Have you had a valve stem failure?

Geezer · Oct 3, 2008

There have been a few posts where people mentions valve stem failure on the FJR. I'd like to know how many peopel have experienced this and what kind of stem it was that failed.

I would say that your valve stem failed if it cracked, split, or came loose from the wheel. A loose or bad core would not qualify as a stem failure for this poll.

Bluestreek · Oct 3, 2008

I have heard of 90 degree valve extensions failing at speed

Bike Effects · Oct 3, 2008

The valve stems that I sell are used by many including a couple of AMA superbike/supersport teams and have not suffered a high speed failure that I have ever heard of. The design of the stem is important. A "bent pipe" type of stem would be subject to high speed failure due to centrifugal force. Mine are machine from on piece of stock.

Angled valve stems at Bike Effects

Ignacio · Oct 3, 2008

Bluestreek said:
I have heard of 90 degree valve extensions failing at speed

Who? Where? When? What brand/type? Installation issues?

FJRay · Oct 3, 2008

I know at Bonneville they require valve caps that are oring sealed to prevent air loss at speed.

vectervp1 · Oct 3, 2008

Bluestreek said:
I have heard of 90 degree valve extensions failing at speed

I've heard of this happening too. It was in reference to 90 degree caps you screw on to your valve stem to make them stick out the side. Too much uneven weight and it rips the rubber on the valve stem. Never seen it happen, only heard of it.

Rogue · Oct 3, 2008

I saw a non-forum FJR that the rear OEM stem split at the 06' 1088.I had a spare 90* stem I lent him. Here is me helping him in the hotel parking lot.

Fred W · Oct 3, 2008

Nice use of the side stand bead breaker all our FJRs come equipped with, albeit a kool-aide drinker's in this case. Also good that the final drive didn't leak on the tire being de-beaded,

Always good to see you down on your knees for a fellow FJR rider in distress,. But next time think about breaking out those knee pads. Us gray haired guys need all the help we can muster... :lol:

Silent · Oct 3, 2008

Bike Effects said:
The valve stems that I sell are used by many including a couple of AMA superbike/supersport teams and have not suffered a high speed failure that I have ever heard of.

Gotta agree with Jeff, his stems are a nice bit of work! They have been working very well on my '07 right up into "go directly to jail" speeds B)

spalkin · Oct 3, 2008

vectervp1 said:
Bluestreek said:

I have heard of 90 degree valve extensions failing at speed

Click to expand...

I've heard of this happening too. It was in reference to 90 degree caps you screw on to your valve stem to make them stick out the side. Too much uneven weight and it rips the rubber on the valve stem. Never seen it happen, only heard of it.

I think the problem is more from checking and filling the tires rather than the slight flexing from centrifugal force.

Having a 90° valve stem would mean that you couldn't press too hard without supporting it from the other side or you could weaken it.

weekend rider · Oct 3, 2008

It is the rubber valce stem whether 90 degrees or the straight ones that fail. They elongate at high speeds.

Bike Effects 90 degree stems are machined and designed for the higher speeds. Have never seen one of his stems elongate and fail!!!!!!!!!!!! :fans: :drinks:

Happy Dog · Oct 3, 2008

I had a problem with a 90 degree valve stem but it was an installation error. Caused a slow leak. Fixed it and haven't had a problem since.

Fred W · Oct 4, 2008

weekend rider said:
It is the rubber valce stem whether 90 degrees or the straight ones that fail. They elongate at high speeds.
Bike Effects 90 degree stems are machined and designed for the higher speeds. Have never seen one of his stems elongate and fail!!!!!!!!!!!! :fans: :drinks:

If what you meant to say was they deform then I agree. But from a pure physics standpoint I fail to see how a valve stem mounted on the inner surface of the rim would elongate at high rotation speeds. If anything it would compress and deform. Clearly the valve core would have the possibility of being depressed under it's own weight due to the high centrifugal force of ultra fast rotation (like during speed records on the salt flats, etc.), but then I'd think that having the 90 degree stem orient the core at a right angle to the force would eliminate that possibility.

I would imagine that any 90 degree stem that is rubber and is merely press fit mounted to the rim would be a problem during use (filling / checking). The stem to rim seal might be suspect during high rpm use as the centrifugal weight of the entire stem would want to push out on the heavy side. The mechanically fastened ones from Bike Effects would seem like a safe bet in all regards. I'll probably put some on my next order, whenever that is...

NoCage · Oct 6, 2008

Bike Effects said:
The valve stems that I sell are used by many including a couple of AMA superbike/supersport teams and have not suffered a high speed failure that I have ever heard of. The design of the stem is important. A "bent pipe" type of stem would be subject to high speed failure due to centrifugal force. Mine are machine from on piece of stock.
Angled valve stems at Bike Effects

Yep... I have these and they've seen triple digits with nary a problem. :good:

Bounce · Oct 6, 2008

Ignacio said:
Bluestreek said:

I have heard of 90 degree valve extensions failing at speed

Click to expand...

Who? Where? When? What brand/type? Installation issues?

not yamaha, but wings came with rubber 90's and a clip to keep them from straightening out at higher speeds. lose the clip, lose air pressure. i'd consdier that a failure.

Geezer · Oct 6, 2008

The reason I started this poll was this thread.

I am thinking that maybe I'll replace the rubber Yamaha valve stems with some all metal ones. I'm not really into the 90 degree stems, but I've seen plenty of straight metal ones on other bikes.

luvtoride · Oct 6, 2008

I had a valve stem failure. Had one of those stupid skull caps on my bike that was given to me by a friend when bike was originally purchased. (not yet a seasoned FJR'er).

Left stranded about 50 miles from home. The skull cap got shitcanned.

I now run 90 degree valve stems that Bikeffects sells.

Edited to add: Greg, I know of the post that you are referencing. Nobody is sure the cause of Wayne & Annette's accident. The cause being a split valve stem allowing a rapid release of air in his front tire is speculation. I suppose that once Wayne is able to examine the bike, we'll know more about the front tire.

dcarver · Oct 6, 2008

Never a valve stem. 1 Schrader.

SkooterG · Oct 6, 2008

Geezer said:
I'm not really into the 90 degree stems

Why not?

I've got the Ariete 90 stems from Jeff on all 4 sets of my FJR wheels. Yep, that's right, all EIGHT of 'em!

Have you had a valve stem failure?

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