Valve Stem Size.

[N-m]

Summary: I currently believe one needs a TR412 valve stem for the pregen Ninja. They are spec'ed as 0.880 inches in length and 0.453 inches in diameter at the seal area.

What is factory specified size? Don't bother telling me to search. I just spent about thirty minutes on that.

Someone said 11.3 mm, and someone said 0.453 inch. These two do not match since 0.453 inch converts to ~11.51 mm.

I do not have a service manual but someone else said the info is not to be found there. Thanks.

[dcj13]

Originally Posted by N-m

What is factory specified size?

Someone said 11.3 mm, and someone said 0.453 inch. These two do not match since 0.453 inch converts to ~11.51 mm.

Are there different diameter rubber pull-through valve stems? I thought rubber pull-through valve stems varied only in length: the really short ones for motorcycles; varying longer ones for automotive tires.

The difference between 11.51 and 11.3 millimeters is 0.008 inch (about the thickness of 2 human hairs). For a tight interference rubber-to-metal fit, the difference should be insignificant. I buy the ones that motorcycle shops (on line and brick-and-mortar) sell, lube them up, and pull them into position, not worrying about minor hole diameter differences.

It's entirely possible that valve stem technology has shifted and I have been left behind: a couple of friends are coming over later this morning to mount and dismount motorcycle tires and Greg always brings new valve stems with him. I'll ask those guys if there's a new, different diameter valve stem out there.

(Editor's note: the author leaves his own valve stems in place at tire changing time if they didn't leak before and appear to be in good condition).

[N-m]

There have been different diameters for as long as I can remember. This picture shows two different sizes, both 1 1/4 inches in length. The smaller of the two, averaging 0.5915 inches in diameter, is what you get in the packaging labeled "0.453 inches in diameter."

I will measure up my rims and current valve stems today. I believe the tires and stems are factory originals on the 2006 model. The tires are looking bad and I would hate to lose either on the interstate.

I bet the 0.453 size is the correct size, or close enough that it will not matter. I just wonder what the factory in Japan installs. Perhaps I can solve that mystery shortly.

My motivation for using the correct size would be my having lost a valve stem on a heavily loaded service truck and unloaded pick up before. It is not pretty, leading to a short delay at best. I don't even want to think about it but do when you only have two wheels. For me the time and safety factors are just not worth the extra 30 seconds and $1.49 it takes to select and replace the valve stem each time you replace a tire.

[dcj13]

Nice B&S calipers!

[Motofool]

The lower surface is what seals.

IMHO, due to the dynamic forces that the poor stems have to deal with (centrifugal, suspension, steering, air pressure) the length and shape (bent or straight) is more important than the diameter.

I buy the shortest stems (like the original) at the local lawn care shop, as I couldn't find them anywhere else locally.

See this:
http://www.nomartirechanger.com/prod...vestem-std.htm

Stems which rubber shows little cracks should be replaced.

[dcj13]

Originally Posted by Motofool

I buy the shortest stems (like the original) at the local lawn care shop, as I couldn't find them anywhere else locally.

See this:
http://www.nomartirechanger.com/prod...vestem-std.htm

I've bought stems from No-Mar in the past.

Thanks for pointing out that riding lawn mower places will have the short stems! I'll keep that in mind if I'm ever short of (short) stems and need some right away.

[N-m]

Originally Posted by dcj13

Nice B&S calipers!

Thanks. A cherished gift from my beloved father, a retired machinist. He has actually given me several, with these and the Mitutoyo brands being the favorite, probably b/c I use them more than others.

As an aside, you'll not find any digitals in my tool boxes. My father trained me on these and they work well enough. I do like the digitals but my nephew, a career machinist himself, has stated it seems to be easier to make the digitals read what you think they should read instead of an actual measurement.

Many in my family were/are machinists.

[N-m]

Originally Posted by Motofool

The lower surface is what seals.

Agreed.

IMHO, due to the dynamic forces that the poor stems have to deal with (centrifugal, suspension, steering, air pressure) the length and shape (bent or straight) is more important than the diameter.

I agree, but a too large diameter will create stresses and gaps. A too small diameter will have gaps that may never seal properly.

I buy the shortest stems (like the original) at the local lawn care shop, as I couldn't find them anywhere else locally.


See this:
http://www.nomartirechanger.com/prod...vestem-std.htm

AHA! That is what I am after. Assuming they have the correct diameters this is what I will go with long term. Thanks for the link.

Stems which rubber shows little cracks should be replaced.

I agree on the dry rot issue. Changing them with each tire should prevent this from being an issue unless you are riding the bike so infrequently tread wear is not the reason for replacement. This set of tires is actually being replaced due to age and dry rot, not tread wear. I can safely assume the stems have the same issue.

[Motofool]

Originally Posted by N-m

......I agree, but a too large diameter will create stresses and gaps. A too small diameter will have gaps that may never seal properly.......

There is interference as the hole in our rims is 10 mm.

Cleaning the internal rim surface, this pulling tool and some rubber lubricant are good things for preventing any microscopic damage to the rubber and little leaks:

[N-m]

This is what I use. It works well.

[N-m]

Here is what I found when I began digging:

Motofool recommended this valve stem, which I found to be a TR412. I am guessing the TR designation is an industry or manufacturing code for this size valve stem.
http://www.nomartirechanger.com/prod...vestem-std.htm

TR412 seems to fit well and is a nice, short length that does not get in the way of the rotor as much. I cannot verify this is the factory spec, however. I did find it to be the valve stem on my rims. I have said before I believe this is the original tire and stem set so I would think these were installed at the factory.

More info on the different sizes of stems can be found here:
http://www.tirerack.com/tires/tirete...jsp?techid=208

Interestingly the TR412 is the same diameter in the "seal area" as the next size up according to the chart found at tirerack.com. My measurements on the TR413's I bought do not bear this out. Apparently there is a large manufacturing spec for valve stems? Below are pictures of the TR412 I pulled from the rear tire and a new TR413. The TR412 is the shorter of the two.



The local O'Reillys sells the TR412 for $0.49 per unit and have ordered me some. Hopefully I pick them up tomorrow night. No other auto parts store, wally world or TSC had them listed on their website. Our lawn care stores are "Mom & Pops" that will not open through the weekends so I did not check with them.
http://www.oreillyauto.com/site/c/de...lves+%26+cores

I will be bringing in my rims as they are disassembled so I can get an accurate measurement of the stem holes. I hope this fulfills your every desire to know as much as possible about the valve stems found on a pregen Ninja.

[dcj13]

The shorter stem, the better for bikes.

The Helios caliper I got from my late father has a vernier scale (no fancy dial!). My day-to-day go-to caliper is the cheapie dial-gauge Harbor Freight Phase II, but I'll occasionally use the old-school one. Enjoy and treasure your dad's B&S caliper!

And the generic short motorcycle (or lawn tractor) valve stem will work just fine.

[N-m]

Thanks, D.

Notice - The above part number is for a box of 50 TR412 valve stems at O'Reilly's. If you want a two pack of valve stems then you need 17-412 for $2.99 at my store.

More to come. Going to bed.