Inner Tube Stem -- Offset or Center -- Rubber or metal

[timberstone]

Installed new 19 inch inner tubes in the rebuilt wheels that were done during the frame up restoration.
Some inner tubes had valve stems that were center metal -- just like the motorcycles.
Thought that the look of metal valve stems was an improvement over rubber valve stems.

Have some inner tubes installed with offset rubber stems but they do not have the "improved" look of metal stems.

Last weekend, while driving home from the Williamsburg British Auto Show, one of the inner tubes with a center metal stem blew out. Could have been dangerous if there had been oncoming traffic.

See photo of the stem segment from the tube:

Does anyone have experience with such a blow out?
Can anyone tell whether the tube was defective, or is it just not a good idea to use inner tubes with center stem valves?

Where can 19 inch inner tubes be found with offset metal stems for the 19 inch wheels?

[Steve Simmons]

The correct stem is a TR-13 offset. I've heard of people running center valve stems without issue, but personally I wouldn't do it because there's a lot of stress on that stem. The tube will be trying to pull it center the whole time it's in there. If I had to run center stems, I would make sure I had those plastic grommets in the valve holes to prevent the metal edge of the hole from cutting into the stem.

[timberstone]

Any thoughts about this tube? (-- listed by Coker -- )

This is a 500/600R19 tube with a TR11 Offset Metal stem. Recommended application is for Radial tires and the recommended tire fitment is for a 500/600R19 tire. Fits 500-600 width, 19 inch diameter tires. This tire inner tube has a TR11 Metal stem Valve stem and the location is offset. TR11 stem is threaded metal stem 1 1/2 inch tall with 5/16 inch diameter.
SKU: 86430

Quite expensive and a bit large -- can it be used for Bias ply tyres?

[Steve Simmons]

That sounds like a pretty big tube to put in a 4.50 tire. Better to go with a tube that's a bit too small and let it stretch than to risk having folds or creases. Also the risk of pinching the tube during Tire installation.

[Russ Wilson]

I had a failure like that last summer on tube with an offset rubber stem. It wasn't a blowout, but a fast leak from a crack at the same location. I replaced it with a 450/500 x 19 Blockley with an offset metal stem from Abingdon Spares (#69-007). This tube was noticeably heavier than the failed tube, so it obviously has a thicker wall. The joint between the tube and the stem looked more robust, and the stem also had a nice centering locknut to keep it in place.