excessive tyre bounce on trailer

[dnej]

What causes excessive tyre flex to occur,on a tyre that is correctly inflated.

Would the springs be over size perhaps.

Springs are single leaf type.Boat ,trailer and gear weigh about 1300kg.
Tyres are rated correctly.Maximum pressure 64psi,and these are run at 60psi,cold.

When the trailer is stationary,while in the boat,you can see the tyres flexing,when movement is created in the boat. The springs dont appear to move in the slipper.

Any suggestions?
David

[Noelm]

I guess any number of things can make a Tyre flex, but I would reckon that the Tyre is the "softest" link in the Suspension, and as such would be the first to give if some weight was applied, but it might be a different story at 80KPH and you hit a bump (maybe)

[dnej]

Noelm,
Yes,that is what I think also.At 80KPH,in the rear vision mirror,the tyre bounce,or flex is very pronounced.That is why I think it may be oversprung. Tyres giving ,but springs not.
David

[jimbo59]

Do you mean it is bouncing as you drive down the road? Some tyres develop a memory from sitting around and need to be replaced with one of a higher ply rating.

[Mr__Bean]

Sounds more like the tyre to me.

Does the tyre sit right when stationary or is the flat spot on the bottom a bit bigger than you think appropriate?

If already showing signs of stress when stationary then spring rating won't help.

- Darren

[DAVE_S]

My guess is the tyre has seperated .
run your hand around the tread and feel if there are any lumps .

[bassfanatic5]

A mate has a quinnie that was doing the same thing, it came fitted with 13'' rims fitted with light truck tyres. After 12 months he decided to step it up to a set of 14'' rims and a set of light truck tyres recommended by the local tyre shop, job fixed it doesn't have anywhere near the tyre bounce it did.

[Chimo]

David

Without seeking to teach you to such eggs ............

If you take the trailer for a spin without the boat does it ride really rough and bounce and perhaps even feed shudders into the car thru the pull?

If it does then the tyres have suffered tread separation. Age, overheating or being built by a worker with oil or fat on his / her hands will cause failure.

If the tyre moves about when your in the boat parked then perhaps the tyre pressure is too low and low pressure leads to heat which can also hasten tyre failure too.

Cheers
Chimo

[Roughasguts]

Have you got Silverstone tyres ? they turn in to the shape of an egg in no time flat. Correct tyre pressures won't help those poor exscuse for a tyre. Hell I just got rid of 4 an inherited 2 more on me boat trailer (yeah okay many years ago but the tyres are still crap)

Jack the tyres up and run a edge or pointer near the tyre tread, then spin the wheel and see if it runs true bet it doesn't, get rid of the tyres.

[FNQCairns]

A trap for new players or rough fitters is doing the eye bolt up to tight (it doesn't take that much torque to do it either) this will seriously cramp the springs style.

cheers fnq

[Angla]

I'd be a little suspect of the tyres if it were me. I have recently found that I have warped wheels from turning the tandem wheels around a tight corner of the house. The tyres are also Duro which I think are a little on the poor quality side.

Chris

[Blusta]

When I picked up a new outfit this seemed to happen to a small degree so I checked the pressure. It was about 60 psi. I dropped it to 45 and this seemed to solve the problem. Not suggesting that this is the case here.

[dnej]

Thanks everyone.
The bounce,or flex can be seen in the RV mirror,as you travel along.They act as suspension,with quite a large degree of flex.

Tyre are in good condition,no damage,no flat spots.
I think FNQ might be on the money.I will loosen them up,and see how I go.I will also crank up the pressure to the max 64psi.
How do you rate the tyres I have on.

Nankang 155R13C 8pr steel radial, 90/88L,(what ever that means) light truck.
2 ply side walls,2 ply tread area,rated at 1320 lbs per wheel,at 64 PSI.

Got Liz to jump and down in the boat,after I greased the top of the slipper,and they move back and forth OK.
How much space should there be from the end of the spring,to the stopper?
Thanks Again
David

[Mr__Bean]

David,

At 1320 lbs (600kg) your tyres are rated below the 1300kg you are carrying.

I suspect that they are ballooning.

I went out and had a look at mine they are 2 ply sidewall and 4 ply tread, rated at 850kg each tyre on a single axle and 800kg each tyre on a tandem.

Do you tow far?

If so then it might pay to get 6 ply tyres.

- Darren

[Chimo]

David

I had 4 of this brand of tyre and had to replace them all due to tread separation / delamination issues.

It was not all that obvious even with between 50 and 60 psi when the boat (Vagabond = heavy) was on the trailer. With the trailer empty and travelling at between 30 to 80 kph on smooth GC roads the trailer nearly shook both the Patrol and the Fairmont like crazy.

When my wife towed the empty trailer before I did, to be honest, I thought she was being dramatic. She wasnt, do not replace them with the same breed, they are cheap and thats why trailer manufaturers fit them in the first place.

Chimo