Tyre size and Handling

[Johnnyv]

I currently have 185/55R14 tyres fitted. My camper is all over the place. Should I change to 185/80R14 ?
Thanks
John

 

[Clem]

Is your van lowered at all?

 

[sparkywig]

Hello John, welcome to the forum.
When was your last MOT?
Check the rubber steering coupler and then all the steering joints (idler arm, drag link, track rods, etc) and steering box for play.

 

[Johnnyv]

I think it has dropped spindles and MOT was all ok last week.

 

[sparkywig]

The tyres alone won't cause the wandering issue, it's a combination of things unless it happened suddenly.

 

[fallingoffalot]

Is the handling just bad in cross winds? If so try pumping them up more, I had similar tyres when I got my bus in 2019 and they had about 32psi in and cross winds were a real problem, after I put like 42 in the handling was better. The solution I have now is van tyres on rear and 4x4 tyres on the front. There are quite a few threads on this here.

 

[BillS]

Interesting thread, I have improved it but not sorted it out altogether yet, but have checked the tyres and they are dated 2004 so they are next on the list. I found the steering box needed adjustment, must be done in the straight ahead position. This is because the high point is at the straight ahead position, the box is designed to have play either side of this point. Once I had done this, most important discovery, I found that the bus had had its tracking done to one side of centre of the steering box. It was obvious because the wheels where pointing to one side with the box centred, so when the wheels were lined up the steering box was at a point of great play hence the wandering. Hope this makes sense, let me know if more info is of interest, best of luck

 

[Clem]

I think it has dropped spindles and MOT was all ok last week.

Hard to call without seeing/more info, but running 55 profile tyres on 14" rims probably isn't doing any favours - are they on the back too? That will be affecting the gearing negatively.
As others have said, ball joints, steering coupling, steering damper, tyre pressures, tie rods will all have an effect. Dont assume a fresh MOT will means everything is fine - as much as people state that MOT tests are vital on MOT exempt vans, many test stations don't have a clue about old buses.

 

[naskeet]

I currently have 185/55R14 tyres fitted. My camper is all over the place. Should I change to 185/80R14 ?
Thanks
John

I would seriously question whether any 185/55 R14 tyres, have a close to adequate load rating for a 1968~79 VW Type 2 front axle, which should be at least a minimum of 505 kg for each tyre!

 

[Bluesnailman]

Post in thread 'White knuckle driving'
https://earlybay.com/threads/white-knuckle-driving.79760/post-638933

my research on tyres, side walls, plus and pressures took me to this conclusion. I had commercial Continental Vanco tyres before and this set up is loads better. In fact, really good I’d say. The steering etc needs to be right as a starting point of course. I also fitted a thicker anti roll bar a few years ago. 50mph side winds are still be be avoided however…..

 

[Clem]

The load rating arguments have been done to death. They wont be making the van veer about, so lets focus on that? Cheers

 

[NigelDenham]

Interesting thread, I have improved it but not sorted it out altogether yet, but have checked the tyres and they are dated 2004 so they are next on the list. I found the steering box needed adjustment, must be done in the straight ahead position. This is because the high point is at the straight ahead position, the box is designed to have play either side of this point. Once I had done this, most important discovery, I found that the bus had had its tracking done to one side of centre of the steering box. It was obvious because the wheels where pointing to one side with the box centred, so when the wheels were lined up the steering box was at a point of great play hence the wandering. Hope this makes sense, let me know if more info is of interest, best of luck

I had exactly the same..much better once centred and adjusted

 

[static]

My bus also used to do the Watusi when driving down a road. Doesn’t do that anymore.

It’s invariably more than just one problem.

It’s a combination of problems: the steering box, tyres without reinforced sidewalls and especially the steering coupling disk.

Start with steering coupling disc and don’t be thrifty here: the inexpensive ones are pure *****. Paruzzi (and a few others) have the correct one.

 

[kjb01]

My Van had 185/60/14 when I got it.
Input 185R14c on it.
What is the lowest profile I could put on without compromising the gearing etc on standard wheels?
Driving wise mine is fine, it’s lowered on an adjuster and turned the splines on the back.

 

[sparkywig]

Exactly what you've fitted, 185R14C. They're the closest to the original tyre size as it left the factory.

 

[naskeet]

My Van had 185/60/14 when I got it.
Input 185R14c on it.
What is the lowest profile I could put on without compromising the gearing etc on standard wheels?
Driving wise mine is fine, it’s lowered on an adjuster and turned the splines on the back.

Overall effective gearing is dependent upon transaxle gear ratios & final-drive ratios, plus wheel-diameter, tyre section-width & tyre aspect-ratio. With tyres of the same nominal section width, using a lower profile than 185/80 R14C on a 14 inch wheel or 195/70 R15C on a 15 inch wheel or 195/65 R16C on a 16 inch wheel, will increase the overall gearing, resulting in higher engine revs for a given true road speed and the speedometer with give a higher reading for the same true road speed.

 

[Ben72Bay]

I’m running this:
175/55/15 front
195/65/15 rear.
40psi all round.

New shocks helped massively and a steering box refurb and new rubber coupler