70T with steel wheels, do I need tubes as i broke down two wheels and the ancient Dunlop 185/70/15 had tubes in them, and were quite (very) heavy? 195/65/15 replacement tires going on.
70T with steel wheels, do I need tubes as i broke down two wheels and the ancient Dunlop 185/70/15 had tubes in them, and were quite (very) heavy? 195/65/15 replacement tires going on.
Last edited by AKAMick; 07-18-2019 at 09:37 PM.
Current fleet, mostly rubbish automobiles and other assorted junk.
So I had a spare in my car with the original steel wheel, a 71T. I swapped a better older tire to it during a tire change. It had a tube in there. No idea how old the tire was, no date markings. But it felt OLD. Tire shop (they deal mostly in older cars only) said I could run a tubeless on it fine, but, the wheel did not have the safety hump and in event of a blowout, that makes it slightly more likely to lose the tire off the rim.
That said, everyone here with earlier Deep6 wheels is in the same situation. And from what I understand, tubeless tires don't want tubes.
I'm sure there are others here with better knowledge of this.
if the wheel has two humps no tubes are needed.
Usual designations would be eg. H2 FHA-H FH2 etc.
Quite often you can make a quick check by looking at the rim size stamped on the rim. Example, if the rim is stamped "5 1/2 J 15", then the J refers to the safety humps and a tubeless tire can be used. If the J is not there, then a tube is recommended. The 1970 time frame is about when the change occurred. So earlier design rims such as Fuchs 4 1/2, 5 1/2 and early 6" along with the Mahle gasburner 5 1/2 were not J type.
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The Dunlops were the second set of tires fitted to the car, 37K miles, last reg, 1983, the spare still has the unused original Firestone Phoenix 165/15 tube tire on it, the rims have a J stamp,
Last edited by AKAMick; 07-19-2019 at 11:24 AM.
Current fleet, mostly rubbish automobiles and other assorted junk.
As I recall from my years in tires back in the '70s, the tubeless wheels (J profile with humps) came out prior to Porsche's shift to tubeless tires. It was not unusual to see tubes used on tubeless wheels from the factory in the early '70s.
As for now, as others have noted, if the wheels lack the safety humps, tubes are recommended. However, tubes for low profile tires are not readily available these days. I'm not sure if the tubes you would use with 185/70-15 (often made by Michelin) are OK with the 65-series tires. If tubes that are approved for 195/65-15 are not readily available, I'd go tubeless. While there can be issues with bead retention while under-inflated with tubeless on tube-type wheels, stretching a tube into a size/profile it is not designed for can cause sudden tube failure.
- Arne
Current - 2018 718 Cayman, Rhodium Silver, PDK
Sold - 1972 911T coupe, Silver Metallic; 1984 911 Carrera coupe, Chiffon white; 1973 914 2.0, Saturn Yellow; 1984 944, Silver Metallic
Not about steel wheels specifically but some info here might be useful since I shared some information from tyre manufacturer literature published contemporary with cars
http://www.early911sregistry.org/for...ghlight=Tubele
You can run a tubeless tire on any rim that will hold air. It may not be "recommended" by the manufacturers but that is their product liability lawyers (who probably have tubeless tires on their personal vintage cars) speaking. by the way, all 15 X 5 1/2 steel wheels that came on 68 and later 911s and 912s have the "safety" bead.
Regards
Jim
In the event of an incident involving a car running with tubeless tyres on a wheel without the humps could/would that be grounds to invalidate third party liability insurance cover ?
A former colleague mentor once coached me on a decision I was facing that involved risk/liability. The wise old owl wouldn't tell me his view but asked cryptically "does it pass the beach house test"? Mystified I asked what he meant. He said " if you have a beach house before this decision for which you are liable and it went wrong would you still have it? Always stayed with me.
S
Last edited by 911MRP; 07-19-2019 at 10:05 AM.