The Stovebolt Site Forums The Shop Area General Truck Talk Tall tires ( 215/85R16 ) - are they a catch 22 (taller vechile at higher sp

I am not sure what forum this should go in as this does not neccessrily falls into drive train but has to do with suspension. So if wrong place, my apologizes.

I bought a 54 3100 in daily driver shape, it has 15" lower aspect ratio tires, about 25" tall
I bought a 1951 project truck, it was cheap rusty but had a goid bench seat and 7 original 6 bolt wheels, what I was looking for for the 1954.

I plan on putting 215/85r16, power steering, disk brakes, still use straight axle up front. I would like to run on interstate now and then but like back roads and would like to stay safe.

Now for the question

5" to 6" taller tires raise the center of gravity. These trucks are not sports cars, they are (as we know) designed pre 65mph speed limit. So what have people done for safety improvements when running at these higher speeds?


What about shocks?
Sway bar?
Lowered the truck?

Any other ideas for me to consider?

Trying to get some ideas for my budget

Thank you in advance

Ps: I have driven cab over semis, 64 ford van, and a few other front axle vechile, so I know the limitations.

I have that size radial truck tires on my 1954 3100 trucks. They have the 6.50x16" wheels - your wheels might be 6.00x16" wheels.

These tires result in a 3-4" larger rolling diameter on my tires (resulting-in higher speeds at lower RPMs).

The tires make a noticeable ride-improvement. You might/will have to play around with the PSI. Adjust for the best combination of straight-tracking and smooth/easy steering (after checking setting alignment).

I have put the stock panel-body front sway-bars on my pickup (the Suburban came standard with the sway bar). The difference/improvement is noticeable.

Standard shocks work for me.

Lowering one of these trucks is not in my experience/vocabulary. My bet is that lowering causes many more problems than simply making sure all your front end parts are good and correctly adjusted.

oops, I see you have decided on power steering and power brakes.

I have no experience with those changes.

I can comfortably/safely cruise for hours at 65 mph on an Interstate.

I'd suggest waiting to make the power steering modification until you see how the truck steers with a well-restored standard steering system. Particularly with a relatively narrow tread contact patch you might decide P/S is not necessary or desirable. The steering effort increases pretty dramatically as the tires get smaller and wider, and it looks like you're going the other way.

Adapting power steering to a straight axle setup can be time consuming and expensive, particularly if you plan to run the original stovebolt six engine. Electric-assist steering is probably the easiest and least expensive way to go if you decide you really need power assist.
Jerry

Thank you for advice and passing on your experience.

I will definitely take a wait and see in power steering it could save me money and headache, both good things!. I need to get more miles on it to see how it feels. I would like to keep the 54 as close to stock... I stopped riding my Harley because inattentive drivers ... I want to be able to stop in time if I am behind one and they do a panic stop because of what ever gizmo their playing with.

I have the 54 insured as an infrequent driving vechile but plan on driving it as much as allowed. The extra height does give some help in the defense driving department, but I fear not enough.

Again thanks for putting up with my questions

I have the slender tall tires (7.5 16s) on a 66 half ton. As hotrod suggests, steering is easy and smooth without ps.

Take that advice with a grain of salt- - - -I've met Hambone- - - -he's a big guy in good physical shape, and he could probably steer a Boeing 747 without power assist!

LOL!
Jerry

I have 235/85/16's on my '38. I found a sale at Pep boys a couple of months ago. I paid about $380 for the 4 tires.
The ride is much better than the 750/17 bias plys I was using.

I run LT215 85R 16's on my 49 3100's stock rims and the ride and steering are nice. Likes been said you've got to play around with the air pressure. The steering is very easy at 40psi but the ride is too hard. 35psi is the compromise I settled on.
No tubes and so far they've held air for approx. 2K miles.

I'm gonna chime in on the side of no power steering as well. I'm running monster truck tires with a stock '54 steering box, and it's effortless with the tire pressure topped up. I still won't run at freeway speeds, the gearing is all wrong and (do not try this at home, kids) an unladen tonner literally hops from one expansion joint to the next on top of the Alaskan Way Viaduct, bouncing off the tires without flexing the springs at 45 mph... I won't be doing that again.

My most important upgrade was dual-reservoir power brakes; a power assisted disc/drum kit is probably the biggest improvement for the money.

One thing that isn't mentioned often enough for safe highway driving is a good seat belt. I installed three point belts in my truck when I had the cab apart. I won't leave the driveway without seat belts, hitting the solid steering shaft is something I hope nobody has to do.

Joe

I have 215/85/16 tires on a stock 52 1/2 ton. The caps on the steering arm link were replaced recently. Also, the truck has new shocks and a new tie rod.

Last year about this time I did a poker run of about 200 km length at a speed of close to 65 mph. I can say that I felt a little unsafe at that speed - I think the steering drifted occasionally.

Other than that these tires are great! The tires seem OK at about 50 psi.

Try more toe in. Toe in is measured in inches in the Manual (1/8"). It is actually better described as a function of angle measured in degrees away from straight ahead.
What's the difference? You are using larger-than-stock diameter tires.
1/8" no longer represents the same angle in degrees away from straight ahead as it does for stock height tires.
Carl

Try a little less than 50 psi - it might help the "wandering".

Have you done all the steering gear/assembly adjustments described in the Shop Manual?

I have lap belts; where do you mount shoulder belts ... I will do a search and I am sure I will find the answer here!

Thanks all for input.

The biggest problem with tubeless modern tires on the old tube style rims........is the stock rims DO NOT have bead locks humps.

Example
https://www.landyzone.co.uk/attachments/rim-a-jpg.62050/

Hasn't been a problem for me, so far.

One set with inner tubes.

One set tubeless (I have not driven this truck - only rolled it on/off for towing).

No bead lock humps. I'm going say that without them, we probably shouldn't be doing any radical rock crawling nor drifting on our stock rims with tubeless radials...

Yup....it's called a safety bead.

And safety is for sissies........the problems occurs when the tire looses air and the tire rolls off the rim almost immediately.

Let's call each other names.

Thanks for the warning.

Has anyone here had any first-hand experience with this problem on A-D stock wheels and the size tire in question?

No problem on my 49 stock 16" rims with radials without tubes.
Course I don't rock crawl or run over 55 mph normally. I have hit 65 when passing a slower mover than me but that is rare.....

It's fast approaching the 5k tire rotation without incident.
(knock on wood)

"So what have people done for safety improvements when running at these higher speeds?

What about shocks?
Sway bar?
Lowered the truck?

Any other ideas for me to consider?"

Over 100,000 miles on two sets of 215 85R 16 Michelin's. Seat belts, Bilstein shocks, front stabilizer bar, steering damper shock, re-do the brakes and do diligent maintenance. I do drive the highway for 2k round trips but in general I live in a small town and behave myself when I drive.

In the process of changing over to Bendix brakes which are cheaper, easier to find, and with greater surface area should stop a bit better. While there I will have a king pin set ready to put in if needed. You can't just drive them, they need care.

I am pulling the 16' wheels off of a donor truck; I will be inspecting them as I clean them up, remove rust, ....

Now the question has become a bit rhetorical: do I continue down this path or do I find modern 16" 6 bolt wheels (w/ safety bead)?

Cost vs safety vs originality vs how am I gonna use it a 60+ yr old truck vs my risk aversion ......

Another one of those fun decisions , which is a reason why I bought it and will make it my truck

I Keep learning from here (thanks to all the current and historic posts) some times the research seems like a plumbing project: one question leads to opening up another area of questions .... simple question leads to rethinking the whole plan (at times)

If you've got the dough most definitely get new wheels.
Most swap to 15" 5 lug when they go new but that entails new drums and maybe upgrading to disc's up front. Disc's up front entails a new dual master cylinder which then leads to deciding between manual or power brakes. It's never ending LOL...
We won't get into an new upgraded IFS and power steering LOL.

As an FYI
I had an original wheel break at the lug holes soon after I got it running. I was test driving it on the original bias ply's. It was the spare wheel that must have been under that 49 for ages.
But the other wheels were solid and as I posted they do fine for back road driving with tubeless radials.

Stock wheels, no tubes.

" . . .
Cost vs safety vs originality vs how am I gonna use it a 60+ yr old truck vs my risk aversion ......

Another one of those fun decisions , which is a reason why I bought it and will make it my truck . . . "

Cosmo is my long-distance daily-driver idol. Listen to him the most.

My 1954 1/2 ton Chevrolet trucks have:
- original wheels (15" or 16") and truck radial tires
- tire psi adjusted to maximize/balance between straight tracking (no wandering) & easy steering
- original-equipment panel-body front sway bar
- completely serviced to original specs Bendix brakes
- all original spec/design front-end parts that are tight, properly adjusted, and regularly greased
- 3.55 R&P in rear-end with all new seals/bearings
- properly adjusted front-end alignment AND properly adjusted steering gear
- added seat belts (I'll have left/right shoulder-belt (see Deve's write-up) and center seat-belt in the next pickup).

Go to Charlottesville, VA for a highway and a back-road drive in Cosmo's truck, and then come down to NC for another safe/smooth/quiet ride in my Suburban (wherein passengers can talk with each other at normal volume from front-to-back seats (even at very high speeds).

FWIW, I put the Juliano's seatbelt kit in my '49. Their instructions were very easy to follow and the 3-point kit install was pretty easy. The belts are very unobtrusive and even complement the interior. I'm like Joe H -- I did not like the idea of the steering column going through my chest in an accident at 65 MPH.