Autism, Third Wheels, and a Hammerhead Tadpole Trike

Our son, Scott, has been struggling to ride a bicycle for the last four years. Even at age eleven, he has training wheels. There’s still a wobble with training wheels and no real sense of security. If I tried walking alongside him and holding onto his bike to keep it steady, he would quickly let go of the handlebars and cling to me as if his life depended on it. With each wobble, absolute panic would generate terror that would freeze him from all movement. For four years, he was incapable of riding his bicycle.

We didn’t really know why.

Scott has a desire to be like other kids. He had a strong desire to ride a bike. His little brother has been pedaling without training wheels since about age seven. His friends in the neighborhood ride bikes all over. The best Scott could do was lie down on a skateboard and wheel himself along with his friends. Of course, this made him a bit of a third wheel.

We thought he might “grow out of it,” or that maybe just a bit more practice and exposure to the bike would lend him more confidence. For a long time, we thought it was weak muscles. If he only worked on his core, he’d have the strength to master the bicycle. Over and over again, every spring and summer, we kept trying to encourage him as he faced his fears and attempted to ride this bike.

It finally occurred to us that this was more autism related than a lack of strength or skill.

One of the senses that affects kids with autism is the vestibular sense. Our vestibular sensory system helps our bodies maintain balance and an understanding of spacial orientation in the world. Your vestibular sense keeps you upright, allows you to bounce and catch a ball, and helps you balance while you ride a two-wheel bike.

As we researched autism and all of the senses the condition affects, we discovered that to Scott — to his brain’s situational awareness in the world where all of his senses come in unfiltered and out of sync — his perception is that his life did depend on him clinging to me. Much like vertigo can attack someone with a fear of heights, as soon as those wheels wobbled even fractionally on his bike, his brain immediately told him that his life was in peril. No amount of encouragement could redirect him long enough to focus on his other senses and control the bike.

To our little third wheel, he felt like he was drowning while fleeing from a shark.

Hammerhead Shark

Hammerhead Shark

We struggled with what to do. Continue to encourage the bike? Insist that he keep trying? We found ourselves kind of on the fence about the best way to go forward. Next summer, he’ll turn 12 and will be experiencing that somewhat halcyon time between elementary school and middle school — yet he still couldn’t ride on bikes with his brother and his friends up to the local library or corner convenience store.

Recently, a friend hosted a lunch that allowed a couple of us with kids to get together and give the kids a play date while we moms enjoyed a beautiful afternoon of fellowship. This friend had an adult-sized “delta” trike – that is, with two wheels in the back. Scott got on that thing without hesitation and rode it like a pro – flying down the road as fast as he could pedal. Fearlessly. FAST and with a lot of strength. For the first time in his life, he rode.

Scott Rides a Delta Trike

Scott Rides a Delta Trike

Seeing him do this taught us that he isn’t afraid of riding – or even riding at high speeds. He isn’t weak. As soon as the large, wide, stable wheels of the trike supported him, he was completely fine.

Our third wheel son needed a three wheeled conveyance.

Gregg started researching trikes and autism and specifically the vestibular sense. He learned that the trikes with the wheels in the back, the delta trikes, while generally very stable riding in a straight line, can very easily tip over if the rider brakes and turns at the same time. The problem is that the front wheel is at an angle to the direction of travel and when the rider brakes, all of the body weight and centripetal force and kinetic energy of the rest of the entire trike transfers onto that lone front wheel which is already experiencing angular momentum. Flip!

In his research, Gregg found and purchased a set of plans from Atomic Zombie for a “Hammerhead Tadpole Trike”. A tadpole trike has two wheels in the front and the rear wheel is the braking wheel. This puts two wheels at a proper configuration to the circumference of the turn while the braking drag is all in the rear most part of the trike. This is called a “hammerhead” tadpole because the configuration of the steering linkage and the front wheel braces resembles a hammerhead.

hammerhead design

hammerhead design

The design has a complex Ackerman steering system that involves a principle which allows the innermost wheel to turn more sharply than the outermost wheel in a turn. That helps the trike remain upright and stable during a turn, even a fast braking turn. It is designed to accommodate riding through snow and ice, so Gregg knew that a similar design would work for Scott on grass, gravel, sand, or roads and sidewalks.

We just needed a couple of “donor” bikes and a good bike frame to build it. We live on Fort Knox, Kentucky, so he took the plans he’d bought to our neighboring town of Radcliff to Outdoor Ventures, a bike shop just a few miles up the road from us. They were very interested in the project and wanted to do what they could to help us get our young son onto his own trike. After talking with Gregg and meeting with Scott, the owner basically donated some bikes and bike parts to the project.

A coworker who Gregg has known since Afghanistan connected him with a friend, Al, who had the welding tools and skill needed to weld all the elements of the trike frame together. He obtained some steel and riding lawnmower steering bearings from the local Rural King and ordered a few spherical bearings just in case. After ordering various pieces and parts, collecting different bikes and bike parts, Gregg prepped what pieces needed to be cut or ground down and sanded, inventoried all of the pieces and parts, and delivered them to the welder, Al.

Gregg cuts apart some donor bikes

Gregg cuts apart some donor bikes

Donor bikes and bike parts

Donor bikes and bike parts

Donating all of his time and talents, Al welded the parts Gregg brought him and built the frame of the bike.

The "hammerhead" frame mocked up with tack welds and clamps prior to final welding

The “hammerhead” frame mocked up with tack welds and clamps prior to final welding

Being a true pro, Al gave the hammerhead an even wider stance for greater stability and strength.

the complex steering

Gregg purchased racing forks and mag-wheels from Outdoor Ventures, put a comfortable wide seat on it, tightened the brakes to hair-trigger responsiveness, and let Scott give it a go.

Scott loved it so much that he insisted he didn’t even need it painted. Despite that, Gregg took it all apart again, sanded down and smoothed out the areas where it was welded, teflon taped all the threads, and puttied all the spaces with JB Weld. Then he primed it and gave it a bright neon green top coat — Scott’s favorite color.

This past Sunday, our family rode our bikes/trikes to church together for the very first time.

We’re having to battle the words that other children say when they see the hammerhead for the first time. “That looks weird!” “What is that?” At first, these comments made Scott come home and not want to ride again. He thought the kids were mocking him, but we also heard them say, “I want a 3-wheeled bike, too!” “Can I ride it?”

Despite that, when he gets on the seat and starts pedaling and re-introduces himself to the freedom of wheels and the feel of the wind against his face, he realizes it’s okay if kids stare and ask him questions about it. Because he’s free. He’s having a real adventure, and little boys need adventure so they can grow into confident men. And he is able to join his brother and his friends as they storm the neighborhood on their bikes.

Gregg took them out in the neighborhood every night this week, chasing the sun, and watching him bike up hills, across grassy fields, and down the road without even slowing down, never afraid, ready to keep going forward. Last night, as they were putting the bikes away, Scott said, “Thanks for building this for me, dad. I love it.”


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    • Sherri G on August 18, 2017 at 08:21
    • Reply

    This is so awesome! I can relate a little to Scott and learning to ride a bike. I had 3 older siblings who all rode bikes, of course. But I couldn’t seem to learn. Something about not having my balance threw me off every time. Finally in the 4th grade, I was determined to learn. I got at the top of a small hill and rode to the barn at the bottom. I completely forgot about braking and had a painful surprise when I hit the barn. But I managed to get the hang of it after that. I’m glad for Scott that he can join in on the fun now.

    1. There’s a trainer bike that is low to the ground and has no pedals. You’re supposed to just let the kid drift down small hills and driveways and learn to balance. Our neighbor loaned us one but he couldn’t do that one, either. Sounds like you did that same thing yourself!

  1. My heart grew larger reading this ~ with much wonder, thankfulness and respect for:
    • the way God providentially placed the 3-wheel bike at that play date
    • Atomic Energy
    • Outdoor Ventures
    • Al the welder
    • Gregg’s loving, overwhelming commitment to his children
    and most of all –
    • For Scott’s fearless, joyful mastery of the “hammerhead” bike

    Father in Heaven, I thank you and praise your name for moving everything in place for a young boy whose simple wish was to fly through the streets and feel your wind in his hair.

    1. This made me tear up. Thank you.

    • Bonnie Roof on August 18, 2017 at 12:00
    • Reply

    Such a beautiful, touching story – so glad Scott can ride a bike now too!! Thank you for sharing!!

    1. Thank you, Bonnie!

  2. What a great story! Our son has autism and is 11. We just bought him a new bike and even with training wheels, he hates to ride. We may have to look at one with three wheels like the first picture you showed. He might like that a lot better. Thanks so much for sharing!

    1. I would recommend the one with the two wheels up front — simply because the “delta trike” is such a tip-over risk.

    • Charles McFeron on August 18, 2017 at 23:09
    • Reply

    I would suggest going to one of the low slung recumbents,I ride a tadpole style trike and and atomic zombies marauder,, the trike is very low reducing tip over risk,, and feels amazingly fast

  3. That is so incredibly cool!

  4. Prayers for Scott. Thanks for sharing..

  5. I would recommend going to one of the low threw recumbents, I ride a tadpole style trike and nuclear zombies pirate, the trike is low decreasing tip-over hazard and feels incredibly quick

  6. Thanks for sharing so much interesting work. God Bless you. I love skateboarding in my free time.

  7. Amazing story. Thank you for sharing your story. Inspiring. You are a blessing for your child. God Bless You!

    • Deanna Jennings on September 19, 2019 at 22:31
    • Reply

    How wonderful to see him succeed after trying for so long!

  8. Hey Hallee,

    Thanks for sharing lot of information for wheels. That’s great!

    Nurnabi recently posted…Punisher Skateboard Review in Current MarketMy Profile

  9. I read your article and love this well-researched content. Your content is information-rich. I want to ride a trike but don’t know about its facts. After reading this I learned a lot.
    Franciso Cole recently posted…10 Best Pedals for Gravel Bikes -[Flat and Clipless Both]My Profile

  10. What a great story! Thank you for sharing your story.

  11. I learned a lot today about trikes. Thanks for sharing the detailed article.

  12. Really nice post. Thanks for sharing this information.

  13. Hi
    Such a Nice post and a great story i love to read it again and again

    1. Thank you, James.

  14. thanks, amazing post really inspiring

  15. this is one lovely story.

  16. You’ve done a very good job.
    Thank you for sharing this story with us. This is really worth sharing.
    Michael Burnley recently posted…Is Skateboarding Bad for Your Knees? (Right Ans)My Profile

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