Double axle trailer suspension question

[Chrisrog]

How do double axle trailer suspension systems work? Do all 4 wheels take the load equally, or does the back axle load first to some point prior to additional load being taken by the front axle? How does the tongue height factor into this? Does a high tongue add load to the rear wheels?

Had my first trailer tire blow-out this weekend and was surprised the rear wheel was almost completely on the ground after the sidewall was shredded. The front wheel was carrying the entire load.

[SilentSeven]

There are two or three benefits of a double axle trailer

- Improved tracking via the pair of inline wheels
- Less load per tire - the trailer can support higher weights as you not as close to the max weight of the tire.
- Improved braking - assuming you have brakes on all 4 wheels and they work.

All this comes as a cost...

- more weight
- more expense
- less maneuverable

Generally, I like double axle trailers for over the road towing but prefer single axle for short haul. Too bad you can't have both. I think with the bias these days to larger boats, single axle trailers are becoming the exception and reserved for 19 foot tourney boats.

Regarding your question, there's some suspension geometry questions that come into play. If your trailer has a shared shackle system, the load on the front and rear axles will vary based on the tongue height. I don't think it's that material as long you work within the designed tongue height range of the trailer. When you had your blowout, what did you expect? I pretty much would have expected what you saw - the blown wheel would sag and maybe even drag. However, as a) it'a solid axle b) the leaf spring will only allow limited droop, it's not surprising that it didn't drag the rim. I look at this as a feature, not a defect.

Ok, enough blabbing on trailers....not sure this even answered the question.