New tires - recommendations

Mark_Toro

Mark_Toro

True Classic
Well, I now have nice shiny wheels and center caps. Friday is payday and it will be time to get Dominick its own set of tires - that hold air!

I'm using the original '74 steel wheels. Yeah - there are a lot of more exciting options, but I have these and it would be good for me to understand how the car feels before modifying.

The Cinturatos from Longstone or Lucas Tire are beautiful and would be the correct 145H13 size, but at over $100 per tire are a bit too expensive. Remember the initial buy in was $200 and I don't yet have a title or know if the engine turns over. Just removing the old tires and disposing of them added 50% to my investment. 😂

I'm thinking of keeping them narrow (165 or 175) and a higher aspect ration (70). Seems like there are several Chinese options in the ~$50 range in these sizes. Of course I don't recognize any of the brand names.

Anyone have a good recent recommendation?

I know these wheels were originally set up for tubes, but the PO was running tubeless (based on the valve stems). Thoughts on this? Should I go back to tubes?

Thanks
Mark
 
Although people have used 74 rims for tubeless tires, their design is not considered safe for them.
 
Maybe that is why there was so much curb damage on these wheels. :)

I've done a Midget with tubes (and wire wheels) so no fear going that direction.
 
When your car was designed, certain performance objectives, such as responsiveness, ride comfort, controllability, rolling resistance, and grip are set as targets.
The wheel/tire combination helps the manufacturer meet those objectives. Early in the suspension engineering process for a given car, the overall diameter (OD) of the tire is determined. In the late 1960's and 1970's tire designers developed successful wider and lower profile tires. When vehicle manufacturers utilized these wider low profile tires, they used tires with the same OD as what the car originally was designed for. When using a wider tire, the vehicle manufacturers selected wider wheels to support the wider tire cross section to optimize the benefits of the new technology. As for the X 1/9, here is how Fiat/Bertone approached the technology:

Year Tire size Details Tire OD Wheel width Details
1974 145HR13 tube type(TT) 22.29 4 1/2 wheels have no safety humps
1975 - 1978 145SR13 some TT, 22.29 4 1/2 some X had tubeless(TL) wheels and TL tires
1979 - 1981 165/70SR13 TL 22.29 5 wider wheel, all are TL
1981 - on 165/70SR13 TL 21.37 5 or 5.5 optional is 185/60HR13
1983 - on 185/60HR13 TL 21.37 5 or 5.5

I worked for an Italian tire manufacturer as a factory liasion with our dealers and consumers in the 1980s.
BY TIRE INDUSTRY STANDARDS, it is not correct to put a tubeless TL tire
on a TT wheel. Under certain circumstances like high side forces, it is possible for the TL tire bead to walk across into the drop center of the wheel. When this happens, there is something called an explosive decompression. The tire instantly loses all its air and the rim digs into the pavement. There are problems when you put a tube in a TL tire that have to do with incompatible textures and also, heat build up. At times, it was difficult to pursuade tire retailers to actually follow industry standards or to do the right thing. At the retail level, it is easier to sell the tire you have in stock and not to take the chance you will lose the sale when you have to special order the correct tire or wheel.

You have not specified your intended final use(s). Is it a daily commuter? Do you sometime exercise the chassis and approach the grip limits of the car? If the use is simply cruising, any tire which is the correct size and holds air will do (and most tire retailers will tell you that).
I push my street cars, so I am inclined to follow Tire Industry Standards.
So, faced with your fitment, I would have searched and found a set of 4 1/2" TL Fiat wheels and restored them and 145R13 tires from Coker Tire.

Finding the correct size 145R13" (also designated as 145/80R13) tires is an expensive and difficult process. It is hard to find 80 series these days. Same for 13" 70 series tires like 165/70SR13 and 175/70TR13. 4 years ago, I found four 175/70TR13 Michelin Defender tires at Discount Tire. I mounted them on Fiat Speedline Iron Cross 5 1/2 x 13 alloy wheels. Today, on 5 1/2" wheels, I would look at 175/70TR13 Hankook Kinergy tires at Tire Rack for $80 each.
In conclusion, just follow Fiat's lead. If you have 4 1/2" wide wheels, stick with 145 or 155 wide tires. If you want to make life easy on yourself, you should follow Fiat's move to wider wheels(with the correct backspace) with the right size wider tires. Any wheel wider than 5 1/2" or tires wider than 175 or 185 may rub stock fenders or fender liners. What works is shown in the chart above.
 
Try PriorityTire. I am almost 100% sure Walmart frontends this site for their own as well. There are 10+ choices in the 165/70 range, and just shy of 50 choices in the 175/70 size. There are some 145/80 options, but nothing too great. I have ordered from them before and had no issues.
 
Eric - thanks for the direction to Priority tire. I'll check them out. Any brands you have used and liked (or used and hated?)

Thanks John - I've seen "explosive decompression" happen on TL tires on TL wheels. We'd call it "knocking it off the bead" when I rally crossed. No harm no foul at low speeds in the dirt. Clean up the rim, a shot of ether and you were back in business. I can imagine it could be messy at speed, but a lot of things are.

First goal for the tires is to hold air and allow me to move it around the barn w/o nursing it with a compressor. :) But when I get it running, it will be a back road cruiser. I'm envisioning this car like the Midget - not fast, just fun. If all works well, it will go to Wisconsin in 2025 (700 mile round trip). Not on the highway. If I want to barnstorm, the supercharged GTV6 will do that job.

Consider a wheel change - I figure $250 for a set of wheels, if I am lucky, and then shipping at $100 plus. Plus the time and $ to refinish them. Let's say best potential is $450 all in. Nope - not going to go there. I already have too many sets of Alfa wheels hanging around. 🤣 (Do Alfa and Fiat wheels cross bread? I hope not.)

Given the path above, then the Longstone Cinturatos sound better ($550 for five tires and tubes - plus shipping - let's say $750 all in). Maybe this is the best, correct path.

If nothing else, I will strongly consider running tubes. My suspicion is that the incompatibility of TL tires innards will cause slow leak down rather than blow out.
 
Well, John had me concerned with the whole matching tire to tube thing, so I visited our friends over in the MG world. They have similar light cars and wire wheels, so they know the tube challenges.

Basically my take away from several threads (including some pretty good rants) was:
Installing tubes in "tubeless tires" creates a serviceable assembly given a few limitations:
  • Remove any stickers and obvious areas of potential chaffing on the inside of the tires
  • Use ample talc
  • Use a quality tube
  • Don't use tube in low profile (less than 65 aspect ratio) tires. There was controversy here, as some had run this way with success.
In the end, the flats from tubed tires were either punctures or slow leaks. Not blow out under load.

There was also some good conversation of running tubeless tires on rims without the safety hump with no tube. I couldn't see a clear verdict there.

Since I'm planning 70 aspect ratio or greater and my wheels don't have the safety hump, I think I'll run tubes as Fiat intended. But I won't feel bad about running cheap tires with the tubes.

But those Cinturatos sure are pretty. :)
 
Mark_Toro said:
Well, John had me concerned with the whole matching tire to tube thing, so I visited our friends over in the MG world. They have similar light cars and wire wheels, so they know the tube challenges.

Basically my take away from several threads (including some pretty good rants) was:
Installing tubes in "tubeless tires" creates a serviceable assembly given a few limitations:
  • Remove any stickers and obvious areas of potential chaffing on the inside of the tires
  • Use ample talc
  • Use a quality tube
  • Don't use tube in low profile (less than 65 aspect ratio) tires. There was controversy here, as some had run this way with success.
In the end, the flats from tubed tires were either punctures or slow leaks. Not blow out under load.

There was also some good conversation of running tubeless tires on rims without the safety hump with no tube. I couldn't see a clear verdict there.

Since I'm planning 70 aspect ratio or greater and my wheels don't have the safety hump, I think I'll run tubes as Fiat intended. But I won't feel bad about running cheap tires with the tubes.

But those Cinturatos sure are pretty. :)
Click to expand...

A false economy in my mind. Perhaps it’s a function of how I drive and autocross.

Check out that left front tire
IMG_1711.jpeg


There is a much better image from a 1973 road test which shows an XAS tired X where the tread is at least an inch inside the side of the rim. Perhaps someone with better Googlefoo can find it.

You might check https://www.tires-easy.com/
 
Karl - I agree - the tread moves around quite a bit, especially as the aspect ratio increases. I autocrossed my '66 Bonneville once and the tires rolled all the way over to the white walls! Hubcaps flew off (wheel flex) and I nearly ran one over as it was zipping across the parking lot. Needless to say I was young and this was not an SCCA event.

I'm narrowing my search. Thanks for all the help and advice.
  • Tire size - 175-70R13 (to get a slight increase in rolling radius (22.6 OD versus 22.1OD on the 145H13) = lower revs at speed).
  • Tube - Michelin 13E13 (Longstone for ~$15ea)
There are plenty of tire options in the $50 range. Crazy names. "Waterfall Eco Dynamic", "Iris Ecoris" etc. I'm kinda drawn to the Petlas Elegant PT311. :)

Anyone have experience at this end of the pool?
 
I went with these. My X is a casual driver & only sometimes push it. They've been solid for the few years I've had them. Drove plenty in the rain at the FFO last year without issue. I can't bring myself to buy more expensive tires. This is my 3rd set of tires (different brands) since 1998 & the last 2 dry rotted before they wore out.

 
For slaves, yeah whatever. But on the road - I will never use a cheap tyre. Exactly like a cheap helmet or a cheap parachute... Yeah, tyres go off/degrade long before I can wear them out but tyres are a consumable and when they get nasty, replace them.
 
Steve Thomas said:
For slaves, yeah whatever. But on the road - I will never use a cheap tyre. Exactly like a cheap helmet or a cheap parachute... Yeah, tyres go off/degrade long before I can wear them out but tyres are a consumable and when they get nasty, replace them.
Click to expand...
Lets not confuse "cheap" with a good "value".
I bought a set on Michelin Defenders for my minivan when they were the "top of the line" for them. Supposed to be a 70000 mile tire. They were quiet, but were at the wear bars in 40000, all evenly worn. Went back to the dealer & because I didn't have documented alignments every 6 months they wouldn't do anything.
My local tire guy once told me (30+ years ago): Michelin make a great tire. But if you have a problem, its not their fault because they make a great tire...
I agree the cheapest tire is not always going to be great. The last ones I had were Nexen. Didn't like them. Were loud & didn't last. I had Nexens on another car (different model tire) & they were good. Tires in this size are hard to come by. These have surprisingly good reviews & I've been impressed. There are quite a few members running these & are happy as well. Price ended up being a huge plus. A great value to me. Just my
1707265761318.png
 
JKIDD said:
Lets not confuse "cheap" with a good "value".
Click to expand...
Absolutely. One of things I hate more than cheap garbage is brands who think I will pay just for the brand.

But the issue I see is the ton of new rubbish brands coming out of asia. They are cheap - that is their entire feature list.

My preference is my direct experience augmented by the experiences of others. And its a moving feast anyway :)
 
Steve - you hit on the big challenge. It is a moving feast. And for a newbie like me, it is a wide open field.

I'm glad to build off the experience of others - like you, I weigh that with my own experiences too. Hopefully this brings me as close as possible to a good decision (like using tubes with these wheels)

Since JKIDD shared his actual experience with the Achilles, I value that. The experiences we share build the community.
 
When the discussion turns to safety and driving a car like the X1/9, it all seems rather contradictory. If safety is a primary concern drive a modern car with a multitude of air bags, side impact structures, etc. To be really safe just stay off the roads altogether.

Having said all that, I always buy decent tires.
 
When the discussion turns to safety and driving a car like the X1/9, it all seems rather contradictory. If safety is a primary concern drive a modern car with a multitude of air bags, side impact structures, etc. To be really safe just stay off the roads altogether.
Click to expand...

Life is about risk management. I guess that is one way to deal with it. 😂
 
It's a 2 seated, mid-engined, Italian sports car..... Why put anything other than a performance tire on it? It's like going to a fancy engagement in a Tux and flip flops ....... Ridiculous...
cee8b3af7bcbab0470223052d22c7d94.jpg

0d89677ee9a6505d483c53535fff6fb8.jpeg
 
😂 🤣 Awesome!

Dominick is a $200 pile of junk that doesn't run. Low cost tires will hold to the theme. :) (Hey consistency is important!)

I'll post pictures in a couple of weeks as this all comes together. Someday If the project is a success, there are so many cool alloy wheels - that is the time for better tires.

You know, If I wore a suit that um...... unique. I'd probably wear flipflops to distract your attention. 😂
 
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