sure, it requires a bit more framework, but it's probably cheaper than plywood...

Small children will bike on them (and myself, of course). Then it's nice with a bit of comfort