Sting Sport Owners: Don't be a Free-Wheeler!

[drdehave]

Like most of you, I am sure, from time-to-time, the air "felt funny" whilst I was flying. Sometimes this came through as a definite vibration, which, for a long time I took to mean the different kinds of air I was flying through. But eventually, I could tell that the vibration was coming from the fore area and was not always air-related.

Know what it was? A free-wheeling nose wheel! I didn't confirm this until I started hanging video cameras at various places on the airplane--including off the metal step--and actually saw it spinning in the videos! At certain higher airspeeds, because the wheel was not perfectly balanced, it set off some pretty good vibrations felt throughout the plane.

And that's when I discovered "How To Replace The Nose Wheel Snubber" at the Sting + Sirius website (click on "Support," then "How To"). The fix (a piece of rubber fuel line placed inside the axle housing to dampen the spinning of the axle in the bearings) doesn't last long--maybe 200 landings, if you're lucky--but it's worth it for the smoothness and piece-of-mind it brings! --RD

[drdehave]

Guys:

We have a few more Sting and Sting Sport owners following this site these days, compared to way back when I first posted this topic. So, I decided to resurrect it--since I just came from the hangar where I was,...you guessed it, replacing the nose wheel snubber on my 2007 Sting Sport!

The symptom: Recently, I was feeling vibrations--the kind you might mistake for "rough air"--up front, whilst flying. Something definitely out of the normal, though.

The confirmation: One of my buds flew up alongside me recently in his Cessna 150, during our joint run for some airport grub. His first words were: "Do you know your front wheel is spinning?" Ah-hah! I should have known that's what it was!

In case you don't have such a 'bud,' and you suspect a free-wheeling nose wheel, you can also strap a GoPro camera on one of the steps; then, fly along at speed with it running and see if your nose wheel is spinning--or not!

The best fix: If you do indeed need to perform that "Nose Wheel Snubber Replacement" drill, here's a free tip: Instead of a short piece of 7/16 fuel line that it says to use as the axle 'snubber,' use a larger (diameter) and beefier piece of rubber hose. Otherwise, you'll be putting 7/16 hose in there about three times as often.

Smooth flying!

Rich

[MrMorden]

I had a similar problem with the mains on my CTSW. The tires had some wear spots on them that set up a nasty vibration at a certain high rolling speed. The vibration would continue after takeoff for some time. The fix in that case was to quickly pull back the brake lever just after rotation to stop the wheels rolling in flight, the vibration stopped instantly.

I have since replaced the tires and it's no longer a problem.

[drdehave]

And, by the way, Sting/Sting-Sport owners:

As long as you're in there--and have to remove the nose-wheel bearings, anyway, to replace the rubber dampening snubber--if the bearings show any issues at all, you may as well just pop in NEW ones, right? At just $2.37 each (two needed), why not? Go here: http://www.vxb.com/page/bearings/PROD/Kit7561 (20x42x12 shielded ball bearing). (Or, you can send about $35 each for them, to our 'other source.')

And as long as you're buying wheel bearings, just to have on hand for if and when needed, you may as well acquire the two per wheel needed for the main-gear wheels, for just $5.77 each. Get them here: http://www.vxb.com/page/bearings/PROD/Kit7568 (17x47x14 shielded ball bearing). (Or, send about $40 each to our other source--and hope they have them on hand when you need them?)

Just some food for $$ planning...

Man, my flight was smooth today!

[bstrachan]

It's best to press sealed bearings out of their housing but I couldn't see any way to press these out. There is a shoulder in the wheel bearing housing so you can't (for instance) just press the outboard bearing out by pressing the inboard one in and letting the spacer tube push the other out. I finally put a 3/4" diameter brass rod through the bore of the good bearing... the 3/4" rod is smaller than the bore and you can cock it inside the spacer tube so the end of the brass rod bears against the inner race of the bearing you want to remove. Tapping the rod with a dead-blow hammer while moving it around on the bad bearing will move the bearing out of the housing. This didn't damage the bearing I knocked out, BTW, although I can't see any reason to remove a good bearing. The SS wheel bearings are sealed and factory lubed and the only service they require is inspection and replacement as necessary.

If anyone knows a better way to get these bearings out of the wheel, I'd like to hear about it.

FWIW, the main gear bearings on my 2006 SS are 42X20X12mm.

[HAPPYDAN]

I had a similar problem with the mains on my CTSW. The tires had some wear spots on them that set up a nasty vibration at a certain high rolling speed. The vibration would continue after takeoff for some time. The fix in that case was to quickly pull back the brake lever just after rotation to stop the wheels rolling in flight, the vibration stopped instantly.

I have since replaced the tires and it's no longer a problem.

Well, Thanks! I occasionally noticed some severe vibration coming from the mains on the C-162 trainer. Sure enough, it has some bald spots on the tires, and sure enough, if I get much above rotation speed on the take-off, (and on too-fast touchdown) there it is. The first time it happened, I thought I had broke the plane! Tech checked it out, said all OK.

[roger lee]

Flat spots will cause the vibration on the ground and flat spots will throw a tire out of balance. All our tires should be balanced with weights. I never put tires on without balancing them and you'd be surprised just how far out some of the tires and tubes are. I have seen twice where I had to put 19 x 1/4 oz. weights on to balance a tire. Of course I didn't leave that and sent the tire back. Sometimes it isn't the tire, but the tube. Normal balance weight has been between 1-2 oz of weight.

[drdehave]

"Flat spots will cause the vibration on the ground and flat spots will throw a tire out of balance. All our tires should be balanced with weights. I never put tires on without balancing them and you'd be surprised out just how far out some of the tires and tubes are."

I would like to "second" everything this man just said. And here's a video you can watch which seems to back up both of us: https://www.youtube.com/watch?v=OqpfFhJax1Y

Rich

[SportPilot]

.......