# j-pull vs linear pull spokes



## deviousalex (Aug 18, 2010)

I was chatting with a friend of mine and he seemed religiously against j-pull spokes. He said it was terrible that some companies will really expensive wheels still use them, citing that at the bend is where the spoke is most likely to break. Does anyone have any more information on this? If linear pull is a lot better I'll definitely keep it in mind for any future wheel purchases.


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## aengbretson (Sep 17, 2009)

Well your friend is right, the bend is the most likely spot for failure. Think about it - when a wheel goes around the spokes at the bottom are unloaded due to the weight pushing down on them and then go back into tension for the rest of their trip. This is basically like grabbing the ends of something and repeatedly pulling on it. ANY stress risers (usually changes in cross-sectional shape) decrease the fatigue life of the component and the bend is usually the single largest stress riser in a spoke. So eventually, if the spokes are not properly tensioned or the wheel starts going out of true fatigue will cause premature failure.

That being said, a properly-maintained wheel will last years without any spoke failures. They also cost a LOT less to replace and fix. Try doing that with a fancy straight-pull bladed spoke. You need TWO tools to keep them true (one to keep the bladed section from twisting - something you should be mindful of even if you have round spokes).

Straight pull spokes make "engineering sense" but as both an engineer and a mechanic I don't think you should automatically rule out wheels with j-bend spokes. There are WAY more important things to worry about like internal alloy nipples on tubular wheels (have you tried adjusting a Reynolds wheel? Or even worse freeing up a frozen spoke in one?), carbon layup, and hub quality among others. I'd worry about a ton of things before even thinking about j-bend versus straight-pull (and again nearly any shop in the world will carry a replacement j-bend spoke while most won't have a straight-pull one in stock).


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## deviousalex (Aug 18, 2010)

My current wheelset, Easton EA90 TT have straight pull spokes. I've had two straight spoke breakages but they have both been at the nipple, the spoke itself was fine in both cases.


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## deviousalex (Aug 18, 2010)

Also, what makes the j spokes cost less to replace? Is it the spoke cost or the labour cost?


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## rruff (Feb 28, 2006)

deviousalex said:


> If linear pull is a lot better I'll definitely keep it in mind for any future wheel purchases.


Nope. A well built wheel with J bend spokes should work just fine for many years.


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## Mike T. (Feb 3, 2004)

Straight spokes are a solution looking for a problem.


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## Kerry Irons (Feb 25, 2002)

*Mass production*



deviousalex said:


> Also, what makes the j spokes cost less to replace? Is it the spoke cost or the labour cost?


J-bend spokes are a stock item and are produced in vast quantities. Straight-pull spokes are small volume, proprietary, and often hard to get.


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## Mike T. (Feb 3, 2004)

Kerry Irons said:


> Straight-pull spokes are small volume, proprietary, and often hard to get.


And if they offer no benefit (and I'm open to hearing any) then they're just a marketing tool.


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## Zen Cyclery (Mar 10, 2009)

From what I've heard, straight pull spokes were the original spoke design before J bend. Why they are around nowadays though I am not too sure. We get alot of customers interested in them simply for their aesthetic appeal. 
I find them quite frustrating though simply because they seem to have a tendency to wind up a bit.


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## medimond (Apr 26, 2009)

I've never failed a j-bend ... it failed at the nipple. If it was such a problem the millions of people riding j-bends would be lined up at their LBS everyday.


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## Kerry Irons (Feb 25, 2002)

*Failure*



medimond said:


> I've never failed a j-bend ... it failed at the nipple. If it was such a problem the millions of people riding j-bends would be lined up at their LBS everyday.


The most common failure point for a J-bend spoke is at the bend, and they do fail there. But in a properly built wheel they don't fail often. I think I have had maybe a half dozen spokes break in the last 300,000 miles. However I did once have a wheel that ate spokes because the hub flanges were steel and narrow (SA three speed hub) and it was built with lightweight spokes and rims - that was a big mistake but it allowed me to have a 45 speed bike, which I thought was pretty neat when I was 15.


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## lucyfek (Sep 1, 2009)

It surely failed on my wheelset (vuelta corsa lite). It's also the 1st ever spoke that broke on me. There are many more thing to consider when selecting wheelset.
But straight/linear pull look good and so far no problems on my other wheelsets. You can actually buy these (DT).


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## BWWpat (Dec 17, 2009)

Iv never had a wheel with an issue at the bend, and iv built a LOT (a lot lot) of wheels.


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## Ventruck (Mar 9, 2009)

According to Rolf:
Rolf Prima


> _*Q:Why do you use J-bend spokes?*
> A: Ahh. The age-old question: Straight pull versus J-bend. The J shape of the spoke where it enters the spoke hole of the hub allows it to rotate slightly in the spoke hole under the torque loads coming from the chain/cogs. This movement helps the spoke absorb this input force more easily - increasing fatigue life. If you look closely at many straight pull hub designs, many try to replicate this feature including one that uses 2 flanges per side (4 per hub) with straight pull spokes threaded into brass barrels joining the flanges to allow rotation. In effect, a heavy way to replicate the benefits of a J-bend spoke. We cut to the chase and use the best spoke shape around - J bend._


Kinda says something for a company whose wheels have very low spoke counts (14f/16r).


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