Page 1 of 2

Balancing wheels

Posted: Tue Sep 24, 2013 10:32 am
by jagarra
This is addressed to the riders have bikes with spoked wheels. Got a set of tires for my R90/6, tires on there were at least 13years old so I got a set of Michelin Active tires. My shop offers free mounting and balancing with a tire purchase, a feature that always provides the incentive to buy all my bike tires there. Got them back yesterday afternoon and was shocked to see a long string of glue on wheel weights on one side on the top edge of the rim. Kind of unattractive for a bike with great patina. Looked like a big caterpillar. Now the wheels prior to the new tires had no weights on them, never noticed any issues, and I did have it up to freeway speed for a few times, not too long based on my concern with the old tire condition. Do you who mount your own tires, balance them or just mount them and ride?
Having mounted and balanced car tires at my home, when I put a tire on the bubble balancer and if it looks like it needs a lot of weight, I break it down and move the tire on the rim until it comes up with a minimum weight requirement.
I went to one of those mail order motorcycle parts sites, was kind of shocked at the price of weights. Heard of wrapping heavy solder on the spokes, what do you do out there?

Re: Balancing wheels

Posted: Tue Sep 24, 2013 11:13 am
by Ken in Oklahoma
jagarra wrote:. . . Heard of wrapping heavy solder on the spokes, what do you do out there?
Heard of the price of solder? :D

More seriously, over the years I've saved all the spoke mounted wheel weights that have come my way on parts bikes etc. That has pretty much gotten me by.

According to Kurvygurl lead wheel weights can still be had--except in certain states.

http://kurveygirl.com/shop/product_info ... QgoddBQA9w

From the website:

NOTICE: Lead (Pb) Wheel Weights CAN NOT be shipped to the following locations due to laws banning Lead (Pb) wheel weights.

USA: California, Illinois, Maine, New York, Washington and Vermont

Europe: All EU Countries (Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Findland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovaka, Slovenia, Spain, Sweekend, United Kingdom)



Also you can buy lead wire at $1.44 per ft for 3/16 wire from here.
http://www.rotometals.com/product-p/lea ... hefoot.htm


Ken

Re: Balancing wheels

Posted: Tue Sep 24, 2013 1:18 pm
by Deleted User 62
+1 on moving the tire around to find a better balance point. Did the tires have a dot on them? I have had good luck lining it up with the valve stem.

Re: Balancing wheels

Posted: Tue Sep 24, 2013 4:42 pm
by Ken in Oklahoma
Tim Shepherd wrote:+1 on moving the tire around to find a better balance point. Did the tires have a dot on them? I have had good luck lining it up with the valve stem.

I have heard Duane talk about balancing tires at a couple Boxerworks rallies. I'm guessing that he covers the same items on his web site. Essentially he goes to a lot of trouble to optimize his balancing with the minimum weights possible. Here are some highlights that I remember:

First check the balance of the bare rim (presumably with rim strap) The light spot on the rim may not be where the valve stem hole is. Mark it permanently in some manner. You will be needing this information in the future. In other words, you need to know where the light spot is on the wheel, not where the valve stem hole is.

Then go ahead and mount the tire and install the tube. Put the mark on the tire at the lightest point where you marked the wheel. Blow up the tire and see what you've got. If little weight is needed to effect the tire/wheel balance you're good to go. But chances are that, given the vagaries of tire construction, the mark on the tire is not reliable. If you don't like the amount of weight it's taking deflate the tire and rotate the tire to another location on the rim. Then re-inflate and see if the weight requirement is more or less. Repeat until you're reasonably sure that you have got the wheel and tire in the best (most balanced) position, and then see what wheel weights are required. This operation may need to be repeated.

Caveat: What I wrote above is what I seem to remember from talking to Duane. (And what makes sense to me.) I did not go to his web site and double check what he says there. The whole point is to optimize the balance before adding a single weight. With some thoughtful additional work you can do a better job of balancing the wheel/tire.

Oh, Duane likes the Parnes balancer. He brought it with him to the rally, anticipating a discussion on the subject. I made my own balancer which I like a lot. Duane compared his Parnes balancer to mine and liked his Parnes better. Using the wheel bearings themselves to do the balancing is not a good idea if only having to do with the viscosity of grease vs light oil. Plus, I reckon that the Timkin bearing has a significantly higher drag than a ball bearing.

Shifting subjects, Duane watched me lightly tapping my balancer with a small wrench. The purpose is, of course, to get the bearing balls moving so "stiction" isn't an issue. Duane asked me if I had one of those electric engraving tools (the kind you use to grave your name on you tools in case somebody forgets they don't belong to him. Duane suggested I used my engraver to vibrate my balancer. (Not the tungsten point, rather the chuck-like do dad that the tungsten is mounted in.)

The high frequency engraver vibration worked noticeably better than my tapping-with-a-wrench method.

Food for thought. To be sure the details of how the job is done is not nearly as important as the thought processes as to what you are doing and why.


Ken

Re: Balancing wheels

Posted: Tue Sep 24, 2013 5:29 pm
by Major Softie
If you have a balancer of any type the first thing I'd do is make sure they actually got it balanced. If not, then you can just make them do it right.

Yes, lead wheel weights AND solder have skyrocketed in price.

The technique you describe of adjusting the tire to get it closest to balancing before adding weight is the far preferred method, but it is seldom done by a shop these days. They mount it, throw it on the spin balancer, and stick on whatever the machine tells them to.

Re: Balancing wheels

Posted: Tue Sep 24, 2013 5:57 pm
by Jean
find lead weights on the street and cut off what you need from them.
They can be hammered, melted....
OR use fishing tackle weights with a slot, for spokes. Of course if you don't live near the sea this can be a bit of a problem finding that sort.

Re: Balancing wheels

Posted: Tue Sep 24, 2013 7:43 pm
by khittner1
Jean wrote:find lead weights on the street and cut off what you need from them.
They can be hammered, melted....
OR use fishing tackle weights with a slot, for spokes. Of course if you don't live near the sea this can be a bit of a problem finding that sort.
This is, after all, a BMW airhead forum . . . :roll:

Re: Balancing wheels

Posted: Tue Sep 24, 2013 7:58 pm
by Duane Ausherman
jagarra, thanks for asking about this issue, as it can be a major factor in a wobble.

Ken, a big thanks for saving me a lot of typing.

I still have lots of the original spoke weights.
Any time that you find you need an ounce of weight to get the balance, it isn't likely correct. I once took a well balanced wheel that had 5 weights and my method got it balanced with no weights.

With the Parnes balancer and a vibrating marker, one can easily measure a gram. We don't need to get closer than a few grams.

To find all of the weights on one side is by itself wrong. They probably should be split up on both sides. It might show up as balanced on our static balancers, but if it were on a spin balancer, it would probably be far off.

Re: Balancing wheels

Posted: Tue Sep 24, 2013 11:09 pm
by sprints@pldi.net
I haven't tried them but I have several friends who swear by Dyna beads - Rod

Re: Balancing wheels

Posted: Wed Sep 25, 2013 12:38 am
by robert
In the early '70s I was on an indi car pit crew at Ontario motor speedway. The speeds were around 180 to 190 mph, maybe more.
I was asked to pick up some wheels at the Goodyear tent and was suprised to see them balancing them on a bubble
balancer that you would see at garage or gas station at the time. It's not magic.