TYRE COMFORT

[T6AL]

Hi Im considering buying some Devonports for my T6 150 LWB Shuttle but most of the sets on offer have 215/60 continentals with a load rating of 107/109 which I don't need. I am a little concerned about the ride comfort with these tyres and wondered if anyone has any experience with this combination .
Thanks

 

[andys]

Hi Im considering buying some Devonports for my T6 150 LWB Shuttle but most of the sets on offer have 215/60 continentals with a load rating of 107/109 which I don't need. I am a little concerned about the ride comfort with these tyres and wondered if anyone has any experience with this combination .
Thanks

I have this combination on mine, they may be a bit over the top in spec for us (made to cope with all up to T32) but the comfort is fine don't worry about it

 

[T6AL]

Great thanks for your advice.

 

[Davenjo]

My understanding (happy to be corrected if my understanding is wrong!) is that, regardless of how much weight you carry, the load rating of the tyres must be capable of carrying, as a minimum, the maximum permissible axle weight of the vehicle; in my case (T30) I have 105/65 tyres rated at 105/107 (925kg - 975kg) so, with permitted axle weights of 1600kg and 1625kg, I could probably come down a couple of indices but have no intention of doing so. Comfort wise they are OK but you do feel the bumps in the road - I think this is as much to do with the 60 PSI they are running at than anything else. I do worry about getting stuck on campsites with such skinny, high pressure, tyres but, so far, have always managed to get off.

 

[PukkaT6]

My set were great, for the 25 miles I had them on the van lol

 

[chriscroft]

My understanding (happy to be corrected if my understanding is wrong!) is that, regardless of how much weight you carry, the load rating of the tyres must be capable of carrying, as a minimum, the maximum permissible axle weight of the vehicle; in my case (T30) I have 105/65 tyres rated at 105/107 (925kg - 975kg) so, with permitted axle weights of 1600kg and 1625kg, I could probably come down a couple of indices but have no intention of doing so. Comfort wise they are OK but you do feel the bumps in the road - I think this is as much to do with the 60 PSI they are running at than anything else. I do worry about getting stuck on campsites with such skinny, high pressure, tyres but, so far, have always managed to get off.

I think you are right. If I didn't need to be carry a full load, I would down air, if i wanted to improve the ride. I run our 235/60/17 load rating 106 at 48psi rear, 44psi front, which is fine for our loadings, and much better ride and straight line stability. The steering was greatly improved, although it won't help economy

 

[PukkaT6]

What should i have? Got sportlines and all on 49psi

 

[chriscroft]

What should i have? Got sportlines and all on 49psi

Depends on your maximum axel loadings. Have you ever had your loaded van on a weigh bridge? What are your tyres maximum loads?, and maximum pressures?
A really good way to judge is the bulge in the side walls with your max load. Ideally you will have the same bulge profile front to rear.
Please don't hold me to this as it is a very rough guide. If a specific tyre will take 850kg at 60 psi; and lets say 500kg at 30psi (a car loading); then pro-rata if your actual axel load was 1400kg=700kg per tyre the pressure need would be: for every 1kg above 500kg you would need an extra (60-30/850-500) = 0.0857psi; so 700-500=200kg of extra loading*.0857= 17psi + 30psi = 47 psi. This is very rough, I have seen a better equation somewhere on the internet, but I cannot find it now.
There is another method using a tray of wet sand underneath the tyre, then measuring the impressed contact area of the tyre compared to axel weight, but that is only for serious experimentors

 

[PukkaT6]

Jesus my melon is fried reading that lol

Its a T32 kombi which never has anything in it lol

 

[chriscroft]

Jesus my melon is fried reading that lol

Its a T32 kombi which never has anything in it lol

It is a bit much for late night reading
My tyre pressures of 48rear/44front sound about right then 0r maybe 44psi all round. Check for similar bulges in the side walls all round, you can even use a straight edge and tape measure.

 

[chriscroft]

 

[chriscroft]

Here it is

https://tzlee.com/blog/2011/03/tyre-pressure-calculation

Hope it helps.......

 

[PukkaT6]

Thats sent me under ha

 

[chriscroft]

Thats sent me under ha

me to

 

[Dave Coughlan]

Looks like 44 front and 36 back for Mty T30 on 17/18"



View attachment 13477

 

[chriscroft]

Looks like 44 front and 36 back for Mty T30 on 17/18"

View attachment 13478

View attachment 13477

That's pretty much where I am pressure wise. It gets a bit more tricky when you move away from standard wheel/tyre sizes, that aren't reflected on the jamb sticker