The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Rims & Tires

Hi,

last week I got my C-20. It has 17" rims since the tires say 255/70R17. Chevy C-20 Picasa - Are these stock rims for the 1965 C-20? I need to put on new tires and wonder if I can go with 275/65R17 due to the rim width. Can anyone help me?

Best greetings from Germany

Welcome to you and your C-20. Someone will surely chime in with answer to your tire/rim question. I do not know the answer to that. As far as your picture question, Provide a link to a photobucket (or other photohosting) site. We will be able to look at pictures that way.
HB

Many thanks! I found picasa the right thing for uploading photos. The link works. Now I hope someone can help me...

Joern

Joern,

You can get info on your trucks original options from the GM Heritage site. The link is.... Vehicle Information Kit

Great! That's what I need...

Thanks!

Wilkommen, Jörn. My '61 C20 has 245/75R16 tires. Not original, but gives it a nice stance, in my opinion. That's a beautiful truck!! Bet it gets lots of looks.

Nice shop....nice truck!

Thanks!

Most people here in Germany haven't seen such a truck yet wondering what it might be. When I tell them about its origin people are astonished...

I had to wait a couple of years until I was able to buy one because I had to drive 80mls to work every day. Now I have just moved and also have the place to keep it safe and dry through winter time. I always wanted a V8 with manual transmission and 127" wheelbase fleetside. Now I own one!

I need to rebuild the complete wiring in the front and back and the synchro of the transmission doesn't work. When I try to shift into 2nd gear it cracks, shifting back from 3rd to 2nd is nearly impossible. I hope to find the right parts for this problem...

The 255/70R17 are ok, but I have a new set of 275/65R17 left over from my previos truck. I hope they will fit on the rims since the circumference is nearly the same.

Jörn,

Here is a link to myhotrod.de's link page. It lists several sources for parts for these old trucks. We have a link to their site under LINKS > CLUBS > EUROPE on this site. Hope you continue posting here, but I thought these guys could help with parts a little closer to you.

Best of luck, and keep us posted!

You may want to reconsider using those tires. Most likely, they are a P rated tire, way underrated for load capacity for a 3/4 ton truck. You really should look into an LT rated tire, at least a D or E load range. Even the weight of the bare truck might be a bit much for a P rated tire.

Husker,

thank you for that link. I will definitely continue posting here. Help from my truck's country of origin is absolutely invaluable!

Longbox,

here in Germany the load range for truck tires is way different. The minimum I can get in this size is more than enough needed for the 3/4 ton trucks. The question is if these tires were originally mounted since I cannot really check the speedo. The needle has gone. I consider to get a set of American Racing AR23 which are only available in 16x8. I think they look great and the tires for them according to the current size are 30% cheaper.

***

By the way, I hope my english isn't too bad for you?

Greetings
Joern

Jörn,

You're welcome for the link. Your English is excellent, btw (by the way).

Husker (Carol)

I think someone may have misinformed you about how tire load ratings are figured. The system is pretty much universal, as virtually all tire manufacturers use the same ratings, regardless of where they are sold. I'm thinking that you're looking at the tire capacity rating, which would read "tire max load XXXX lbs/XXXX kg at YY psi/YY kPa. While this does indicate the maximum load a tire can safely handle, it is not an indicator of the tire construction, or whether it is designed to hadle tha max load for an extended period of time. That's where the ply ratings come in, which are the same for any country. While it is possible to have a P rated tire to have the same max load as an LT of the same size, the P tire will not last long under those max load conditions. Most P tires are rated at 4 ply, though some are 5. LT tires start at 6 ply (C range) and can go up to 12. Your truck would have had an 8 ply tire OEM. I've personally seen what happens when an underrated tire is used on a vehicle that cals for a higher load rated tire, even though the max load was the same. The lighter ply rating tire either wears out early, or in most cases, simply fails.

Hm ok. But how can I be sure to get the correct tire for my truck? When I look for tires all they state is a load index in addition to the speed index. For example 112S is a 1180kg/tire (112) at 180kph (S) safe vmax. Means you can handle a 2360kg axle load with both tires.

If the tire is LT rated, it will have a marking on the sidewall with the load range. LT tires will also have the load index and speed rating in the tire size.
Here's some information from Michelin on reading sidewall markings.

Well, I now understand. That wasn't explained on any site I found selling tires. I looked it up at Cooper Tires for my existing set (ATR). There they have a list which discloses the "LT" range of available sizes. Very interesting...

But what is the rim width I have? 7"? Do you know that? There is a lot of tires (in old sizes) and wheels listed in the manual, but I don't really know which rims I have. I don't think these are factory provided as there are nowhere 17" rims stated for the 1965 C-series. Only 17.5" as far as I can see. The mounted tires are definitely 255/70R17. I would measure it if the truck wasn't in the shop right now.

Many thanks for your patience and your very good help!

Edit: Bill, what size are the rims/tires on your truck? I've seen your photos and it looks great!

Joern, mine are 15x8 Chevrolet Blazer Rallyes with a 30x9.50x15 C range Michelin LTX M/S tire.
Just judging from your pics, the wheels you have are either aftermarket or from a later truck. Only real way to tell would be measuring them, but eyeballing it, they look to be a 7 or 8 inch. Either will be fine with the tire sizes you're looking at.

I really have to thank you, I've learned a lot! Even the tire guys don't know really about the rating. Without the forum I would have bought the wrong tires, no doubt.

I will keep the rims and get a set of LT275 Cooper Discoverer ATR.