Ride "quality" on unsealed roads

[greymad]

Administrators: If this topic has been covered elsewhere then by all means please accept my apologies and deal with it as best you see fit.

I recently did some distance on what I would call fair to reasonable dirt road.
The vibration/noise/harshness was something horrendous.
I'm hoping it can be alleviated (in whole preferably, 'though that might be expecting too much) when I eventually come to change tyres, which are currently the 235/55 R17 Dunlops.
The placarded pressure is 44psi (front). Next time I go off bitumen on a similar road surface I'll be dropping the pressures, but one wonders how far can that go?
Any comments please?

Secondly: while I'm quite happy with the road noise on bitumen surfaces, there's a lot of "bump-thump" reaction when passing over manhole covers, train line crossings, etc. Again this would be reduced a little by lowering pressures but I don't want to ruin the tyre life by wearing out the outer edges prematurely.

Maybe the 44psi recommended is too high? What do you folk out there use - what experience have you had over a longer mileage than I've done (17,000km only, so far...)

Any tyres out there which are significantly smoother and quieter (particularly off-bitumen)?

Thanks ...

[Ivo]

Drop them to 30psi and feel the difference. The tyres will not roll of the rims and the van will not tip over at first sign of a bend in the road. You will just get a smoother ride.

Actually, best bet it to take a tyre gauge with you and experiment by dropping the pressure by 2psi per go and see how it improves the ride.

[BrianJ]

I agree with 30-35psi on unsealed roads, but I had been using 45psi for normal use which gives a reasonable ride, but found that the outsides of the tread were wearing too much, so I am running 55psi front and 50psi rear on a trip I am doing with a medium sized load of equipment.

I would also say that the ride of mine has improved gradually after it got to about 100,000km and the suspension has loosened up a bit. (run in).

Brian

[Transporter]

Droping the tyre pressure does help but also consider the higher profile tyres like Good Year Cargo Vector, 215/60R17, they will go on my T5 in next month or so, replacing the Kumho Solus KH15 that didn't last 20,000km with the tyre rotation every 5,000km.

[MultiplexMan]

I run 52 psi all round and don't have "ride issues". Noise is at passenger car standards and does not intrude. I am running 16" steel wheels.

I tried 17" wheels but prefer 16" for ride quality.

I do a fair bit of unsealed road driving but avoid heavy corrugations.

[greymad]

I run 52 psi all round and don't have "ride issues". Noise is at passenger car standards and does not intrude. I am running 16" steel wheels.

I tried 17" wheels but prefer 16" for ride quality.

I do a fair bit of unsealed road driving but avoid heavy corrugations.

*Ours is a 132kw motor which comes with the larger diameter brake discs at front: are you saying that 16's will fit ok in place of the 17's?
*If you're running 52psi and don't have a ride issue then there's either something radically different with the suspension on your vehicle, or else with what you & I regard as a tolerable ride. But thanks anyway.
*Transporter ... thanks for the heads up on the Khumos (what a bargain...NOT). I'll get back to you when you've got some idea of the Goodyears you're about to try.

[Transporter]

I doubt that 16" wheels will fit on yours.

[MultiplexMan]

@Transporter - Correct 16" will not fit.
@ greymad - sorry, my experience doesn't help you

I drive a Kombi Beach. I think the suspension is different from normal as I have parked alongside a standard T5, a Multivan and a 4Motion. My Beach definitely sits higher - even with the bull bar fitted and a full load. I checked my vehicle build codes and it should have stock suspension but

I spend a lot of time in Workmates and Defenders. I know what a rough ride is

[greymad]

@Transporter - Correct 16" will not fit.
@ greymad - sorry, my experience doesn't help you

I drive a Kombi Beach. I think the suspension is different from normal as I have parked alongside a standard T5, a Multivan and a 4Motion. My Beach definitely sits higher - even with the bull bar fitted and a full load. I checked my vehicle build codes and it should have stock suspension but

I spend a lot of time in Workmates and Defenders. I know what a rough ride is

Yep - that's what I figured re the 16 vs 17 inch wheels...
...and after 23 years driving Landcruisers up in the Cooper/Eromanga Basins I too, have a good idea of what constitutes a rough ride(!)
Thanks again for the feedback guys... looks like a kidney belt & noise cancelling headphones for the immediate time being.

[Cousin]

Hi greymad, I'm on my fourth VW. Mark iv Golf, two T4 transporters and now a T5 Multivan
They've all suffered from 'crash' suspension, compared to other makes
That is, they 'crash' over sharp bumps, such as railway crossings
You do get used to it, and in fact if I hadn't read this complaint from motoring writers on numerous VWs', might have thought the vehicle I had was faulty as well
But perhaps might be worth getting your shockers checked
Get a bit of air in them, or broken mount or any number of other things, they will bang and crash around much more


M

[greymad]

Hi greymad, I'm on my fourth VW. Mark iv Golf, two T4 transporters and now a T5 Multivan
They've all suffered from 'crash' suspension, compared to other makes
That is, they 'crash' over sharp bumps, such as railway crossings
You do get used to it, and in fact if I hadn't read this complaint from motoring writers on numerous VWs', might have thought the vehicle I had was faulty as well
But perhaps might be worth getting your shockers checked
Get a bit of air in them, or broken mount or any number of other things, they will bang and crash around much more


M

Thanks Cousin .. the word "crash" certainly describes what I'm experiencing - and surely after 15 months and a mere 17,000k's the shockers should be near brand new: almost all driving so far has been on tarmac.
I'm of a generation which was brought up on crossply tyres, and anyone who hasn't ever driven a car on s**t roads using those will never understand just how different (especially how smoother/quieter) they are cf radials.
It's being a bit old fartie to say so, but there seems to be nothing more stressed these days than roadholding capabilities - over all else.
And as for 35 profile tyres on a street car? ... absolute w**k. Here endeth the sermon.

[Transporter]

In my 4Motion T5 the left rear shocker was leaking and was replaced under the warranty. They were Monroe made in Belgium. Later I've replaced both of them with Pedders HD shocks and King Springs. I can't complain, now almost at 100,000km and 7 years later, even on a bit rough road I'm happy with the ride. Tyres pumped to 51PSI at all the time.

Check the shocks for any sign of oil leak on them, you will see it as a wet patch at early stage.

[greymad]

In my 4Motion T5 the left rear shocker was leaking and was replaced under the warranty. They were Monroe made in Belgium. Later I've replaced both of them with Pedders HD shocks and King Springs. I can't complain, now almost at 100,000km and 7 years later, even on a bit rough road I'm happy with the ride. Tyres pumped to 51PSI at all the time.

Check the shocks for any sign of oil leak on them, you will see it as a wet patch at early stage.

Check your PM's ... I think we need to get together & compare vehicles.
We're not so far apart ... Eden Hills/Flagstaff Hill. Cheers...

[greymad]

Well... a very interesting experience in a Multivan over the weekend. Noticeably quieter and softer than our van.
I'm wondering if, as our camper is based on a commercial vehicle, the spring rates are higher (ie stiffer).
Admittedly the Multivan is a SWB, so the other one to use as comparison would be a Caravelle, but then too, ours is a 132kw 4motion so whether the springs are altered along with those options...who knows?

[Transporter]

In the 4motion you have extra transfer case (bevel gearbox), drive shaft from it to the rear diff and 2 more drive shafts from the diff to the wheels; all that is missing on 2WD vans. This alone will make more noise.

The other thing to remember is that the insulation level from the factory could be different in the Multi and Caravelle.