IPassGas

My sister had her rear wheel respoked and within a few hundred miles 2 drive side spokes broke at bend. The pattern on the head is a 5 lobe flower, perhaps Hsing Ta Industrial spokes? Are these high quality spokes? Of course, other factors may be at play such as too low tension.

GamblerGORD53

DeFaileur bike I presume. There is only ONE solution. Get Sapim or Wheelsmith 2.3/ 2.0 mm spokes for all the drive side. Better yet also get locking nipples and tighten properly.
Anything else is doing the same thing over and expecting a diff result.

Rick

[QUOTE][My sister had her rear wheel respoked and within a few hundred miles 2 drive side spokes broke at bend. The pattern on the head is a 5 lobe flower, perhaps Hsing Ta Industrial spokes? Are these high quality spokes? Of course, other factors may be at play such as too low tension./QUOTE]

Send pictures: We need to see the problem.

IPassGas

Sorry, difficult to take photo of spoke head. I'm asking about the quality of Hsing Ta spokes.

FBinNY 

Far too many possibilities for even an educated guess, though I doubt it was a spoke quality issue.

However. I am curious your logic on one point. You said drive side spokes failed, possibly from low tension. Given that drive side tension is considerably higher than the left, wouldn't a low tension issue be more likely to manifest on the left?

In any case, not knowing anything else, I'd more likely blame the builder, and suspect failure to properly set and stress relieve the elbows, which is the most common cause of short wheel life.

Otherwise; poor spoke selection (type not brand) ill suited to the needs, excess tension, extremely uneven tension, unknown event, and so on.

BTW- please help by adding your experience to my spoke breakage survey here on BF, thanks

Rick

[QUOTE][Sorry, difficult to take photo of spoke head. I'm asking about the quality of Hsing Ta spokes./QUOTE]

You stated the spokes broke at the bend not the head. A picture of the hub were the bends are. Reasons for spoke breakage. Spokes to loose, Thin hub flange that knives the spokes And other assorted problems.

sweeks

I think the "head" is of interest here because of the identifying marks for different manufacturers.
Spoke Head Identification Chart

Garthr

I guess you're referring to what's known as HT spokes ? If so I see nothing of an "industrial" version. What does that mean ? https://htspoke.com/spoke.html

Even regardless of that I suspect a poor wheel build. If they are HT spokes of some variety I seriously doubt they could be so poor that they'd break that fast unless the wheel is very poorly built, or the spoke holes are jagged or some other factor unrelated to the actual spokes.

IPassGas

The wheel was poorly built, incorrect dish and from my feel of drive side after discovering breakage, too low tension. My sister should have had the spokes rechecked after 100 miles, that is on her. However, she ask for high quality components on the previous rebuild. The wheel builder was not good but I also suspect he used low quality spokes. I suspect she will eventually need another rebuild from a competent person, but we are currently travelling and biking in different places.

Andrew R Stewart 

No comments about the rim's contribution to the issue. If the rim had a flat spot from previous use (and the OP used "respoked", to me suggesting a not new rim) then the spokes within that flat area would likely be of lower tension than their neighbors were. If the rim had some significant lateral issues again some spokes will be of different (higher or lower) tension than the far more consistent tensions a good flat and round rim will end up with.

Some shops won't relace a used rim due to the greater chance of later problems and that these revisiting problems are now the fault of the shop. One way to try to figure out the rim's untensioned condition is to loosen all the spokes just enough so that there's no aligning tension but the rim is still held in place. Spin the wheel looking for the usual out of true condition. If the rim does have a problem area it will often show when the spokes are no longer trying to realign the rim straight. Andy

FBinNY 

We're all throwing stuff against the wall to see what sticks. There's simply not enough info to point to anything except a poor build.

From the context it SEEMS to be a case of an emergency rebuild on a tour. If so, important clues would be; what happened to the original wheel, how far into the trip did it last, was the rim reused, what is the load, butted or plain spokes?

If the OP wants usable help, I'd focus on options going forward, most likely identifying a reliable shop along the way, and limping to it. If the OP tells where they are, and where theyre headed, possibly someone could suggest a decent shop.

easyupbug 

Yes. When working in Australia Hsing Ta was the hot set up for for their range of bicycle components (and motorcycle), my current 2 MTBs have their outstanding pedals. I recall their spokes for MTB and motorcycles were Sandvic stainless steel.

Russ Roth

Locking nipples? Seriously? Spoke prep isn't really even needed on a properly built wheel which, if done right with good materials, still won't have nipples come loose.


OP: as FBinNY rightly points out, there isn't enough details to know what the real issue might be other than a poor build and i would first suspect that as well. It sounds like its a touring bike but if so is this the first tour on it or has it been around for a while? if new, are you discovering that the rear wheel isn't designed for some combination of the load, road conditions or riding style? Did the wheel fail from old age with repeated spoke breaks and maybe the rim is too fatigued at this point that it shouldn't have been rebuilt and is making for a weaker overall wheel, similarly, were the spokes damaged in a crash meaning the wheel shouldn't have been rebuilt and again is too weak. Too high a tire pressure and impacts are creating problems? With a stronger rim this dents/deforms the rim but with a softer rim i've seen this break spokes instead. Although spokes can be a problem, i wouldn't assume that the average modern spoke is the principal issue if new, even the cheapest department store bikes tend to go far more than 200 miles without breaking spokes.

mrrabbit 

Hsing Ta's are budget low grade stainless steel. Don't stress relieve em after a build or replacement, they're going to break very soon.

Stress relieve em and they can go a year or even longer.

Doesn't help either if the spoke elbows are 7.0mm instead of 6.2mm.

First things first, give the entire wheel several rounds of stress relieving using the super squeeze method with a pair of thick gloves.

This will expose any more spokes likely to break.

Then replace the few again...stress relieve...give it another try.

However, if you discover that you are now having to replace 5-6 spokes instead of just the one's already replaced....you're better off rebuilding the entire wheel or replacing it.

=8-|

easyupbug 

Surprises me in that all of the testing i have seen failures are all +130 KgF, which i would think would causes issues with rims and nipples first and my Nukeproof wheels set used Sandvik 302T spokes as does Hsing Ta.

FBinNY 

FWIW 302 stainless, though slightly cheaper, is actually stronger than the 304 (18/8) typically used for spokes.

304 is preferred not for strength, but for slightly better workability, and much better corrosion resistance.

If it were only about strength, there are many better alloys, but they've gone out of favor because of things like the need for plating or painting, and lousy long term cosmetics.

In any case, the extremely short life of this wheel pretty much rules out spoke quality differences.

mrrabbit 

Spoke breakage can be tested in your own garage.

1. Put steel anchor L-plates in a vise - the bend in the L-plate will be rounded to avoid shearing. (You want a bend test - compression/decompression - NOT a shearing test.)

2. Lightly clamp spokes between the plates - enough to bend the spokes without them coming loose.

3. Bend to one side, second later, bend to other side...rinse repeat while counting.

Record for each brand - gauge - and finish (polished or black-oxide) - the breakage point count.

Of course, can't just do one for each - gotta do at least several for each. I typically go 5-10 each.

Record results on a chart.

The difference between DT Swiss polished / Sapim polished VERSUS CN / Pillar / Wheelsmith polished VERSUS Hsing Ta's and other budget spokes from China and India will really stand out.

What's really cool that in the three decades plus I've done this kind of testing - there will be that occasional obscure name brand spoke from who knows where that does just as well as DT Swiss - and costs 10 times less because of its obscurity. Perfect example were OHIO spokes sold by Trek in the late 80s / early 90s. They could be had for a penny each while DT Swis were 10-15 cents each - yet held up just as well.

I do the test above about every 2-3 years - with about 200 spokes each time. Several manufacturers will send me samples for testing each time.

So far, DT Swiss has been the consistent winner each and every time. They never donate however...

The above test is MACRO in nature. Of course, in the real world it's MICRO and occurs for tens / hundreds of thousands of cycles on our bicycle wheels before breakage occurs.

=8-|

The true test of a spoke is not tension - it's its ability to handle compression / decompression cycles over time before it fatigues to the point that it reaches a brittle state whereupon it snaps.

You'll notice after a spoke breaks the the area around the breaking point has hardened from its previous "elastic" point.

IPassGas

Thanks for all the replies. mrrabbit...thanks for all the testing and results, seems like useful a chart that many would appreciate.

The spokes have been replaced, the rim centered (dish was way off) and the wheel bought to a higher overall tension. I have encouraged my sister to find a competent wheel builder when back home and to specify better spokes when the wheel is rebuilt.