In this instructable, a wooden motorcycle ramp is created. While designing the ramp, I was primarily interested in the following criteria:
- Able to load individually (needed to be wide for feet on either side of bike)
- Light(ish) weight
- Relatively small slope
- Cheaper than ~$100 product
Let's get to it!
Step 1: Plan Out Dimensions!
I modeled a draft in SOLIDWORKS and performed a simple stress analysis (using a center load of 500 lbs) to see if the design was feasible. After a few modifications, I had a final plan.
Essentially, this plan was to make the ramp about 8 feet long and have 3.5" spacing between each of the 1" x 4"s. As seen in my fancy calculations, I accidentally thought the width of a 1" x 4" was 3.75" so my calculations were a bit off. (I will address this error later...)
To build a ramp with proper spacing, follow the dimensions below:
If everything is evenly spaced, 13 1" x 4" pieces with 12 3.5" spaces will result in an overall length of 87.5".
The width of the ramp is designed as 2 feet wide simply because of the easy division for an 8 foot piece of lumber.
Step 2: Gather Materials and Tools
The following materials and tools are required to build the ramp:
1 - Pair of Aluminium Ramp Ends ($20) -- Comes with some hardware
2 - 2" x 6" x 8' Studs ($10)
2 - 2" x 2" x 8' Studs ($4)
4 - 1" x 4" x 8' Pine ($16)
78 - 1 5/8" Deck/Wood Screws
For 2" x 2"s:
8 - 3/8" x 3.5" Hex Bolts (All hardware is just zinc-plated steel)
8 - 3/8" Hex Nuts
16 - 3/8" Fender Washers
For Ramp Ends:
4 - 5/16" x 3" Hex Bolts
4 - 5/16" Fender Washers
- Compound Miter Saw
- Handheld Power Drill
- Tape Measure
- Appropriate Drill Bits (3/8", 5/16", 1/8")
- Writing Utensil
Step 3: Start Making Cuts
The wood should be cut at 90 degrees to the following lengths:
1" x 4":
13 -- 2'
2" x 6":
2 -- 87.5"
2" x 2":
2 - 80.5"
Step 4: Predrill the Crossmembers
In order to prevent splitting the 1" x 4"s, I predrilled the screw holes. Evenly space out three holes as shown in the first image and drill small holes for the screws.
To speed things up, use the initial drilled piece as a jig to drill the other pieces.
Step 5: Create Basic Frame
Starting with the end planks, put the 4 screws closest to the corners in. (Try to be square at joint).
Once all four screws are in, use a measuring tape (as shown) to measure the two diagonals. If the diagonals differ by more than about 1/8", adjust the frame.
To adjust, simply push the two corners which had the longer diagonal closer together. Once this is done (measure after adjustment), screw in the remaining screws for these two crossmembers.
Step 6: Install Remaining Crossmembers
Now it is time to install the rest of the crossmembers. Starting at one end, use a 1" x 4" as a spacer to install the next plank (as shown in pic 1). Continue this process for the remaining crossmembers.
As mentioned previously, my initial calculations were incorrect which resulted in some complications. Essentially, I noticed that the spacing was incorrect when I had 4 remaining crossmembers to install (it's a good idea to check!).
To counteract this, I increased the spacing of these last members by 3/4", using an additional 1" x 4" for spacing.
Step 7: Reduce Deflection!
In order to increase the stiffness of the ramp, a 2" x 2" is added to the underside of both 2" x 6" members.
To do this, layout the 2" x 2"s three-and-a-half inches from either end of the planks in the center. Using a 3/8" drill bit, drill through both the 2" x 2"s and 2" x 6"s for bolts. Since these holes add stress concentrations, it is not ideal to have them near the center of the ramp.
The bolts are installed in the first and fourth gap from either end of the ramp. Don't forget to use the fender washers on both sides to prevent damage to the wood. As far as torquing goes, don't go overboard on them -- wood is pretty soft.
Step 8: Attach Ramp Ends
Since the ramp ends I purchased were designed for 2" x 8"s, the holes were too far apart. As such, I drilled new 5/16" holes about 3/4" toward the center for both sides.
Since the ramp is designed with the 1" x 4" at the mounting location, the included bolts are too short. This is the reason for some additional hardware, yet the included nuts will be used.
Using the aluminum end as a guide, drill the 5/16" holes into the wood from the underside. Once again, fender washers are used to reduce the deformation of wood. Don't torque these too tight either!
Lastly, with the ramp butted against the tailgate of your choosing, drill four holes for the pins of the ramp ends.
Step 9: Test It Out!
Before going into a pickup, I would advise testing out on a small incline just in case the ramp will fail. My bike is pretty light and with me on it is about 525lbs overall -- take caution for larger bikes (and people!).
If everything works on the test, give it a real try!
To date, I have used the ramp a few times with no problems. A paint job is likely to happen in the near future to protect it a bit from the elements.