Heavy Duty Bicycle Training Wheels

by zeraus in Outside > Bikes

2532 Views, 5 Favorites, 0 Comments

Heavy Duty Bicycle Training Wheels

IMG_20201028_072219.jpg
IMG_20201012_183113.jpg

This summer we got a new bike for my son, it was the first time he was trying to ride one and he was hesitant and a little afraid to fall. I decided to install training wheels, the classic ones, but, they broke just after 2 minutes.

I was interested to build ones a little more robust. I started looking and I found urbanmx instructable https://www.instructables.com/Quiet-training-wheel... I liked the robust and silent wheels but I decided to use even bigger ones.

The final outcome was very good, even a full size adult can use them without a problem and the design concept can be used on full size bicycles.

Supplies

Material.

- Two 8” x 8” 3/32” thickness sheet metal plates

- Two cart 10" wheels: https://www.amazon.com/NK-Rubber-Tubeless-Utility...

- Two 3/4” diameter Steel rod, length: 500mm (20”)

- 6x U-Bolts with plates and nuts

- 4x 3/8" x 1 1/2" long hex bolts with washers

- 4x 5/8" hex nuts

- 12x 1/4" dome nuts (optional)

- Black paint

Tools:

- Metal lathe

- Bench vise

- Hand grinder

- Bench Drill and/or Hand Drill

- Metal saw

- Drill bits: 3/8, 5/16, 1/4

- Wrenches

Modify the Steel Rod

IMG_20201012_183731 - Copy.jpg
IMG_20201012_184316.jpg
IMG_20201012_183939 - Copy.jpg

The steel rod had to be machined to include some of features.

- 5/8 diameter, this feature will receive the wheel

- 5/8 thread

- Add a couple of flat sections, ** this step is optional

- Include a 3/8" x 1 1/2" slot ** This step is optional, a single 3/8" hole is also ok

- One 3/8" hole (do this later after you are sure there are no conflicts with the bicycle frame)

Bend the Steel Rod

IMG_20201012_183710.jpg
IMG_20201012_183939 - Copy - Copy.jpg

Use a heavy duty bench vise to bend each rod twice using a 1" diameter pipe.

Before bending add a couple of notches with a hand grinder to guide the bend at the desired spots.

The final angle is 90° between the horizontal and vertical sections.

Map the Bicycle Frame

IMG_20201012_184819.jpg
IMG_20201012_184956.jpg

Use a 8"x8" rigid foam and hand drill a 3/8 diameter hole. Use this feature to install the rigid foam to the rear wheel shaft.

Next, use a pen and start mapping the bicycles frame.

Map the Frame, Part 2

IMG_20201012_185737.jpg
IMG_20201012_185805.jpg

Include the individual frame segments and specific features

Add the Fixing Hole Locations

IMG_20201012_190633.jpg

Find the locations to install the U-Bolts and present the bended rod to find a good location

Transfer the Design to the Steel Plates

IMG_20201018_195441.jpg

Hand drill the rigid foam.

Locate the foam on top of one steel frame, align the bottom and left edges, then, transfer the holes locations

After hand drilling the holes please take the rigid foam and try to install it on the bicycle, use all the u-Bolts and bolts, this could eliminate a future headache if there are holes out of position.

Drill the Holes on Both Steel Plates

IMG_20201018_200340.jpg
IMG_20201018_204132.jpg

Align and drill both steel plates at the same time.

Each u-bolt will have 2 holes. On the steel plate, the bottom one must have the u-Bolt diameter, but, the other one could be a little bit bigger to absorb any assembly tolerances.

Cut the Steel Plates

IMG_20201020_110247.jpg
IMG_20201020_111821.jpg

I used a regular metal saw to slowly cut the steel plates to its final size and to add a big chamfer as that part is not necessary.

File the Parts

IMG_20201020_113443.jpg
IMG_20201020_113547.jpg

With a regular file I removed all the sharp edges

Paint the Steel Plates

IMG_20201021_220343.jpg

Just clean the surface and paint with an acceptable color depending on the original bicycle color.

Assemble the Components

IMG_20201027_203729.jpg
IMG_20201027_203938.jpg

Now I started the assembly.

And, there was a pending hole on the plates, the upper hole for the round rod. I decided to do it last to make sure everything was located and aligned fine at the end, with this single hole I blocked any possible slip between the rod and the steel plate after repeated bicycle rides.

Tightening Everything

IMG_20201027_203737.jpg
IMG_20201027_204207.jpg

The u-bolts I got were larger to ease the assembly, and at the end I just cutted the extra length, leaving just enough space to later install dome cap nuts.

Testing

IMG_20201028_072306.jpg

Testing was very good, I just added a second 5/8" nut for each wheel to block any nut movement.

One Happy Kid

IMG-20201029-WA0000.jpg

And now lets keep riding with confidence. The final user approved the result with constant rides in the park.