Wheel Balancing

fireman7875

I am new to road biking and went on my first 15 mile ride today. I noticed that above 20 mph or so I feel the bike bobbing and lunging somewhat due to an imbalance in the wheels. I know they are not balanced because if I lift the bike and spin them I can reproduce the effect. My question is how common is this and do any of you take any measures to prevent it? It is relatively unsettling to feel the bike moving under me like that.

Thanks,
Brian

64Paramount

I am new to road biking and went on my first 15 mile ride today. I noticed that above 20 mph or so I feel the bike bobbing and lunging somewhat due to an imbalance in the wheels. I know they are not balanced because if I lift the bike and spin them I can reproduce the effect. My question is how common is this and do any of you take any measures to prevent it? It is relatively unsettling to feel the bike moving under me like that.

Thanks,
Brian

Unless you run over something big enough (like a curb or a big pot hole) to bend the rim out of round (it has a flat spot), or to knock it out of alignment (it wobbles from side to side...will drag against one of the brake pads if bad enough), or break a spoke, that shouldn't happen.

I don't know how many miles you have on your bike, but you should be able to ride several thousand miles without doing much besides replacing tubes and tires.

You also could cause it by over tightening or loosening the spokes, which will cause an out of alignment condition.

I'd take it to your local bike shop and have them see what the problem is. It probably just needs the wheels trued up and then you'll be good to go for a few years.

Bobo 1949

Bicyclists don't normally talk about balancing bicycle wheels. The term of art is "truing" the wheel. Spokes are tightened or loosened as necessary to "straighten" your wheel. Before taking a spoke wrench to a wheel I suggest you do some reading on wheel truing. There are a lot of sources available such as http://www.bikewebsite.com/bicycle-wheel-straightening.htm
The shaking you feel at higher speeds may or may not be related to this particular problem. Get your wheels trued and see if the problem is resolved. Good luck on fixing this.

fireman7875

My bike is new so I am pretty confident the wheels are not out of round. I know the difference between balancing and truing. As I stated, I have confirmed that the wheels are unbalanced by spinning them. Not only can I feel the wobbling but they always settle to the same point. The reflector is causing the imbalance. What I am trying to find out is if anyone else has seen this on their own bike and if so, what did you do about it? Basically, what method did you use to balance it, if any?

Bobo 1949

If you are sure you don't have a truing problem, and to do that you need to use a truing jig, then it sounds like you've a problem with either the axle or the skewer. Neither are likely to fail on a "new" bike. Wheel truing is a much more likely cause. I've never heard of anyone using a weight to balance a tire. I've never seen weights to balance bicycle tires sold in bicycle shops either.
I'm not saying they aren't, just that I've never seen or read of it.
Good luck in solving your problem.

alienator

My bike is new so I am pretty confident the wheels are not out of round. I know the difference between balancing and truing. As I stated, I have confirmed that the wheels are unbalanced by spinning them. Not only can I feel the wobbling but they always settle to the same point. The reflector is causing the imbalance. What I am trying to find out is if anyone else has seen this on their own bike and if so, what did you do about it? Basically, what method did you use to balance it, if any?

Well, take the reflector off.

dhk2

I use balance weights on my Circuit wheels. Shortly after I got them, noticed the bike was hopping while the bike was in the stand and the rear wheel was spun up. Instead of being heavy at the valve stem as I expected, the pinned joint 180* across was the heavy point. The rims use steel pins for the joints, obviously the cause of the imbalance.

Added some wraps of lead soldier to the spokes on either side of the valve stem until the bouncing stopped in back. Then, I duplicated the weight on the front wheel, fine-tuning it until the wheel wouldn't come to a stop with the valve on top, or oscillate when coming to a stop.

Several people have spotted the weights and asked about them, but when I explain how smooth the bike is at 45 mph downhill, or how it grips the road better, they generally roll their eyes and change the subject:)

alienator

I use balance weights on my Circuit wheels. Shortly after I got them, noticed the bike was hopping while the bike was in the stand and the rear wheel was spun up. Instead of being heavy at the valve stem as I expected, the pinned joint 180* across was the heavy point. The rims use steel pins for the joints, obviously the cause of the imbalance.

Added some wraps of lead soldier to the spokes on either side of the valve stem until the bouncing stopped in back. Then, I duplicated the weight on the front wheel, fine-tuning it until the wheel wouldn't come to a stop with the valve on top, or oscillate when coming to a stop.

Several people have spotted the weights and asked about them, but when I explain how smooth the bike is at 45 mph downhill, or how it grips the road better, they generally roll their eyes and change the subject:)

I've never balanced a wheel, but I've never experienced any wheel related issues on 45-55 mph descents.

Bobo 1949

So far the best suggestion has been to take the reflector off.
Huntsville is hilly. I didn't realize you could do 45 mph downhill in that area. Where do you ride, Skyline???

dhk2

I've never balanced a wheel, but I've never experienced any wheel related issues on 45-55 mph descents.
You use better-balanced wheels than the Circuits. With the twin-threaded spokes, they are solidly built wheels, but the rims look like some garden-variety Alex with the heavy pinned joints. If you wind up the rear wheel when the bike is on the stand and the saddle isn't hopping up and down, you're fine.

dhk2

So far the best suggestion has been to take the reflector off.
Huntsville is hilly. I didn't realize you could do 45 mph downhill in that area. Where do you ride, Skyline???
You must be familar with the area. Our club century went over Skyline this year, but climbed from the north side so we missed the big descent. Don't ride there too often. We've got short steep hills all over though. Leaving my house, I ride a block, then turn right and descend, hitting 38-40 mph in about 10 seconds on a 12-14% grade which drops 160 feet.

Many of the steepest descents require braking which spoils top speeds. There are a number of wide-open, smooth pavement descents where 45 mph is the norm; 50-55 isn't hard with a good tuck. Only trouble is that they are over much quicker than the climb up :)

64Paramount

so far the best suggestion has been to take the reflector off.

+1

alienator

You must be familar with the area. Our club century went over Skyline this year, but climbed from the north side so we missed the big descent. Don't ride there too often. We've got short steep hills all over though. Leaving my house, I ride a block, then turn right and descend, hitting 38-40 mph in about 10 seconds on a 12-14% grade which drops 160 feet.

Many of the steepest descents require braking which spoils top speeds. There are a number of wide-open, smooth pavement descents where 45 mph is the norm; 50-55 isn't hard with a good tuck. Only trouble is that they are over much quicker than the climb up :)

It seems like they usually are. We have some exceptions, 'round here, with longish descents. Kitt Peak has a 12 mile ascent, @ a nearly constant 7%, and descent gets fast pretty quick and has lots of turns adjacent to big drop offs...so the descent goes on for a bit. Then we've got Mt. Lemmon, it's a 25 mile ascent @ an average of 4-5%, and the descent.....well, it lasts about as long as you'd like a descent to last, 40-50 minutes.

dhk2

Yes, heard of Mt Lemmon. The locals that go out to Lon Haldeman's PACTour Dessert Training Camp in the spring talk about that climb. Best one I've had in a while was this summer, coming down from Ward to Lyons CO. Must have been 25 miles, just enough drop to allow pedaling in the big gears at 22-25 mph for a long, long time. A spectacular one closer here is from the summit of the Cherohala Skyway going east into the Joyce Kilmer Forest, dropping some 3300 feet in 13 miles, about 4-5% average. Lots of turns, but mostly wide-open with good visibility and great views.

Long, gradual descents are lot's more fun than the scary twisty drops with turns marked at 15-20 mph (if they're marked at all). Those can be really tiring on the hands and forearms after awhile, not to mention the mental focus needed to pick the right lines and speed after a lot of tough miles.

alienator

Best one I've had in a while was this summer, coming down from Ward to Lyons CO. Must have been 25 miles, just enough drop to allow pedaling in the big gears at 22-25 mph for a long, long time.

I'm familiar with that route.