How to tell if your wheel has a problem?
 

I've been enjoying the new bike (Spec. Sirrus Comp) and put 500 miles on it so far this year. But my rear wheel has blown a spoke three different times on rides over roughly paved roads. I'm headed to the LBS tomorrow to talk about it . . . how do you tell if a wheel is bad?

For a wheel to break spokes 3 times in the first 500 miles is indeed bad. The wheel needs to be checked for trueness and spoke tension. I'm assuming that the shop did this when they replaced the broken spokes.?

The rim brand/model, number of spokes, type of spoke SB or DB, spoke lace pattern, spoke tension, and rider weight are all wheel longevity factors..

I've never broken a spoke. What happens? Does it break at one end, and just stick out until you realize it and fix it? Is there a sound when it breaks? Do they break near the hub, near the tire, or both?

Deeg, I think it can be all of the above. Many years ago, I had a front wheel of a new bike completely collapse as I was making a turn at maybe five mph. The bike shop replaced the wheel with no questions asked.

The only other spoke that I've ever broken was near the end of a 5.500 mile fully loaded bike tour across Europe. I didn't know even the spoke had given up the ghost until I stopped for a break.

When you think about the stresses they withstand and how rarely they fail, it's amazing how well-engineered bike wheels are.

The one spoke I broke was at the hub. When it snapped it sounded like I had hit a small rock just right to get it to pop out from under the tire. The wheel immediately went out of true enough to rub on the brake pads. I shortened the ride and went slowly back to the truck. All I really knew at the time was the wheel wasn't round anymore. Quick inspection showed a broken spoke which rang the bell in Mr. Oblivious's head on the snapping sound I'd heard earlier.

Most traditional spokes break at the elbow where they enter the hub. Low spoke tension somewhere on the wheel is the usual cause. As a spoke moves around in the hole in the hub, the stresses go back and forth at the elbow causing metal fatigue and eventual breakage. The spokes most likely to break are the rear wheel spokes opposite the cassette because the offset (called dish) of the rear wheel to provide clearance for the cassette makes these the lowest tension spokes on the bicycle.

There will sometimes be issues that cause spokes to break elsewhere but this is by far the most common cause. A well built wheel should go for thousands of miles before breakage.

The wheel is the stock Jalco that Specialized apparently switched to with its 2007 models. The spokes are straight pull, and I replaced the first two. From day one, the wheel makes a subtle creak under a load -- when I'm on it. The noise isn't there just spinning the wheel on the stand. My diagnosis is several spokes are under-tensioned and under a load the spokes are popping out of the hub sockets slightly.

The first broken spoke happened as I was coming home and made a very loud "pop" -- I thought it was the tire hitting a rock. The break occurred about 1/3 of the way out from the hub, and my initial reaction was defective spoke. I replaced it with a spoke from a bike shop close by.

After installing the spoke, and while checking the wheel for true, I attempted to tighten several spokes which seemed loose. Most simple spun around without any adjustment, which is a little annoying. The second break was one of these "adjusted" spokes and in the neighborhood of the first broken spoke -- just above the nipple, and happened while on the road to Denver. The bike wrench in Denver thought I probably damaged the spoke while adjusting it . . .:rolleyes: . . . or popped it while loading or unloading the bike! :o

The third break happened Sunday. I did not notice the actual break, but as I loaded the bike I heard a rattle in the wheel and realized it was the nipple rolling around inside. I noticed several spokes on either side are loose, although the wheel rolls without rubbing the brakes. So this time I'm heading to the shop which sold the bike to talk warranty/repair/replacement. I've never popped a spoke before, so I'm convinced something isn't right with this wheel.

I appreciate everyone's contribution to this -- it all helps as I get ready to visit the bike shop.

I've heard many times that stock wheels on bikes can be machine built, and can have problems with spoke tension. I had a problem on the rear wheel on my recumbent. The shop went over the entire wheel just like building one by hand, and it's been great since then.

Exactly. A wheel that won't hold true is another symptom of uneven tension.
Easy solution is to loosen all spokes to slack and evenly re-tension to true.
At that point it's effectively a hand built wheel and should go thousands of miles with little or no attention.

I don't break spokes but my 200lbs mate did when he first got his bike. The lbs did a good job on reapairing the first couple then they said it was a faulty wheel and got Giant to replace it.

High praise for my LBS! Stopped in, expecting to have to leave the bike since this is a busy maintenance season and was told there is a week backlog of getting tuneups. Instead, both mechanics took a look at the wheel, determined the rim and hub looked good. Then one of them proceeded to loosen everything up, put on the truing rack and spent an hour replacing the missing spoke and re-working the wheel. And in the end, charged $14.95 . . . remarkable service! And I'm back on the road without much of a break -- life is good!

Now if I can just figure out how to tell the wife how much more I spent on the goodies I found while waiting! :rolleyes:

Danger....danger Will Robinson...... Never, never, never wait in a bike shop while an inexpensive repair is being made. There is a reason they can do it so inexpensively......and with a smile.

They don't have to explain anything to your wife.

Most new bike wheels are machine assembled/built. Have bike shop put wheel(s) on trueing stand and true each wheel. Then ask them to 'stress' each wheel at least twice.
Have had a well built wheel last 56,000 miles on the front of our tandem with never a problem except for a couple minor trueings.
Hats off to your LBS!

While talking with the mechanic about the wheel, we concluded part of my problem is the quality of the roads I ride. During the last ride, I covered a 2-mile stretch of "paved" road that just beat me to death. The base was cracked like a dried mud flat and the patch coat was even worse -- it would have been much better left as a gravel road. The vibration was so bad my wired bike computer quit working!

So the lesson is the wheel was probably not tensioned right to begin with, and the bad roads are bringing these flaws to the surface. The bright side is this is an excellent "proving grounds" as I get used to the new bike and once everything is dialed in I'll know the bike will be ready for just about anything. :D

Those straight pull spokes are hard on the body and hard on the bike. Properly built and they can be a strong wheel that can take everything you can throw at them but they are not a user friendly wheel on rough tracks and roads.
I had them on the Giant when I got it last year but recently got my LBS to build me a a pair of hanbuilt wheels. They put together a pair of wheels that the more serious rider would call a "Training wheel" and they are superb. Good hub- Good rim and the spokes are crossed X 2. just enough give in them to say that I ride in the saddle more than I used to.

Incidentally- On the MTB I have a pair of Mavic Crossrides that are straight pull and for the serious Events I use them. Good strong wheel that works. Not a good wheel for over 50 miles though.

stapfam,
I never thought about spoke pattern related to ride quality, but it makes sense. Looking at my back wheel, at any given moment 2 spokes are straight between the ground and the hub, and the opposite spokes are in a straight line, so there are no lateral diffusion of force -- very little give between road and axle. The front wheel has fewer spokes, so generally only one spoke transfering pressure from road to axle.

Makes me wonder if a different spoke weave would give a "softer" ride?

Something to ponder on tonight's ride!

It would be possible for your LBS to change the spoke pattern to a crossed spoke but this would require a wheel rebuild and that would not be cheap. What might be a better alternative is to look around for a good wheel builder to build you a set of wheels as your first upgrade. This may be at your LBS but look around to get a sensible wheel at a sensible price. Then you will have a set of wheels that will give you a performance boost and also have a spare pair of wheels for those nasty wet winter days whan water getting on the rims and in the bearings could wear them out prematurely.