Spokes
 

I was wondering if anyone has had a simular problem to mine. I purchased new this year a Specialized Robaix Expert. It has Roval Fussee EL 28 wheels on it. I have a little over 500 miles on it and the last 3 times I have ridden it I have had a broken spoke in the rear wheel. Each time I had a new spoke put in and the next spoke in line will break. All have been on the cassette side and like I said they have been in consecutive order. I must add that prior to the first spoke breaking I hit a pretty good pothole at about 30 mph and also I weigh about 230lbs. The local bike shop said I should replace the wheel. Ouch! they are'nt cheap.
Any insight would be much appreciated,

Tom

I doubt you need a new wheel.
Machine built wheels often have sketchy spoke tension.
Your weight is not an issue, the pothole may be.
If the rim is not disasterously out of true you may just need to replace the drive-side spokes.
Barring that you can probably get by with letting a good wheel guy properly tension the spokes.

Enjoy

The pot hole did nothing to affect wheel longevity. Bicycle wheels pretty much stand on the lower spokes. When you go over bumps it actually decreases the tension in the bottom spokes.

Your rear wheel was built by a machine with low-tension, non-uniform tension and/or improper stress relieving.

Low tension on spokes allows the nipples to unscrew so they get looser. Loose spokes flex more and fatigue like a paper clip which breaks after you bend it back and forth a few times.

Improper stress relieving allows parts of the elbows to remain near their elastic limit which radically reduces the number of fatigue cycles they can survive.

Excessive tension also reduces the number of fatigue cycles a wheel can survive, although cracks in the aluminum rim are much more likely than spoke problems.

The other spokes have seen approximately the same number of fatigue cycles (about 750 per mile) so you can expect failures to continue in that half of the wheel.

The shop should fix things under warranty.

That would mean re-spoking the drive-side which is failing, bringing it to a uniformly high appropriate tension (100-110kgf is typical), re-dishing, and stress relieving.

If they do replace the wheel with an identical model you'll want the same tensioning, dishing, and stress relieving treatment so the new wheel doesn't fail in the same way.

To the original poster:

As the others have mentioned, your original wheels were built poorly by a machine. In addition to this, I'd like to add that they have too few spokes to handle your weight, regardless of how well the wheel is built. Consider getting a set of 32 or, better yet, 36 spoke hand-tensioned wheels built with quality components. If your bike shop thinks that selling a person your size a 28 spoke wheel is a good idea, you should find a new bike shop.

If you are concerned about the extra weight of a few spokes, then you should realize that: A) You are a 230 pound man riding a bike that has racing-hand-me-down engineering originally designed for 150 pound professional athletes who can afford to treat bicycles and their components like disposable tissues. B.) the weight of 8 extra spokes per wheel would amount to less than a 0.15% total difference in the combined weight of the bicycle and rider.

Basically, you need to get new, stronger wheels. Your bike shop should be taking better care of you and giving you this information rather than charging you again and again to replace spokes on wheels that are completely inappropriate and poorly constructed.

Let's see, bike and rider with a combined weigh of 250 lbs impacting a large pot hole at 30 mph? I doubt that a high quality custom wheel can survive this collision. You're lucky that you didn't flip over and end up on the obituary list. You need to rebuilt the wheel. Stick with 32 h or 36 h wheel for optimum performance. If $ is tight, then you can re-use the old 28 h hub. It apparently was strong enough for daily use until that impact. Make sure the work is done by a good wheelsmith.

Yeah, seriously. I was going to let this slide, but that aspect of Mr. Eckhardt's original assertion is a bit ridiculous. He's correct in some respects about how the physics of spoke tension affect a wheel, but to suggest that a big man on bad wheels has nothing to fear from slamming into a pothole at top speed is pretty laughable.

Thank you all for your thoughts and advise. I should restate that I did not hit a pot hole but rather went up and end drive that was designed for wheel chair access. When I went up it I realized right away that I hit somthing very hard. I have had a new spoke put in and if I continue to have spoke problems I will need to replace the back wheel with somthing more durable.
I am trying to lose 30 more lbs so that should help. I have resently gone thru cancer treatment and beleive it or not I gained about 30 lbs.(major doses of steriods) The new bike was a present from my wife for getting thru a very tough 6 months.

Thanks again everyone!

Tom

Even if you drop 30 pounds a low spoke count is not for you. In fact they are little more than marketing hype ( us boilermakers call that bull****) and not really great for most riders.
A well made 36 hole double butted spoked wheel is what you need.

The wheel is toast. Replace it.

Agreed, and replace it with a wheel designed for carrying more weight.

I checked on Specilized web site regarding Roval wheels. It states that the wheels are designed to be light weight and are recommended for riders 250# or less. Since I fall within those guidelines I am going to try to get my wheel replaced under warranty. Wish me luck!

Good luck!
Keep the 36 spoked wheels in mind for the future. I am not that heavy, but my tourer with 36 double butted spokes has carried my 170 pounds and as much as 50 pounds of gear with no problems. The wheels have over 40,000 miles on them.

Besides a high spoke count, 32, think about the depth of the wheel. The deeper the wheel, the stronger the wheel. Also think about riding on 25 or 28 tires. The wider the tire the less impact the spokes take. Also with a wider tire, you can reduce the air pressure which reduces the impact on the wheel. Spokes break because of metal fatigue. Everytime the wheel goes over a bump or even the undulations in the road, the spokes are squeezed down and then out and deform.

I'm 210 lbs and ride on 32 spoke, deep dish wheels, and 25 tires with a tire pressure of 85-90 in front and 90-100 in the rear.

The spokes undergo a fatigue cycle every time the wheel rotates(about 750 times a mile). Occasional bumps have no significant effect.

Well it seems that Specilized has realized that there is a problem with these wheels. They are sending me a new wheel set. I am not sure which ones, but they said they were about a $400 upgrade from the one that I have. I will post up when they get here and let you know which ones they are.

Specilized did come thru as promised. They sent me a new set of Roval Fussee Star E5's. They came in white and look totally awesome on my white and carbon Rouibax.

Get the wheel replaced under warranty, and spend $60 on a spoke tensiometer. You can then ensure that all the drive side spokes are evenly tensioned @ just over 100kg. Periodic rechecking will let you ride in the assurance that you will be able to complete your rides without broken spokes.

Dont get to excited yet. What is the spoke count on those wheels? Is it 24 up front and 28 in the back? If so, do yourself a favor, don't even ride on them yet. Put them up on ebay or craigslist and get yourself appropriate wheels for you size and you'll probably have a nice chunk of change left over.

Will made some good comments and I am in the low 190 range and I have used deep wheels and I purchased them from excel out of colarodo. they should give you another wheel and/or appropriate replacement.

Just bumping this up again, Thomas did your spokes break like these ones have?
http://farm5.static.flickr.com/4128/...394376a89e.jpgIMG_9593 by ausdb, on Flickr
I weigh 180lb and are having troubles with a set of Fusee EL28's breaking drive side rear spokes and have just made a post about it in this thread
http://www.bikeforums.net/showthread...0-Broken-Spoke
Cheers

Ausdb just in case in these type of wheels with a lot of tension in the spokes, once u get one spoke broken pretty much the next in line will snap and so on and so forth, so probably you will continue snapping spokes unless u change them all. The drive side have more tension than the non drive so is not a surprise you are having this problem. I would replace the whole driver side with new spokes and add spoke washers to it also.

Cheers Ultraman I don't really need to worry about it as my bike is 2 months old and I am pursuing the LBS I bought it from and Specialized to sort it out. I just seem to be finding more threads on various forums of people having issues with Roval Fusee EL28's than other Roval models.
I also happen to have two other wheelsets with 24 rear spokes (conventional nipples) and are not suffering any breakage issues so i think a lot of it has to do with the way these Rovals are put together. The threads of the spoke pass through the rim itself so there is a clear weak point if there is any bending load on the spoke.