On a Thule Chariot Trailer (back when sold as Trek), it came with the plastic wheels. I got it second hand so I assume the tires are stock. The tires are rated for 55 psi, but they slip off the wheel and cause blow outs (both out and about as well just sitting in the garage). This happens on any of the wheels. I can not find any damage to the wheel or the tire, so my current work around is using around 35 psi.

Has my tires aged too much? It has been garage kept. While the tires do have some cracks in the tread, they hold up really well. The sidewalls are kind of stiff so I can stroller around with it easily without air (these wheels have blown out on me in public before). I notice that the tire is a bit more shiny than any of my newer ones. Would replacing the tires with new ones prevent this from happening?

Is a wheel change in order? I see that the current models use conventional wheels. The plastic wheels don't really bother me personally. They are the side post quick release, with the release mechanism on the trailer itself and not like a push button in the wheel hub.

Side Profile

  • Just clarifying - they're plastic rims on normal spokes with a normal hub? Or completely plastic one-piece rim+spoke+hub? Either could have a wheelchair stub axle fitted.
    – Criggie
    Commented May 3, 2017 at 1:15
  • @Criggie, it is a one-piece wheel (and upon exploring around SE) assume it is a wheel chair axle.
    – BPugh
    Commented May 3, 2017 at 14:41
  • I added a picture of the trailer (this isn't a photo of mine, but it is the exact same model).
    – BPugh
    Commented May 3, 2017 at 14:49
  • The number on the side of the tire is essentially arbitrary. Just go for a properly inflated tire.
    – Batman
    Commented May 3, 2017 at 14:54

2 Answers 2


It's the plastic wheels. Most mag(composite or plastic) wheels are only rated for 40 psi, no matter what the tire says. No need to change out for metal wheels as long as you are happy with the trailer.

  • There's also a vague possibility that the plastic wheels have deformed, due to be storing in too-hot conditions with high pressure in the tires. Commented May 2, 2017 at 23:57
  • A harder tyre helps with rolling resistance, and comfort only matters if the load is kids. On the other hand, a super hard tyre with a light/unloaded trailer is awfully bouncy and is more likely to flip on a corner or pothole.
    – Criggie
    Commented May 3, 2017 at 1:13

Just something you may want to check: Sometimes the stock tires wear down and expose the wires along the sidewall. These may keep it from holding air if it's tubeless or inflict punctures in the tube. I have a two-wheeled cart/wheelbarrow that this happened too and it took two tubes (one in a spectacular blowout) before I realized the issue and had to replace the tire. Plastic/fiberglass wheels in this case as well.

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