Rear Seat needed for 5-year old 50-pound very hyper child
 

My son has been riding with me since he was a year old. First using the green seats that attach to the handlebar, then using the Topeak seats. I just bought an Xtracycle with the hooptie bars (handrails) and the U-tubes (foot rests). My child won't stay quiet and swings from side to side or front to back. The Topeak seat had a 3-point harness that prevented this.

Before I do a frankenstein on that Topeak seat and cut it up to fit it into the Xtracycle, can someone please recommend a larger seat that can accommodate kids 50 pounds and bigger? I'm thinking of cutting off the foot rests on the Topeak and saw off the sides so that he fits. But before I do that, what have others done in a similar situation?

The only seats I have seen for larger kids such as the Yepp Junior and similar, all use a single waist strap. I don't think a three point would be easy to execute on them either. Best best might be to do what you're thinking and chop off the foot bits on a "normal" kids seat and just make it work.

you might consider moving to trailer at this point. 50lbs is getting "outside the design spec," don't ya think?

Resolution
 

I ended up buying a cargo bike, a Yuba Boda Boda actually. Not only did I need to support the weight but also have a way to keep him grounded and protected from falling.

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At that age and weight the child should be pedalling themselves on a tag-along.

I have a wee-ride tag along bike for my 5 year old. I am aslo looking for a tandem that I could put an set of raised peddles for him. He is going to get heavy in a trailer fast!

I was going to suggest a front-loading cargo bike. I love my Douze. I can't see your pictures, but wouldn't the Boda Boda be pretty much the same as an Xtracycle, from a keeping-kids-strapped-in perspective?

The Yuba Boda Boda is 6 inches shorter than the XtraCycle which was exactly what I needed to fit into my building's elevator.

Gareth, you are completely right. He should be riding his own but he has special needs and we need to take special precautions when riding with him.

I was going to say a trail-a-bike as well but that sort of situation demands something very like you chose.

What about when he gets bigger?

The Adams Trail-A-Bike does have additional attachments that include a seat back and strap to help keep a kid on the bike.

What you really might want if you haven't found it yet is the Weehoo https://rideweehoo.com/products-weehoo-bike-trailers
Which the kid can pedal but is more like a lounge chair with straps for safety. There are weight limits for child seats, it isn't always that the frame, seat or rack can't carry the kid but more that past a certain weight the tail can really wag the dog if a kid chooses to struggle. Even with a trail-a-bike a shaking kid can make a fast moving bike unsteady especially under a lighter rider. From here you want to look at the family style tandem that has the adult in the back and the kid seated in front of the them cargo style, or modify a cargo bike, but it does start to get expensive.

My Solution
 

I ended up building this support cage out of PVC pipes. I used a seat I bought on Amaz and screwed it onto a Topeak rack I had. That seat also comes with folding foot rests. The PVC cage helps him stay in place and it's reinforced with plumber's glue I probably spent about $10 and it took me 6 hours total. We get tons of compliments and it solves our concern about him staying in place and not swinging sideways or back and forth.


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