Front wheel valve stem cap hitting fork

I have fitted the tube supplied in the kit to the front wheel. After installation of the wheel into the front fork I found that the tire would not rotate without the valve stem cap hitting the front fork. Van's replied the solution is to remove the cap. I'm not happy with this solution. Goodyear aviation tire manual states, "Make certain that every valve has a cap to retain inflation and prevent dirt, oil, and moisture from damaging the core."
Does anyone know of a tube that has a shorter valve stem that would allow the tire to be fitted with its cap and thus remain airworthy?

I have the same issue and feel the same. Hoping I can
find an ultra low-profile cap or something to replace the
big yellow nut. I know my RV-10 has the same tire
on it, and while they do have clearance issues too, mine wasn't nearly as severe as with this tube. I'm not sure off hand which tube or stem design I use on that one, but certainly that will be getting replaced soon down the line because I'm not going without a cap long-term. There is a lot of rubber
dust and crud that builds up in there.

PS: I also replaced my axle. I'm surprised that they are still sticking with that same design. It's far from optimal. The wheel is a matco wheel, and Matco also makes a much better axle for the front wheel. Check it out, it's not that expensive.

WHLAXLE24 Axle Assembly, A24 1.25 Inch
WHLA24SPKIT

Those are the 2 part numbers you need.

We fitted a 500 x 5 nose wheel to our 9A and had the same problem. We did find a tyre with a short stem (made for gliders) but it was very expensive.

In the end we drilled a hole for the valve stem to exit through the opposite wheel half - so the valve tube exits the hub on the opposite side - because the valve hole is offset in the rim the amount of valve stem exposed becomes much shorter. Works a treat!

Description (and rather crappy diagrams) here

Tim, if you have the Matco axle the wheel is closer to the fork on one side than the other. Check yours out, you can probably flip the wheel and have plenty of room. You can reverse the axle too, but if you already drilled you'd have an extra hole.

aerhed said:

Tim, if you have the Matco axle the wheel is closer to the fork on one side than the other. Check yours out, you can probably flip the wheel and have plenty of room. You can reverse the axle too, but if you already drilled you'd have an extra hole.

Click to expand...

I was wandering why I had clearance on the RV-10 but not on the RV-14. I'm having trouble with the nose fork and have not done any drilling. I'll have to check your method and see if I can get enough clearance with the cap on like I had with the 10.
Thanks

Link...

Tim Olson, -10 builder, has a website, the link is on the mothership page. On it is a list of 'must fixes' for the -10. I'm not there yet (or even close) but one of the items he mentions is the valve stem clearance. Might be worth taking a look. Good luck!

2015 dues GLADLY paid!

Aerhed, thanks for the reminder about flipping the axle. I will do that. I drilled the anti-rotation hole on the wrong side so just did the install witht he stem opposite too. I'll just drill the other side the same and flip the axle. That should take care of it. I think you're right, I do remember that it was different per-side, and on the RV-10 that does fix the issue.
One more reason to consider that axle...since it may give the opportunity to fix the stem nut clearance.

Measured mine last evening. The cap sticks out about a 1/16" now and by rotating the axle you gain just over a 1/16". It may clear but that's all on mine. Sure worth a try. Thanks for the tip.

Ron, which wheel do you have? I got rid of the rubber seals on this last one, so I may have a hair more clearance.

I have the 5.00 X5 that Van's sent with the kit and the Matco axle. I'm still using the yellow cap that came with the supplied tube.

Use a different cap

Use a plastic cap from your car or bicycle.

I flipped my axle around on the tire tonight and didn't find I gained quite enough clearance for the yellow cap yet, so I guess it's on to an alternative cap for me.

Ok, so in 10 years I've forgotten so much about building my RV-10 that I'm overlooking some critical information...

This whole valve stem issue is CAUSED by Van's not sending us the proper wheel for our application.

The wheel we get (for the RV-14A model) is the Matco NW501.25. That is the wrong wheel for use with the tube that is common that we get.

Desser did start making a tube with a short stem that we can use as an alternative, but, if you need one in the field (I have needed a tube in the field before, a year ago), you will be unable to find the proper tube locally. So that is one potential fix.

The better fix is to do this: DO NOT ORDER THE NOSEWEEL WITH YOUR KIT.
Instead, order the wheel direct from Matco and order the wheel number NW511.25, which has the cutout for the stem on the other half. The standard tube will then be useable with the wheel and you should not have valve stem clearance issues.

So I was burned by this twice, and I'm upset with my ignorance in not catching the issue before I mounted the tire. Once you mount it, you're stuck because your wheel is no longer new. If you have your finishing kit, stop now, and do a wheel exchange with Matco so you get the right one.

If you, like me, made this mistake, Matco will be able to help you out. Right now I'm in process of RMA'ing my wheel to them, where they will sell me a new 1/2 of a wheel, and machine my wheel with the cutout in the right area so our stem clears. This will be between $65 and $100 with shipping to get corrected, but you will be happier with it long term.

I'll write again once the wheel is back, and include a pic with the clearance if I can remember.

Tim
Great information, thank you for sharing. This is not your fault; this is an issue that Van's should look after for it's customers, free of charge. I would not accept this type of error from any other supplier. Using a non standard tube is not the correct solution if a proper wheel is available.
The finish kit is very expensive and for that we should expect the correct parts.

valve stem

I found a old metal valve stem cap with the extension on it to extract valve stems. Cut off the extended end and wound up with 1/8 inch clearance. I think that should work. What do you think?

Thank you everyone for your advice. I tried turning the wheel around for some extra clearance - no luck it still hits. I have used an automotive plastic valve cap and it spins freely now. However my local aircraft engineer pointed out that automotive caps do not comply with airworthiness standards as they could be blown off with pressure. The yellow metal valve cap is a mechanical seal and will stop air escaping. Still not totally happy, for such a beautiful design and build seems a shame to be let down by such a tiny issue.

I did take my Matco axle off today, drill the anti-rotation bolt hole on the other side, and mount my old Matco NW501.25 (the wrong one) wheel from my RV-10 that I still had around, with my 10 year old RV-10 tube and tire. That one always had a tiny bit better clearance (I think the tube stem was a very little bit shorter) than what the tubes do now. That one does have maybe just under 1/8" clearance when mounted now, if I mount the tire with the stem on the side with slightly more clearance.
I wouldn't call this the total solution, because the reason I mounted my old tire is because I have to ship my new one to Matco for them to sell me a new 1/2 wheel assembly and machine mine so in the end I have the proper NW511.25. But it is nice to see it fit with the yellow cap installed.

I also noticed already, even after just having it mounted for a few days, that the stem had been rubbing on the rim hole just a bit. That tube is really meant to have the stem further back (i.e. penetrate on the OTHER half of the wheel and still come out the same side), and having it mounted on the rim we got you could tell the metal stem wanted not to be in that location. So I will be very happy to have the proper wheel back once they finish.

Anyway, for any builders out there, I'd suggest not buying the wheel or axle with your finishing kit. Just get the axle and wheel from Matco together at the same time, when you order your finishing kit.
The parts you will cancel off your order are the wheel (you can still get the tire and tube from Van's), and also cancel the 2 U-1023, and 1 U-1009 part off your order. Mine are still unused, and I'll be sending it back to them. Heck, I still have mine from the RV-10 after giving up on that assembly there.

On a positive note, I fit my rear window yesterday, and I must say, whoever is producing the plexi for Van's did an excellent job...along with Van's and their sizing of the window. It takes a minute to read through and understand the process you're going to do, but the actual fit and finish of the window is excellent, and fitting it really would take almost no time at all if you know what the goal is. So where some parts like the wheel are frustrations, there are some periods of brilliance, too.

The solution is obvious: put the 3rd wheel at the back, where it's supposed to be!

I got my wheel back from Matco today and mounted the tire on it. I haven't put it on the plane yet, but here are some preliminary pics and a report on the valve cap clearance.

As you can see from the first 2 photos, the hole is in the other half of the wheel, which is the way it should be for our installation. Matco sold me a new 1/2 wheel and machined my other 1/2 with the hole, then pulled my bearing races out of the old wheel I sent them and put them in my new wheel half.

In the 2nd 2 photos, you can see a big difference in cap clearance will be the end result. When viewed from the forward side of the tire, you cannot see the yellow valve cap. I had to turn my viewing angle to the side of the tire to even see the cap sticking up. Then I laid a 2x4 on top of the tire, above the stem. The stem still has about 1/8" clearance from the board that is set at the width of the tire sidewalls. Now when you see your tire mounted on the forks, clearly the tire itself has plenty of room so it doesn't hit the fork. So the yellow cap will now be about 1/8" further away from the fork side than the existing sidewall of the tire is.
Much better, and now you can keep your metal hex cap installed.
Hopefully you all can learn from my mistake and save the added money I spent by allowing myself to be sold the wrong wheel in the first place.

Tim , I drilled my wheel hub as I explained to you and enlarged the mouse hole as per Matco for the washer and nut supplied with the tube. Van's tells you remove the nut and washer but they also state if there is a difference in instructions to follow the manufacturers instructions so I wanted to install the tube with the nut and washer. I took most of the evening to get the nut seated properly on the mouse hole. I'm wandering if this was because I modified my wheel or if you had the same problem when you mounted your tire?
Thanks Ron

Tim,
If I were to match drill the valve stem hole in the other wheel half, and fill the original valve stem hole, I would end up with a NW511.25 (valve stem clearance wise)?

In reply to Ron, so far I haven't used the washer. I just did it per plans. But, you have a good point regarding keeping the washer. I may have to look at that again. But I don't have one on my RV-10 and it's worked for almost 10 years now, so I am not sure I'll add it.

In reply to Barney, I guess I'll let Ron answer that question. Me personally, I prefer to do things right with no corners cut. Saving money is always nice, but when it comes to making a part 100% the way it should be, I usually pull out the wallet. If it were on my car, sure, I'd drill it. But without me knowing the exact dimensions of all the parts and such, I don't feel qualified to answer your question. I sent mine to Matco, and I think I paid maybe under $15 to ship it to them, and they shipped it back done with a bill in the $80's including shipping. So for under $100 I had it right. A whole new wheel is only $145 from them, so heck, if shipping it back to them isn't convenient, that would work too. I figure these are your tires that you'll be landing on at high speeds...not really worth compromising on quality.

That said, I'm sure there are other ways to skin the cat.

I agree with Tim on quality of parts I feel I never compromise for the cost of parts. With that said this is why I contacted Matco with my idea. They replied that I could indeed drill a second hole opposite the original but that I would also have to mill out the mouse hole a little larger to .550" wide and .671" deep, from rim edge to max. radius dept, to allow for the washer and nut supplied with the tube.
I have yet come up with a plan on plugging the unused hole and if there is a need to do so (probably there is). The valve stem has no seal around it either so water and dirt can enter but at a slower rate.
My personal feeling on this issue is that I'm not compromising anything as to quality.

Has anyone tried the Beringer RV10 nose wheel? Short vavle stem should solve the interference issue, tubeless design improved bearings and axle etc.

Tim, I'm wandering if the mouse hole you now have installed is also larger being your wheel was modified at Matco? I was told to enlarge mine for the nut and assume they would have enlarged yours. If so you now have a different set up than you did in your RV-10.

Ron
Thanks for the conformation and mouse hole dimensions from Matco. I match drilled another valve stem hole, increased the size of the mouse hole and filled the unused hole with proseal. After I bolted the two halves together, a little bit of play between the mouse hole and stem nut indicated that both halves were seated completely Clearance problem solved. Now the assembly is going to Alan for his nose wheel bearing mod.

Mine's completed

Hi Ron,

To answer your question first, my mouse hole looks like it's probably the same size as the original other one.

Now I'll add some additional info:

I was contacted off-list about another concern that I also saw and had. With the RV-10, there were no lightening holes in the fork, so drilling that hole for the bolt that serves as an anti-rotation bolt, was tougher. I drilled mine in an area less likely to weaken anything. That causes one issue, however. If you look at the pics I'll attach to this post, later the nose wheel fairing goes over that hole that I drilled. I didn't want to also put the hole into the fairing bracket if I could avoid it.

Seeing as though the whole purpose of that bolt is to prevent rotation of the axle, there are 2 things you can do. I called matco and both are acceptable. #1, you can just not drill that hole. The beauty of the axle design is that you can properly torque the main axle bolt, and really, if you have that tightened down, the axle won't rotate anyway, it will rotate only the wheel, and not the bearings either. So that is what would be my choice, had I thought of it at the time.

#2, if yo notice my pictures, I took a bolt that would nearly bottom out, cut the head off, slotted it, and used it as a threaded stud that would stick out just enough to keep it from rotating on the axle. Since there are 2 spacers on the axle, and you can remove them, this stud was short enough that I could just pull the opposite spacer and still pull the wheel off. That studd still prevents rotation. To prevent it from coming out, I used loctite on the thread. Now my fairing bracket can fit right over top of the hole. That bolt will now never have to be removed. I would have just left it out, but I may as well use it since I drilled the hole.

Finally, check out the picture of my final valve cap clearance from the fork. This is with the Matco axle, and the proper 511.25 rim. It is plenty of clearance, and there is no way the stem will ever contact the fork. So the end result is good.

Tube stem hitting fork

I followed the plans and removed the lower washer and nut, and mounted the tube/tire. The stem and its cap hit the fork, requiring me to remove the stem cap. This open stem would allow debris to enter the valve stem, and ignore the function of the cap to give additional protection against air loss. By comparison, when I mounted the mains, I left the lower stem washer and nut on the stem, and the stems protruded less from the wheel. Because of this observation I pulled the nose wheel off, deflated the tire, split the rim, and put the lower washer and nut on?in addition to the outer nut and cover cap. When I mounted the nose tire with the 4 components on the valve stem, it cleared the fork by 3/16?. Problem solved. I suggest leaving the hardware on the tubes, as suggested by the manufacturer. aa