wheel balance

Secrets, tips, tools, design considerations, materials, the "science" behind it all, and other topics related to building the cars and semi-trucks.
Post Reply
User avatar
Scubersteve
Master Pine Head
Master Pine Head
Posts: 199
Joined: Fri Dec 31, 2010 2:34 pm
Location: Milton, Fl
Contact:

wheel balance

Post by Scubersteve »

I have not been doing this very long. In fact, I built my first car less than a year ago, so there's a lot I don't know. I have never balanced my wheels. How much performance am I giving up by this omission? I'm sure it would vary between stock and modified wheels. When I was building my first car I noticed that the wheels used three spokes (Awana). Since I knew that lightening the wheels would help with off-the-pin performance, I came up with this...
Image
I don't have a balancer and I'm sure that it would have been better if I had gotten one and balanced them, but I won anyway. It did cut the weight from 2.2g per wheel to about 1.4g. How much am I leaving on the table here?

p.s. forgive the shoddy finish work on my car. It was my first one, not that subsequent cars have looked much better. Some of you guys do beautiful work. I don't seem to have the patience.
If you don't take your fun seriously, who will?
DenDadBob
Apprentice
Apprentice
Posts: 12
Joined: Sun Jan 30, 2011 2:18 pm
Location: Dallas, Texas

Re: wheel balance

Post by DenDadBob »

I really like the design of the car. I don't have an answer on the wheel balance question, but I would imagine that the lighter the wheel is the less ill effect an out of balance condition would have. Just a guess though.
What kind of wheels are those on the blue car in the background?
User avatar
Scubersteve
Master Pine Head
Master Pine Head
Posts: 199
Joined: Fri Dec 31, 2010 2:34 pm
Location: Milton, Fl
Contact:

Re: wheel balance

Post by Scubersteve »

DenDadBob wrote:I really like the design of the car. I don't have an answer on the wheel balance question, but I would imagine that the lighter the wheel is the less ill effect an out of balance condition would have. Just a guess though.
What kind of wheels are those on the blue car in the background?
Thanks. That was my take on a Oldsmobile Aerotech...one of my favorites.
The car in the background is an open class car. simple balsa with lead molded in the bottom of a coke can. The wheels are 1.5" Dubro microlight airplane wheels with half the spokes cut off. I don't remember how light they ended up. It was pretty fast although we didn't have a timer at the time so I couldn't quantify it.
Image
If you don't take your fun seriously, who will?
User avatar
Scubersteve
Master Pine Head
Master Pine Head
Posts: 199
Joined: Fri Dec 31, 2010 2:34 pm
Location: Milton, Fl
Contact:

Re: wheel balance

Post by Scubersteve »

here's a better shot of my modified awana wheel...
Image
so, how important is balance??? I fully intend to buy a balancer at some point. I'm just wondering how much difference I can expect.
If you don't take your fun seriously, who will?
User avatar
Stan Pope
Pine Head Legend
Pine Head Legend
Posts: 6856
Joined: Sat Jul 05, 2003 7:01 pm
Location: Morton, Illinois
Contact:

Re: wheel balance

Post by Stan Pope »

Given that the wheels are quite light already, it is likely that perfecting static balance of the wheels will yield only small improvements. If the wheels were off on dynamic balance, they might induce some wiggle. If you can't see any "wiggle" in the wheels, these light wheels probably don't get to induce much body oscillation.

As I understand, if static balance is off, then during phases of rotation, the wheel requires more or less energy to make them turn. The effect is the same as if the Cf were increasing and decreasing around the average. That causes the heat time to increase slightly as compared to if Cf were constantly at the average.
Stan
"If it's not for the boys, it's for the birds!"
User avatar
Scubersteve
Master Pine Head
Master Pine Head
Posts: 199
Joined: Fri Dec 31, 2010 2:34 pm
Location: Milton, Fl
Contact:

Re: wheel balance

Post by Scubersteve »

Since I haven't gotten many responses to this question and no numbers thrown at me at all, It raises another question. How many people are balancing their wheels??? Is it standard prep, or do most not bother with it? :scratching:
If you don't take your fun seriously, who will?
User avatar
Stan Pope
Pine Head Legend
Pine Head Legend
Posts: 6856
Joined: Sat Jul 05, 2003 7:01 pm
Location: Morton, Illinois
Contact:

Re: wheel balance

Post by Stan Pope »

A trusted seller of PW wheel balancing gear said, "The Precision Wheel Balancer is most effective on non-lathed wheels, or non-precision lathed wheels. For precision-lathed wheels, such as those we offer, the balancer will allow you to make subtle adjustments on some of the wheels."

In other words, wheel balance is pretty far down the list of issues to address. Most builders probably have worse faults for which correction will yield more performance improvements.
Stan
"If it's not for the boys, it's for the birds!"
Post Reply