marnan

I bought an inexpensive 700c wheelset to commute to work on. 105 Hubs, Alex R400 rims and 14g spokes that have H on the heads. I have popped 3 drive side spokes in less than the first 100 miles. The spokes are breaking at the threads. This is driving me crazy because the hubs spin so nice. Anybody know what kind of spokes these are ? I suspect the spokes are the problem, just poor quality. I have a good LBS and hopefully they can pinpoint the problem for sure. Don't want to throw good money after bad. any advice would be appreciated.

marnan

Forgot to add that I weigh 160 lbs. so this shouldn't be a weight issue

FBinNY 

Don't know what brand spoke has an "H" logo. It might be Hoshi in Japan, but more likely it's a Taiwanese brand of some kind.

In any case, breaking 3 spokes in the first hundred miles is not a good indicator, unless a stick was jammed into the wheel.

Also thread breakage is not a normal mode of failure, and means something else is going on. Look at the wheel and see if the nipples lie perfectly in line with the spoke. On many rims a tight spoke hole orients the nipple, and doesn't allow it to float to a natural aligned position. Machine building with mis-aligned nipples can stress the spokes at the first thread, and cause your type of failure.

Normally, I always suggest giving the first broken spoke or two a pass and simply replacing and realigning, but the speed, number and type of breakage doesn't bode well, and you're probably better off biting the bullet and rebuilding fresh.

BTW- given how new the wheel is, you might (that's might, so don't get your hopes up to high) have some recourse as a warranty, especially if the nipples are mis-aligned.

marnan

thanks FB, appreciate it. What do you mean by starting fresh? new spokes and a new build or buy a new wheel. It will cost me about $ 75 for new spokes and a new build. I good probably snag a 105 rear wheel with mavic open pro for $ 175.

mrrabbit 

Breaking at the threads?

Please be a little more descriptive...

Are the spokes breaking right where they enter the nipple? Or are the barrels of the nipple breaking right where they enter the rim?


=8-)

FBinNY 

The hub is OK so no need to buy a new one. If the rim isn't the problem (tight mis-aligned spoke holes), and you know a good local builder, save the money and rebuild with what you have. Even if you need a new rim and the price gap gets narrower, a good hand builder should be able to give you a better wheel than a production wheel, with the value of the hub paying for the better work.

marnan

thanks FB. I checked the nipples and most do NOT align with the spokes, so if I understand you correctly, this rim is no good. thanks for all your help and advice

mrrabbit - the spokes are breaking where they enter the nipple

Jeff Wills

Or the wheel was incorrectly built- the spoke holes on the rim are angled to align with the hub flanges. If the wheel was laced so the spokes are in the incorrect holes (i.e. aligned with the wrong flange), they'll work as you describe. It might have happened with a mid-run production change at either the rim factory or wheelbuilding shop. In either case I'd hope it's covered under warranty.

FBinNY 

+1 many rims are drilled to alternating sides to improve nipple alignment. It's possible it was simply built wrong. Also some (rare) also orient the holes not only left and right, but forward and back. This was more common when large flange hubs were popular. Before scrapping the rim, push the nipples into the holes with a pencil eraser, and see how they're oriented. If your wheel was built wrong, it might support a warranty claim, but also means that the rim might be OK after all.

ultraman6970

+1, probably is the right time for the OP to learn wheelbuilding?

conspiratemus1

Following Jobst Brandt's instructions slavishly, I give each pair of crossing spokes (on the same side of the wheel) a firm squeeze toward each other once the wheel has started to develop a moderate amount of tension but before much truing has been done. This improves "spoke line", making a tight (barely visible) bend where the spoke exits the nipple so it runs straight toward the flange rather than staying as a gentle curve that supposedly leaves bending stress in the spoke.

Yes, you do need to be sure that spokes from the left flange are going to spoke holes to the left of the rim's centre-line.

ultraman6970

Holes are lightly to the left or to the right, sometimes the only way to know is because of the angle but i think in the wheels u have u can tell.

U will save some money and you will learn something new that will save you some money also.

mrrabbit 

Whether due to improper lacing (nipples on the wrong side of the centerline) - or excessive crossing - this is a clear case of the angle being such that the edge of the nipple is introducing a stress riser to the spoke...

Hopefully warranty stuff can come into play here...

=8-)

davidad

Low spoke tension can also cause the spokes to break at the nipple. If the tension is right then you need to replace the spokes. Use double butted spokes.

mrrabbit 

Typically they'll break at the heads before they'll break at the nipple insertion point under low-tension conditions...

=8-)