Tyres

Any Land Rover related info can be posted here.
User avatar
AR4412
Maître Pâtissier
Posts: 8917
Joined: Thu Sep 22, 2011 9:31 am
Location: Bedford

Re: Tyres

Post by AR4412 » Thu Jun 15, 2023 8:37 pm

Then you are in luck,, as one marked 940 is a KMH speedometer for 7.50" tyres IIRC. (And my maths is right.). The other numbers I mentioned are for MPH speedometers.

940 refers to the number of turns of the wheel per kilometre. Roughly equivalent to 1408 turns of the same wheel per mile.

Regards,
For Those That Have Had To Fight for It, Life Has Truly A Flavour The Protected Will Never Know.

'First my weapon. Then my equipment. Then myself.'

Neil.

09FM98. 1973 Ex SIII FFR Now 3.5 V8 LWT Coiler.
55HG98. 1980 SIII FFR PARA RECCE. Ex 1, 2 and 3 PARA.
Td5 90 XS.

User avatar
weetchus
Pastry Chef
Posts: 676
Joined: Wed Aug 15, 2018 3:15 pm

Re: Tyres

Post by weetchus » Fri Jun 16, 2023 7:11 pm

Thanks for all the great feedback.
How confusing did the tyre manufacturers have to make it? I thought the 75R16 would be 7.50 and the 85R16 would be very different, like 8.50 :lol:
Okay, so when I get tyres I'll probably go with a locally available:

Westlake SL369 245/75R16 AT terrain
I'll mainly be on roads and tracks - not deep mud or rock climbing!

https://www.amazon.com/Westlake-SL369-O ... B00VLYTU96


AR4412 wrote:
Thu Jun 15, 2023 8:09 am

The 235/85 R16 is about the closest to a 7.50" tyre in overall size comparision, but they do vary slightly between manufacturers.

Ridgy
Pastry Chef
Posts: 676
Joined: Fri Oct 03, 2014 12:35 pm
Location: Essex

Re: Tyres

Post by Ridgy » Sat Jun 17, 2023 7:30 am

Hi Alex.

The modern tyre sizing is weird because it's a mixture of imperial and meric. In your example of 235/75R16, 235 is the width of the tyre in mm; 75 is the profile (aspect ratio) as a % of the width i.e. The depth of the tyre is 75% of 225mm; and the 16 is the wheel diameter in inches.

Thus the smaller the aspect ratio the lower it sits and the smaller the circumference for a given width e.g. A sports car might have 40 profile tyres which look more like rubber bands round the rim.

There are also other bits on the tyre code which are beyond me but indicate things like max speed and weight ratings.

The older designations like 750x16 come from the crossply days AFAIK when a tyre was just a tyre and didn't come in varying aspect ratios - someone will correct me I'm sure but I think they were more of less standard at around 85%.......

Hope that helps.

Steve
57 KB 58 1983 SIII GS Lightweight

User avatar
weetchus
Pastry Chef
Posts: 676
Joined: Wed Aug 15, 2018 3:15 pm

Re: Tyres

Post by weetchus » Sun Jun 18, 2023 11:15 am

Steve, that helps a lot. Thanks.
The aspect ratio bit was the confusing part but now I've got it.
I'll take a look at 235 and 245 to see what works and is available here. The 85 might be a good plan if you say the original 75R16 ply were about 85% aspect ratio.

I'm after something that looks in keeping with the original size but with a touch more aspect ratio and width.

User avatar
Jamie
Posts: 200
Joined: Sun Jun 03, 2012 11:45 pm
Location: Chesterfield

Re: Tyres

Post by Jamie » Wed Nov 08, 2023 3:05 pm

AR4412 wrote:
Thu Jun 15, 2023 8:37 pm
Then you are in luck,, as one marked 940 is a KMH speedometer for 7.50" tyres IIRC.

940 refers to the number of turns of the wheel per kilometre.

Regards,
Any idea what 920 would mean Neil?

I have a 1983 lwt currently with 205/80 R16 fitted. I want to replace these with 6.50's or 7.50's.

Thanks
Jamie

User avatar
AR4412
Maître Pâtissier
Posts: 8917
Joined: Thu Sep 22, 2011 9:31 am
Location: Bedford

Re: Tyres

Post by AR4412 » Wed Nov 08, 2023 4:46 pm

Hi Jamie,

A 920 KMH speedo would if I got my math right, be equivalent to a 1472 MPH speedo, which wasn't I believe a Land Rover option. (If I'm wrong, I'm happy to be corrected.)

Can you see the Serial Number on the Speedo face? Might be able to track it's original fitment from that. The tyre size would be equivalent to around a 7.0"x16.

Regards,
For Those That Have Had To Fight for It, Life Has Truly A Flavour The Protected Will Never Know.

'First my weapon. Then my equipment. Then myself.'

Neil.

09FM98. 1973 Ex SIII FFR Now 3.5 V8 LWT Coiler.
55HG98. 1980 SIII FFR PARA RECCE. Ex 1, 2 and 3 PARA.
Td5 90 XS.

User avatar
Jamie
Posts: 200
Joined: Sun Jun 03, 2012 11:45 pm
Location: Chesterfield

Re: Tyres

Post by Jamie » Wed Nov 08, 2023 8:35 pm

Hi Neil, thanks. I'll have a look tomorrow and get back to you.

Regards
Jamie

User avatar
Jamie
Posts: 200
Joined: Sun Jun 03, 2012 11:45 pm
Location: Chesterfield

Re: Tyres

Post by Jamie » Thu Nov 09, 2023 5:35 pm

Hi Neil

Here is the front on my speedo if you can make sense of that.
IMG_0162.JPG
IMG_0162.JPG (3.28 MiB) Viewed 2057 times
Thanks
Jamie

User avatar
AR4412
Maître Pâtissier
Posts: 8917
Joined: Thu Sep 22, 2011 9:31 am
Location: Bedford

Re: Tyres

Post by AR4412 » Fri Nov 10, 2023 9:30 am

Hi Jamie,

I tried finding that Speedo last night, but even the Smiths/Jaeger lists I found don't list an SNT 6209-45 speedometer. I did find some other applications that had a KMH '920' Speedo, but no Land Rover speedo's on the lists.

I looked into the optional parts catalogue as I was sure I had previously seen a 7.00x16 tyre in there, and I had.
IMG_20231110_084935.jpg
IMG_20231110_084935.jpg (1.9 MiB) Viewed 2048 times
So I looked a speedo options to see what was there.
IMG_20231110_084729.jpg
IMG_20231110_084729.jpg (1.98 MiB) Viewed 2048 times
We just need to find images of, or info on, the KMH ones to see if one matches yours.

Regards,
For Those That Have Had To Fight for It, Life Has Truly A Flavour The Protected Will Never Know.

'First my weapon. Then my equipment. Then myself.'

Neil.

09FM98. 1973 Ex SIII FFR Now 3.5 V8 LWT Coiler.
55HG98. 1980 SIII FFR PARA RECCE. Ex 1, 2 and 3 PARA.
Td5 90 XS.

User avatar
Jamie
Posts: 200
Joined: Sun Jun 03, 2012 11:45 pm
Location: Chesterfield

Re: Tyres

Post by Jamie » Fri Nov 10, 2023 2:24 pm

Thanks Neil, I appreciate you looking. It is possible the speedo has been changed out by a previous owner but from what I can see of its history the mileage looks genuine.

These things are never straight forward. I posted a question on the Facebook lightweight group asking what the original tyre size would be for a 1983 lwt and I thing the general opinion was 7.50's... but who knows for sure. I actually prefer the larger tyre. I'm currently looking at some Deestone 7.50 x16's.

Again, thanks for your help, any info will be appreciated.

Thanks
Jamie

Post Reply