Are tire valve stem solid rubber, or are they reinforced somehow?

The one on my rear tire has some dryrot and cracks.  I think the last bike shop I went to didn't change it when the tires was put on.  Cheap shits.  I guess I should get it redone now instead of later.

I mean, what good is it having that new tire with thick sidewalls if this shitty valve stem can leave me stranded or crashed?

Valve stems should be replaced whenever you change a tire, it's cheap insurance against a leak.  There is a threaded metal sleeve that the valve core screws into but if the rubber on the stem deteriorates it will leak.  When a valve stem gets really bad it will have a noticeable leak when you push it side to side. 

-Jessie

The traditional rubber ones will eventually crack at the base and leak.  That is a flat you won't easily "fix" on the road.  I use bolt in all metal types like the ones at www.patchboy.com.  There are some cool anodized 90 degree alumium ones too.

prs

90* sounds good.  It's always a trick getting my pressure guage or compressor hose on it even with a swivel head.

Here is a place with a snazzy look'n Shrader valve selection:

http://www.motorcycleanchor.com/tire_valves/index.htm

prs

BUT NEVER use a conventional 90 degree  rubber based valve stem on a cycle unless the cycle has a brace for it.  Sooner or later they crack and fail due to centrifical forces.

prs