Coker tire question

[rotorwrench]

On a tube type application, the rubber stem is somewhat reinforced in rubber around the metal parts that it's vulcanized to. It is generally heavier than the small slug that is removed from the wheel to allow for it. We are only talking grams here when referring to differences so it's not by much. Tire carcasses and treads are a lot more uniform on modern tires but the reproductions are made in pretty much the same way they were back then with some exceptions. The plys generally always have an overlap somewhere so there can be a fair amount of gram weight difference at the overlap points depending on the carcass design. Some tires are marked for runnout too to but I don't think any of the reproductions are and the old rims aren't marked for that either.

The dot is for reference alignment to the stem location on all the tires I've worked with including aircraft tires. The dots are usually yellow but now days, it's up to the manufacturer.

[Kube]

Originally Posted by rotorwrench

On a tube type application, the rubber stem is somewhat reinforced in rubber around the metal parts that it's vulcanized to. It is generally heavier than the small slug that is removed from the wheel to allow for it. We are only talking grams here when referring to differences so it's not by much. Tire carcasses and treads are a lot more uniform on modern tires but the reproductions are made in pretty much the same way they were back then with some exceptions. The plys generally always have an overlap somewhere so there can be a fair amount of gram weight difference at the overlap points depending on the carcass design. Some tires are marked for runnout too to but I don't think any of the reproductions are and the old rims aren't marked for that either.

The dot is for reference alignment to the stem location on all the tires I've worked with including aircraft tires. The dots are usually yellow but now days, it's up to the manufacturer.

Rotor, I'll take your word for the dot placement. thanks.
as a side note of sorts, I have found modern tubes to be horrible enough that to balance a wheel / tube / tire assembly has been nearly impossible at times.
While I realize this hardly seems possible, rest assured it is.

[rotorwrench]

I know what you mean about tubes. There is some real crap being manufactured with respect to tire tubes. Also, some tires have structural problems from the get go and can never be balanced without shaving them but who is going to do that in this day and age. Especially with a new tire. They used to do that crap with recaps but the only recaps now days are generally for trucks due to the expense of those. They are in a whole different league.

All of this stuff is mostly of foreign manufacture now days and quality control appears to be non existent for some.

Just to add: A lot of tires that are dot marked are very close all the way around so the the mark may be moot on some of them. As long as it gets to a fairly good balance. Most of the rotors on helicopters are balanced to a velocity of 0.2 inches per second which is saying that it's not perfect but it's close enough. I've had some that I could just barely make 0.2 IPS due to shaft run out and other factors. Tires aren't much different but you can only adjust balance. There is no easy way to adjust for wobble or tip run out.

[CarlG]

With my Coker Radials, I mounted them with the dot next to the valve stem, used balancing beads inside the tubes. The style tire I have does not have the ridge.