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Discussion Starter · #1 ·
Why is it when someone calls and ask me to replace a spoke on the Straight Pull wheel, it comes in with the Head blown off? I thought this was supposed to be the cure for that?

I just don't see where straight pull spokes are really any better... Rant Over.

 

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Would the same spoke on the same wheel, built exactly the same way and ridden the same exact way, break at the bend sooner if the spokes were j-bends?
 

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Discussion Starter · #3 ·
Would the same spoke on the same wheel, built exactly the same way and ridden the same exact way, brake at the bend sooner if the spokes were j-bends?
Hard to say...

I get the theroy of straight pull, it might b lighter, there may even be some geometric advantages of hub design. I'm just not sold on it. All the force is still going to each end of the spoke wether it is straight or J bend

I did have a ENVE wheel come by the other day that broke a straight pull at the rim (internal nipplels). I still see more headless straight pull ones.
 

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I am not a fan of straight pulls either but mostly for the reason of being a royal pain in the arse to build with.
The theory on the advantage of the straight ends vs. the bended ends relative to strain etc. sounds reasonable but I dont have j-bends breaking often enough to justify dealing with the hassle of keeping the straight-bends steady so they dont wind-up during tensioning. I dont see j-bends being an underlying problem on a properly built wheel.
 

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If spoke heads are the achilles' heel of spokes then wouldn't it make sense to have no heads? Enter, the Velomax hub with not a spoke head anywhere!

I have one of these rear hubs, gifted to me by the late great tool-maker Paul Morningstar. He sent it to me with the comment "If you can figure out the formula for spoke length, let me know as I have a few of these hubs and don't have the time or ambition to do it myself".

As I could foresee a whole load of issues that made the problem of the occasional j-bend head popping off seem irrelevant, I never did figure it out for Paul. Here the hub sits! IMO it was a solution looking for a problem.

Bicycle wheel rim Spoke Rim Bicycle accessory Bicycle part
 

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That hub is what got me started in wheel building! This is sort of a funny one. It was my first Cat 4 race, a flat fast crit in a parking lot (RFK Crit for anyone who's raced in DC) and a guy put his front skewer into my rear wheel two turns from the finish. Broke several spokes. Two of them were broken off like right at the hub flange, and try though I might - and I'm generally wicked resourceful about figuring stuff like this out - the spokes would not come out of the flange for anything. I bought a hub second hand from a guy on the team who'd destroyed his rim, and was on my way.

The guy whose front wheel did the damage wound up building like 100 wheels for us when we were just starting out. Excellent wheel builder. Alas, he got a real job and moved to China to work for Oracle, as I recall.

I find most straight pull hubs actually have worse geometry than j-bend, but like most things there are good and bad examples of each. Waiting for a set of rims to build these up, by customer request. Machine Trigger Silver Gun accessory Gun barrel
 

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My first reaction to seeing this hub in my hand was "How the hell do you get a broken (flush) spoke end out of the hub? I did research that as I couldn't imagine having to chuck a hub away that had one broken spoke. The info it out there and it suggests, hair dryer for heat, needle nose vise-grips for the threaded part (that sticks down through the flange) and a boat load of patience. It make a snapped-off j-bend head seem like a walk in the park.
 

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Well hopefully the next guy to Google search that topic will find this thread and learn that the answer to a spoke broken off close to the flange is to save your time and spend your money on a new one. My next step would have been to drill out the broken spokes and every other drive side hole and replace the threaded-on-both-ends spokes with normal straight pulls, but I got sane before that happened.
 

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Discussion Starter · #9 ·
I guess the good thing about Straight pull is if your lucky enough to break a spoke at the nipple, you can easily remove it even with disc brakes. You just push it thru the hub with no cssette or disc removal, unlike those pesky j bends
 

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Well hopefully the next guy to Google search that topic will find this thread and learn that the answer to a spoke broken off close to the flange is to save your time and spend your money on a new one. My next step would have been to drill out the broken spokes and every other drive side hole and replace the threaded-on-both-ends spokes with normal straight pulls, but I got sane before that happened.
This is why I don't get into oddball (aka dumb-ass) hub ideas. I can't say a j-bent spoke has ever caused me a problem (based solely on its bend over a non-bent spoke).
 

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I am not a fan of straight pulls either but mostly for the reason of being a royal pain in the arse to build with.
The theory on the advantage of the straight ends vs. the bended ends relative to strain etc. sounds reasonable but I dont have j-bends breaking often enough to justify dealing with the hassle of keeping the straight-bends steady so they dont wind-up during tensioning. I dont see j-bends being an underlying problem on a properly built wheel.
This. Especially trying to true a bladed spoke wheel without turning the hub end of the spoke.
 

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Would the same spoke on the same wheel, built exactly the same way and ridden the same exact way, break at the bend sooner if the spokes were j-bends?
J bends tend to bread due to flexing, not overall tension. Threaded ends represent a stress riser. You takes your choice. We're well over 100 years into J bend spokes. Something must be working OK.
 

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Why is it when someone calls and ask me to replace a spoke on the Straight Pull wheel, it comes in with the Head blown off? I thought this was supposed to be the cure for that?

I just don't see where straight pull spokes are really any better... Rant Over.
The straight pull spoke is not a better design.

A straight pull spoke has its head forged on which disrupts the grain structure making it weaker in that area. When the spoke is used, all the tension is taken directly on the already weakened head area, so failure is more likely.

A J bend design is much better, since the forces at the hub end are taken by a stronger part of the spoke and not taken directly on the spoke head. Okay, they may fail (due to poor building technique), but saying a straight pull design will prevent this is false.

Edited for clarity. Word "mashed" replaced by "forged".
 

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A straight pull spoke has its head mashed on
Just to clarify, exactly how do u know this?

Your statement implies that there is a box of spokes and a box of heads on the assembly line, I find that highly implausible and therefore the remainder of your post is also highly suspect.
 

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J
Your statement implies that there is a box of spokes and a box of heads on the assembly line, I find that highly implausible and therefore the remainder of your post is also highly suspect.
The end of the spoke blank is forged to make the spoke head.
 

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Why is it when someone calls and ask me to replace a spoke on the Straight Pull wheel, it comes in with the Head blown off? I thought this was supposed to be the cure for that?

I just don't see where straight pull spokes are really any better... Rant Over.

Only a couple of weeks ago.

My straight pull Shimano Rs31 spoke on the NDS snapped at the thread/nipple.

Btw: The wheel was only slightly tacoed and only when at home did I notice it. However, the ****ing **** was there was only one online dealer in the entire UK who just happened to have on in stock (all the local bike shops wouldn't have been able to source it before August 2017 as the main UK supplier is just lazy).

I don't know why the **** snapped at the nipple and why it broke at all.

Edit: it was impossible to use the old nipple because the spoke broke at exactly the edge level where the nipple ends. Local bike shop had no way to remove the remaining broken spoke. I was lucky not just to source a spoke but also a new Shimano RS31 nipple.
 

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Bladed spokes actually give you your best chance, as you can use a holder. I won't build a straight pull wheel with round spokes (at lest for what anyone would pay).
Do straight pull round spokes actually exists?

I always thought every straight pull spoke is ,,bladed" in a way or another.
 

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The straight pull spoke is not a better design.

A straight pull spoke has its head forged on which disrupts the grain structure making it weaker in that area. When the spoke is used, all the tension is taken directly on the already weakened head area, so failure is more likely.

A J bend design is much better, since the forces at the hub end are taken by a stronger part of the spoke and not taken directly on the spoke head. Okay, they may fail (due to poor building technique), but saying a straight pull design will prevent this is false.

Edited for clarity. Word "mashed" replaced by "forged".
This is questionable argument in my view. Proper building requires that the j-bend elbows are bent to lay properly on the hub flange for support. If they are not, their fatigue life usually decreases and the spoke breaks prematurely. Setting the right spoke angle on j-bend spokes takes a bit of time and knowledge as its affected by location of spoke (inside or outside) and hub design. Often is not done or done half-arse and spokes break.

The straight-pull spokes, on the other hand, appear to overcome this "custom" fitting necessary with the j-bends as their design makes their placement standard for all hubs and spoke locations. So from that prospective are they more forgiving (decreased fatigue cycle life wise) when compared to a j-bend spoke where the builder did not take the time to bend the elbows right?

Straight-pulls also come with their own baggage of problems and wind-up is one that made me look elsewhere as I will not do them again unless they are bladed.

Which is the worst between the two evils? Do the straight-pulls better guard the average consumer against premature spoke breakage from poor quality builds? I find answers will vary.
 

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I rebuilt my Eastons with straight pull DT swiss spokes, haven't had a problem. The original build spokes were a disaster, IMO.

Calling this design an error is just ridiculous, sounds like they all have problems if not installed with care.
 
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