215/60 Pirelli CN36 on 7R without tube? Spacer?

[swisscheese]

I know there are many threads about tires and 7R rims, but couldn't find an answer on this one: Am planning to fit a 215/60-R15 Pirelli CN36 on deep 7R; Is it possible to mount these without inner tube? What spacer is required on a 73S (non-rolled) rear fender? Front would have a deep 6 with 185/70-R15 CN36. I understood the Avon is a much wider tire than the CN36 in the same width? (couldn't find anything on CN36 / 7R / spacer / tube combo). thanks in advance!

[Jim Breazeale]

I know there are many threads about tires and 7R rims, but couldn't find an answer on this one: Am planning to fit a 215/60-R15 Pirelli CN36 on deep 7R; Is it possible to mount these without inner tube? What spacer is required on a 73S (non-rolled) rear fender? Front would have a deep 6 with 185/70-R15 CN36. I understood the Avon is a much wider tire than the CN36 in the same width? (couldn't find anything on CN36 / 7R / spacer / tube combo). thanks in advance!

You, most certainly.don't need tubes. You will run a chance of burning the paint off your rear quarter panels about 3" above each rear wheel opening, though.

Regards

Jim

[Arne]

I call that I have seen recommendations for 7mm spacers for this application. I "think" that's correct.

[blue72s]

Deep sixes and 7R wheels were designed to run with tubes. It is recommended that the minimum tyre profile (for tubes) should be 70 series, not less.

For 215/60, the 73RS wheel would be more suitable.

If I had 7R rear wheels, I'd fancy 205/70 (yes 205) and as far as I know, XWX is the only brand that offers this size. The overall diameter will be slightly more but not by much (half an inch). Look at race cars - their rears are usually taller than fronts.

[Arne]

Not a fan of those big 205/70 on the back. Awfully tall.

FWIW, the first 215/60-15 CN36 were tube type. So today's recommendation not to use tubes in 60% profile tires is a recent development.

I worked in tires for almost 25 years, and I tend to agree that tubes are a good idea in deep sixes and 7Rs. But I'm definitely in the minority on that opinion. Many people run them tubeless with no issues.

[Jim Breazeale]

Deep sixes and 7R wheels were designed to run with tubes. It is recommended that the minimum tyre profile (for tubes) should be 70 series, not less.

For 215/60, the 73RS wheel would be more suitable.

If I had 7R rear wheels, I'd fancy 205/70 (yes 205) and as far as I know, XWX is the only brand that offers this size. The overall diameter will be slightly more but not by much (half an inch). Look at race cars - their rears are usually taller than fronts.

Millions upon millions of cars made before 1968 are running tubeless tires using wheels "designed to run with tubes".
When are we going to get rid of this old wife's tale?
We shouldn't go swimming for, at least, one hour after eating, too!

Regards

Jim

[Arne]

Sorry, Jim. I'm a big fan of bead retention humps on tubeless wheels. I've seen too much carnage from sudden deflation without the hump. But we all have our own risk tolerance level. To me, running a tube in a tire is a small effort for a bit of additional safety.

[swisscheese]

Deep sixes and 7R wheels were designed to run with tubes. It is recommended that the minimum tyre profile (for tubes) should be 70 series, not less.

For 215/60, the 73RS wheel would be more suitable.

If I had 7R rear wheels, I'd fancy 205/70 (yes 205) and as far as I know, XWX is the only brand that offers this size. The overall diameter will be slightly more but not by much (half an inch). Look at race cars - their rears are usually taller than fronts.

> thanks. 73RS 7J wouldn't fit under a standard-flared '73, hence the 7R wheel. I'd guess, if I run into trouble with a 215/60, I will most certainly get issues with 205/70's, wouldn't I?

[swisscheese]

Sorry, Jim. I'm a big fan of bead retention humps on tubeless wheels. I've seen too much carnage from sudden deflation without the hump. But we all have our own risk tolerance level. To me, running a tube in a tire is a small effort for a bit of additional safety.

What would be against running tubes on the deep 6 and 7R? In general nothing, but fitted with 185/70 and 215/60 respectively.?..

[RennTyp]

I think there's the additional issue of the valve holes with running deep 6 / 7R without tubes. These wheels won't seat a tubeless valve securely without modification. They can be modified but finding someone you can trust to do it isn't easy.