Tyre load infomation.

[toffo24]

I see that a lot of people are looking to reduce their tyre sidewall height size to achieve a different stance, here is some information that should help you when you look at downsizing.

Just worth thinking about so you know.

Originally as size of you may know our busses were vans or mini busses, when there were produced the only tyre that was made was a cross ply(nylon belts) tyre. After 1971 all t2's were produced with steel belted radial tyres. The original radial tyre specification is a 185R14 C or for mini buses 185SR14 reinforced.


Any change away from the original tyre size needs to take the following into account.

Load index

The axles on out buses have a set capacity, most of the time you will not need to load you vehicle up to this capacity, although it should be taken into consideration that loads increase under cornering, accelerating and braking.

If you want to check the information I used then it's here below:-

http://www.reocities.com/motorcity/garage/6369/Camper_dades_tecniques.htm" onclick="window.open(this.href);return false;
campmobile
Front axle load is 1010kg
Rear axle load capacity is 1270kg

All modern tyres now have a load/speed index marked on the sidewall of each tyre,

The table below sets this out for you:-


http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35" onclick="window.open(this.href);return false;


So you how do you work out which ones right for you?

Take your axle capacity and divide it by the amount or wheel assemblies fitted to it, in our case 2

So 1010kg divided by two is 505kg per tyre

Go back to you chart and you will see that this is equal to the Load index of 85 and 515 kg per tyre. Now personally I would always allow an extra 50% capacity in any load capacity change so it would be a good idea to bear this in mind if you are changing your tyre specifications away from the original tyres

You can use the chart to check if your new tyre choice would be within the original capacity
limits

I hope this may be of use.

 

[AndyO]

Thanks Toffo for posting the above, I have a couple of questions that I would like add to this thread, namely:

Original radial tyre specification is a 185R14 C - how do you calculate the profile?

Toffo already responded on another thread: Thats 82% of the nominal section width in mm which in this case is 185

I don't understand that I'm afraid, as 82% of 185 = 151.7mm?? Web search stated it's 80 (some say 82).

What would be the profile of a 175R14C?

With standard ET 39, 5x112 PCD 14" x 5.5J Rims (71> Rims) I guess a 185 tyre is advised, what if you want to go narrower, say 175 or 165 even, what sort of issue would this create, if any?

Personally I need a lower profile tyre, esp on the front as I'm lowered 3 to 4", but still wanting to ensure that I have a good load rating. Safety is of course a concern, but also with a stiffer sidewall handing is maintained (or improved, if like me you have spongy car tyres on). As such I am at the moment planning to:

Retain the 186r14C tyres on the rear.
Drop to either 185/65 r14 or 175/65 r14 on the front.

The only option I can find with a reasonable load rating in a 185/65 r14 on the front is the Nokian at a 90 (600 KG) load index.

However it seems that there are 'loads' (no pun intended) if I go for 175/65 r 14, as follows:
http://www.camskill.co.uk/m90b0s510p0/Van_Tyres_-_Trailer_Tyres_-_Caravan_Tyres_-_Motorhome_Tyres_-_Minibus_Tyres_-_14_inch_R14_inch_-_175_65_14_175_65R14" onclick="window.open(this.href);return false;

 

[creationblue]

I researched this lots recently and went for:

185/60R15 T continental vanco contact2 up front

195/70R15 T conti vanco contact2 (97) rears

This gives me as near as damn-it the radius as stock which keeps my gearing up with a good look (for me anyway) on the front. The vanco's are reinforced and drive nicely with the stiffer side walls over the 185 75 14s I had before

 

[r73]

I researched this lots recently and went for:

185/60R15 T continental vanco contact2 up front

195/70R15 T conti vanco contact2 (97) rears

This gives me as near as damn-it the radius as stock which keeps my gearing up with a good look (for me anyway) on the front. The vanco's are reinforced and drive nicely with the stiffer side walls over the 185 75 14s I had before

Sounds like research well done - decent load rating does mark for a much better ride and vancos are quality.

 

[toffo24]

I don't understand that I'm afraid, as 82% of 185 = 151.7mm?? Web search stated it's 80 (some say 82).
Hope this help you Andy , if you take a tape measure you will find that if you measure from the rim to the top of the side wall you will find it come to about 15.1 cm

What would be the profile of a 175R14C?

With this tyre the rule is the same 82% of 175 mm(although almost all modern tyres mark up tyres 80 as an aspect ratio or sidewall height)

With standard ET 39, 5x112 PCD 14" x 5.5J Rims (71> Rims) I guess a 185 tyre is advised, what if you want to go narrower, say 175 or 165 even, what sort of issue would this create, if any?

Depending on how narrow you wan to go the narrower the tyre will create an issue as each tyre size has a permissible rim with, in. The case of the 175 Has an suggested rim of 5-6.5J 14 rim so a minimum of 5 inches wide up to a maximum of 6.5 inches wide.


Please see attachment

http://www.alloywheels.com/Tyre_Calculator" onclick="window.open(this.href);return false;

Personal , try to stay with a commercial tyre if possible , I hope that you now have the information that you require, any other issues get in touch.

 

[yachty]

I researched this lots recently and went for:

185/60R15 T continental vanco contact2 up front

195/70R15 T conti vanco contact2 (97) rears

This gives me as near as damn-it the radius as stock which keeps my gearing up with a good look (for me anyway) on the front. The vanco's are reinforced and drive nicely with the stiffer side walls over the 185 75 14s I had before

Just to ad to this, I've also recently looked into tyres for my 71 and found Continental Premium Contact 2's for the front in 185/55/15 XL which have an 86H rating. The XL means they have a reinforced sidewall. You can also get Premium contact 5's in 195/65/15 XL for the rear which have a 95H load rating. I've bought both for my bus but can't give any feedback on them until the resto is finished

 

[Steenfeldt]

If any of you guys have an IPhone or IPad, there is a app called tire calculator

 

[AndyO]

Interesting, should have paid more attention to the fact that the profile is a ratio, aspect ratio. There's me thinking that all '65's were the same sidewall height.

I've gone and ordered 175/65 r14:

Hankook Tyres / Van / Hankook RA18 Vantra LT Hankook RA 18 - 175/65 R14 C 90T TL

I now think these may be too small - ****, I best cancel my order.

 

[sparkywig]

Have a read through this, contains everything you need to know about wheels and tyres.

http://www.carbibles.com/tyre_bible.html" onclick="window.open(this.href);return false;

 

[mattd1984]

Some good information guys.

I went for

Rear - Pirelli P1 Cinturato 185/65 R15 T (92), Reinforced
Front - Pirelli P6 Cinturato 175/55 R15 H (77)

Should probably have gone for something with a higher rating for the front.

 

[AndyO]

Have a read through this, contains everything you need to know about wheels and tyres.

http://www.carbibles.com/tyre_bible.html" onclick="window.open(this.href);return false;

Bloody hell - indeed all you need to know and more - especially like his latest blog entry on the right hand side.

Cancelled the tyres - now at square one...but better informed of course.