Balancing nose wheel of an a/c with tire on.
Any suggestions as to how to perform this operation?
What airplane and why do you think it needs balancing?
Originally Posted by rgruen
I balance all our motorcycle wheels / tires using a simple stand with 2 sets of slightly overlapping sealed ball bearings. The two sets of bearings must be far enough apart that the tire fits between them. An axle passes through the wheel bearings and rests on either side so that the axle can rotate. (Think ferris wheel) Quarter ounce stick on wheel weights are then temporary taped on the inside flange of the rim to balance. Move the wheel 90 degrees after it settles and determine the correct weights so that it will rest anywhere in rotation. Then replace the temorary weights with new stick ons available at any motorcycle shop. My balance stand is made up of bolted slotted angle and works fine. While not perfect, this method worked fine at 175 MPH for the TZ750 I crewed at Daytona.
Originally Posted by rgruen
As a higher cost, lower effort option, you may want to check with your local independent motorcycle or tire shop to see if they can and wish to do it.
Very easy to do if you know the secret:
Wash the bearings clean then lubricate with a very light oil like WD40 or similar. Put it on the axle and tighten just enough to take out the slack and no more. Then just play around with it until you find the heavy side and balance with some small weights (apply half to each side to keep it even.) You'll be surprised how sensitive the method is. Don't forget to grease the bearings again!
99% of the vibration problems I've seen on airplanes have had nothing at all to do with balance. Most have to do with a tire (or tyre) being out-of-round!
Our airplane tires are old bias ply designs not changed much since the 1940's...anyone who learned to drive in the 1950's was warned against hitting potholes and running up on curbs due to the inheriant weakness of bias ply tires which allowed tires to go "out-of-round" and cause a rough ride; landing an airplane hard does the same thing...even sitting too long would cause a tire to flat spot; never to run smooth again!
So before looking for a balance problem prop up the wheel and give it a spin...look for a wobble or an egg shaped runout. If you can see anything but a smooth round run you have a broken ply and no amount of balancing is going to help.
Hope this helps.
Last edited by Hiperbiper; 10-29-2011 at 08:44 PM.
In the 80's, I balanced the tires on my EZ, vezly.
I purchased a round bubble level from Sears.
Fill the bath tub with water to a level that the tires will float.(I left the bearings in, they did not get wet).
Place the round bubble level over the axle hole.
I used stick on mag wheel weights cut to different sizes to balance by placing them on the wheel.
Once balanced, I stuck them on the wheel and rechecked the balance.
Yeah, I would have to argue that balancing does nothing for aircraft that take off and land at 60-80 mph (if that) and are only doing a takeoff roll for 30 seconds.....
uavmx, I had a tire change on my Bonanza, and it was then rough on takeoff. I really disagree with your point that inbalance does not matter. I lift off at 80mph, but if the tire is rough for that time, there are two bad things, First, any shaking can mask a possible engine problem, that is you won't know if it is only the tire until you are in the air. Also any shaking feels bad to the passengers, even if not the pilot. And any shaking causes possible wear and tear on everything in the plane, from instruments to airframe parts and can cause cracks. Obviously not as bad as a prop out of balance because it is short duration, but why have any out of balance when tire balance is easy and not too expensive to correct.
To diagnose a tire being out, notice if it is rough on the roll, but lessens as you lift off. After lift off you can tap the brakes,and it it smooths out then it was a wheel or tire. Tap one brake at a time to see which wheel.
Balancing aircraft tires & wheels
I am constantly amazed at how many ignorant pilots there are in private aviation. My Varieze first flew in 1978, and was built to spec with no modifications when I purchased it 17 years ago. It still had the original super soft main gear, which vibrated front and back badly if the tire pressure was over 35 lbs. After my 1st landing I noticed the tires weren't balanced, so I immediately balanced the tires, thinking that was the entire problem. It helped tremendously and I had no problems with further vibration as long as the pressure was under 35 lbs. It was years later when I realized that no single engine airplanes of any kind had their tires balanced. So it is not surprising to me when I hear comments that it is not necessary to balance aircraft tires, because they are so small or you're only on the ground for 30 seconds or so. Because, EVERY, single engine airplane that everybody has ever flown has vibrated mildly or severely at some point on landing and takeoff ! Try dropping your car at 300 mph on the Bonneville Salt Flats from the height of 1 foot with unbalanced tires. How bad do you think it would vibrate ? Airplane tires are 1/5th to half the diameter of a car tire, so they spin at a much higher RPM and are thus much more susceptible to out of balance vibrations. The front castering wheel on all EZ's and Velocity's are like those little Gyroscope toys we played with as kids, except multiplied by the power of 10. Remember when you spun the Gyro toy and tried to move it off its center, and how out of control it got jumping out of your hand ? Why do we balance ailerons and elevators ? What has taken place in the canard community over the years to solve the fork and front wheel breakage problem, is to make them BIGGER and HEAVIER, which only amplifies the problem. The parts usually survived, but the vibrations got bigger. I've seen front bulkheads ripped out of Velocity's, because of this imbalance problem. And it is so EASY to fix. I just balanced all 3 tires on a 540 Velocity XL, and the test pilot was amazed at what a difference it made. I recently took a fellow Varieze pilot for a ride in my plane;( he flys a Citation for a living ) and he didn't think he needed his tires balanced, until we landed. "You've got to balance my tires", were the 1st words out of his mouth, as we touched down on what felt like a velvet bed. Bubble balancers won't due, it has to be a spin balancer. It is not that difficult to perform, but it is a skill that must be properly taught. Many seem concerned about the wheel weights coming off. This will NEVER happen if the balancer knows how to attach them. I am now performing this service on ANY aircraft tire. So if you want to have safer landings and takeoffs, and stop your teeth from rattlling, just ship me your mounted wheels and tires and bearings, or find a racing go-kart shop and have them balance them for you. I have also developed tubeless wheels for the new Aero 4.00 & 5.00 -5 tires, which allow you to run lower tire pressures that will shorten your landing roll out distance by as much as 2/3's, and doulble the life of your tires.If you have any questions, please contact me at (818)485-7311 or firstname.lastname@example.org Dr.Bob
Originally Posted by rgruen
Balancing Nose Wheel
I was the original poster on this topic.Tthanks for all the replies. Wow, I seem to have opened an interesting topic! I get a vibration after nose whell lifts off. Wheel is going at max rpm then, and it needs to be balanced. SO I am reading with great interest all that has been posted. I would like to just take it to a local tire store and have it dynamically done, but they do not do these smaller wheels. [or I have nopt found a place that does].
Thanks for all the input.
Pelican PL 914 C-GRPW Kelowna BC Canada