# If Straight Pull is so great...



## Enoch562 (May 13, 2010)

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.


----------



## dcgriz (Feb 13, 2011)

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?


----------



## Enoch562 (May 13, 2010)

dcgriz said:


> 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.


----------



## dcgriz (Feb 13, 2011)

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.


----------



## Mike T. (Feb 3, 2004)

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.


----------



## November Dave (Dec 7, 2011)

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.


----------



## Mike T. (Feb 3, 2004)

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.


----------



## November Dave (Dec 7, 2011)

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.


----------



## Enoch562 (May 13, 2010)

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


----------



## Mike T. (Feb 3, 2004)

November Dave said:


> 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).


----------



## Lombard (May 8, 2014)

dcgriz said:


> 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.


----------



## November Dave (Dec 7, 2011)

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).


----------



## Kerry Irons (Feb 25, 2002)

dcgriz said:


> 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.


----------



## roger-m (Jul 1, 2015)

Enoch562 said:


> 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".


----------



## duriel (Oct 10, 2013)

roger-m said:


> 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.


----------



## roger-m (Jul 1, 2015)

duriel said:


> 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.


----------



## dracula (Mar 9, 2010)

Enoch562 said:


> 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.


----------



## dracula (Mar 9, 2010)

November Dave said:


> 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.


----------



## dcgriz (Feb 13, 2011)

roger-m said:


> 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.
> 
> ...


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.


----------



## duriel (Oct 10, 2013)

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.


----------



## dcgriz (Feb 13, 2011)

duriel said:


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


I am not certain if you are referring to my post but if you are I suggest you go back and read it again because your understanding of what you think I said is dead wrong.


----------



## November Dave (Dec 7, 2011)

File under "no good deed goes unpunished." On last night's Thursday night worlds, I notice that the guy who doesn't have the finest hand built wheels in Rhode Island has a wobble in his rear wheel that could seriously make you throw up if you looked at it long enough. Disc bike, no chance the wheel would have fit through rim brakes - reduct the error by half and they still wouldn't have. The wheels came with the bike, the bike is a major brand bike and these are their high end house brand wheels. So I say "hey bring that wheel in tomorrow, I don't want you riding around on that and it's so out I want to check for damage."

So he brings it in.

Straight pull, round spokes, internal nipples. It's like the devil had a menage a trois with himself and this is the offspring. Of course I could see none of this as we were riding, otherwise I'd have told him to take it to the shop where he bought it (which is down the street) and they need to make it right. This is a $7000 bike that's almost a year old. Gets ridden maybe 80 miles/week, and none in the winter. 

So I take the whole thing down to zero tension because it's totally messed up, and then a non drive straight pull head comes off at somewhere around 60 kgf (they're 2:1 laced, so nds has fairly good tension). So now I'm an hour into this total b of a job, having just yesterday said there's no way I'd build straight pull round spokes, only since I offered this I'm doing it for free. Shoot me now. 

No good deed goes unpunished. 

I hate straight pull spokes.


----------



## duriel (Oct 10, 2013)

Never volunteer to work on a disaster, of course it is sometimes difficult to determine from outside.

my other comment was in response to roger-m. If you don't like them, ok, I'm good with one not using them. But to say the whole design is messed up cause somebody somewhere broke a factory made wheel is just wrong. Plenty of J bend spokes have been broken in this world.


----------



## roger-m (Jul 1, 2015)

dcgriz said:


> This is questionable argument in my view.


Nope.

If a j-bend spoke breaks at the elbow, then taking away the elbow with a straight pull spoke solves the problem. This logic is wrong, the straight pull spoke will still fail, but for a different reason, and the explanation I gave is why the OP was seeing many such failures in straight pull spokes.

The mode of failure in straight pull spokes has been discussed many times before (including contributions from Jobst Brandt), although today's better quality steel reduces the number of straight pull failures (and also J-bend failures).


----------



## roger-m (Jul 1, 2015)

duriel said:


> my other comment was in response to roger-m. If you don't like them, ok, I'm good with one not using them. But to say the whole design is messed up cause somebody somewhere broke a factory made wheel is just wrong. Plenty of J bend spokes have been broken in this world.


Hey, all I was doing was giving an explanation why the OP was seeing straight pull heads popping off. It's not a wrong explanation, it's based on metallurgy and engineering. Your one pair of sp wheels that are so far working fine proves nothing.

There's a greater proportion of J bends breaking for the simple reason that there are many times more wheels built with them, and a larger proportion of low cost wheels with poor quality spokes and questionable building.


----------



## duriel (Oct 10, 2013)

roger-m said:


> the straight pull spoke will still fail


mine haven't.
and j-spokes still fail, it has been proven many times.

your reasoning is a fallacy, IMO and I am sticking with my opinion over yours. I'm not trying to change your opinion, I have never seen any engineering papers by a peer review group that has even questioned the validity of my opinion. Until then, good day.


----------



## Mike T. (Feb 3, 2004)

duriel said:


> and j-spokes still fail, it has been proven many times.


Mine don't. I haven't had a j-bend failure since I learned how you properly tension and equalize spokes (aka "how to build properly"). My last broken j-bend would be in the era of 1990'ish.



> your reasoning is a fallacy, IMO and I am sticking with my opinion over yours. I'm not trying to change your opinion, I have never seen any engineering papers by a peer review group that has even questioned the validity of my opinion. Until then, good day.


Yes we all have our personal findings and opinions but Roger will be the last person to tell you this - he *is* an engineer. There, I outed him.


----------



## duriel (Oct 10, 2013)

so am I, are you surprized?


----------



## roger-m (Jul 1, 2015)

duriel said:


> mine haven't.
> and j-spokes still fail, it has been proven many times.
> 
> your reasoning is a fallacy, IMO and I am sticking with my opinion over yours. I'm not trying to change your opinion, I have never seen any engineering papers by a peer review group that has even questioned the validity of my opinion. Until then, good day.


Okay, I'll try again. First read the OP's question...



> 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 gave an explanation. It's not my opinion. It's based on facts. It's been discussed before. It's why sp spokes are not a good solution. I could give you the links to posts made by Jobst Brandt, but I doubt it would change your mind.

Now please explain why the OP sees many sp spokes with their heads blown off. All we've heard from you is that your wheel works, therefore not a problem.


----------



## roger-m (Jul 1, 2015)

duriel said:


> so am I, are you surprized?


Yes.


----------



## dcgriz (Feb 13, 2011)

roger-m said:


> Nope.
> 
> If a j-bend spoke breaks at the elbow, then taking away the elbow with a straight pull spoke solves the problem. This logic is wrong, the straight pull spoke will still fail, but for a different reason, and the explanation I gave is why the OP was seeing many such failures in straight pull spokes.
> 
> The mode of failure in straight pull spokes has been discussed many times before (including contributions from Jobst Brandt), although today's better quality steel reduces the number of straight pull failures (and also J-bend failures).


That's fine but you are assuming a quality build with proper support of spokes at the hub flanges. However, this is not the point I raised . The question I raised was whether a straight-pull spoke has a better life expectancy over a j-bend spoke whose radius has not been adjusted during the building process to allow for proper spoke support at the flanges.

The reason being I see a lot of wheels (mostly inexpensive, machine built j-bend spoked and also some coming out of LBS shops) where the spokes are free-floating and only supported at the j-bend. IMO, if I had to choose I would tend to pick a factory built straight-pull spoked wheel over these.

As I said before, I consider this to be the lesser of the two evils. This preference under these conditions should not be confused with a general preference on straight-pulls which I do not have as I have repeatedly mentioned on this thread. I also believe that a general detriment of the straight-pulls for the custom wheelbuilding community is the accuracy of spoke length from the available spoke calculators. This to me appears to be more of a trial-and-error approach than I would like it to be (contingent upon one's experience with these setups based on production volume) and thus another reason why I have chosen to stay away from building new wheels with straight-pulls.


----------



## duriel (Oct 10, 2013)

roger-m said:


> Now please explain why the OP sees many sp spokes with their heads blown off. All we've heard from you is that your wheel works, therefore not a problem.


Maybe someone is tightening them too tight or too loose? 
He was ranting and didn't really give a breakdown on if it was a build by him, a factory, or an idiot. He didn't give us a study on the tension of remainder of the spokes on those wheels, they types of wheels, the manufacturer, rim nipples or wheel nipples, straight or bladed.

It was a rant and everyone jumped on the wagon. Being obstinant and having built SP wheels and experienced no problems in 20k miles, I am proposing there are other issues. There are plenty of SP wheels out there. Maybe he just doesn't like working on them, I don't care. 

Then posting the implication that the heads were hammered on was just way too much for me. Maybe the manuf process needs to be updated and would solve this problem, I don't care, they work for me, and I am an engineer, BFD.


----------



## Jwiffle (Mar 18, 2005)

I have no input on the metallurgy and engineering of straight versus j- bend spokes, but I can tell you I don't like straight for most of the reasons others have given. 

But here is one more big reason not to like them: you break a spoke, especially if you are away from home, good luck finding a replacement quickly. Most shops don't carry straight pull spokes in stock. Built a set of wheels for a customer who consider straight pull, but when I pointed out any shop will at least have a round silver j- bend spoke that will work to replace a bladed black spoke, but chances are good they will not have a straight, he quick agreed to my recommendation to go with j-bend spokes and hub. 

Sent from my SAMSUNG-SM-J327A using Tapatalk


----------



## duriel (Oct 10, 2013)

Well I always take an extra set of wheels with me, but have yet to use them.

Do you run Di2, eTap, or other wired shifters. I got news for you, they don't have replacement parts for those either. But does that stop one from using them, I don't think so.


----------



## Jwiffle (Mar 18, 2005)

duriel said:


> Well I always take an extra set of wheels with me, but have yet to use them.
> 
> Do you run Di2, eTap, or other wired shifters. I got news for you, they don't have replacement parts for those either. But does that stop one from using them, I don't think so.


Right, but one CAN generally expect shops to have a slew of j-bend spokes in stock. And I certainly get more customers who are passing through with a spoke problem than an electronic shifting problem that needs a part.


----------



## Enoch562 (May 13, 2010)

duriel said:


> so am I, are you surprized?


Yes , Im surprised , I just thought you were a internet terrorist


----------



## Lombard (May 8, 2014)

roger-m said:


> There's a greater proportion of J bends breaking for the simple reason that there are many times more wheels built with them, and a larger proportion of low cost wheels with poor quality spokes and *questionable building*.


I'm guessing this is the main reason for spoke breakage in general. Interestingly, all the spoke breakages I've seen were at the nipple end.



dracula said:


> Only a couple of weeks ago.
> 
> My straight pull Shimano Rs31 spoke on the NDS snapped at the thread/nipple.
> 
> ...


My guess is insufficient tension on the NDS led to more flexing and shortened fatigue life. As pointed out before, the weakest parts of a spoke are at the ends. I don't really know how factory wheels are built, but if built by machine, I can't see how the spoke tensions could be equalized as well as if hand built. If spoke tensions aren't equal, they will equalize as you ride and tensions in general will become slacker. NDS spokes which are the lowest in tension are the most vulnerable. 

What has me really surprised is that you say the wheel was "only slightly tacoed" and you rode it home before you even noticed. Are you saying this was actually rideable? Isn't this a 20 spoke wheel? 

How many miles are on this wheel?


----------



## duriel (Oct 10, 2013)

Enoch562 said:


> Yes , Im surprised , I just thought you were a internet terrorist


Nope, I am not religious.


----------



## rcb78 (Jun 15, 2008)

November Dave said:


> ...they're 2:1 laced, so nds has fairly good tension...


Pretty sure I know what wheels you're talking about, I have the non-disc version. First chance I got I re-laced them with CX-rays. And if they are in fact the same wheels, those proprietary internal nipples only add to the headache.


----------



## dracula (Mar 9, 2010)

Lombard said:


> I'm guessing this is the main reason for spoke breakage in general. Interestingly, all the spoke breakages I've seen were at the nipple end.
> 
> 
> 
> ...


Yes it is a 20 spoke wheel. It hasn't got many miles in it (I took up running and only ride in sunny weather these days). I bought it last year from Ribble on a clearout sale.

I must honestly say I don't know when it happened. All I know is the following: I only noticed it after carrying the bike up the stairs into my flat. I did a 5-6 hour ride on that day.

I don't know what would have had happened if I had broken a spoke on the drive side. The Shimano RS31 is radial on the NDS but cross laced on the DS.

Edit: wrong info and I just checked. Both sides (NDS, DS) are cross laced.


----------



## Lombard (May 8, 2014)

dracula said:


> Yes it is a 20 spoke wheel. It hasn't got many miles in it (I took up running and only ride in sunny weather these days). I bought it last year from Ribble on a clearout sale.


VERY premature. It sure sounds like insufficient NDS tension. There is a small chance it could have been a defective spoke, but I'm still thinking tension issues.



dracula said:


> I don't know what would have had happened if I had broken a spoke on the drive side.


Very unlikely to have a DS spoke break. Remember that your DS spokes will have nearly twice as much tension as your NDS spokes on a symmetrical rim brake wheel. A disc wheel will offset this somewhat as will an asymmetrical wheel. Counter intuitively, spokes will fatigue much faster on the low tension side than on the high tension side due to more spoke flexing.



dracula said:


> Edit: wrong info and I just checked. Both sides (NDS, DS) are cross laced.


This will not make any difference in the stress on spokes. It will only make a difference in the stress on hub flanges.


----------



## blackcat_wheels (Mar 20, 2017)

dcgriz said:


> 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.
> .



Very interesting thread!
As every wheel builder I'm always looking forward to improve my techniques and make sure my wheels live as long as possible.
One question to what you mentioned above - did you mean helping spokes to align on the hub flange properly before tensioning them or something else?

https://www.youtube.com/watch?v=OAOIt2GPzcs

I personally do that before putting any tension to the spokes and after, when tension is about 60%
Any other more sophisticated/more precise way to achieve that?

Cheers
Tomasz


----------



## Lombard (May 8, 2014)

blackcat_wheels said:


> Very interesting thread!
> As every wheel builder I'm always looking forward to improve my techniques and make sure my wheels live as long as possible.
> One question to what you mentioned above - did you mean helping spokes to align on the hub flange properly before tensioning them or something else?
> 
> ...




Welcome Black Cat!

I believe what DC is talking about is tapping the spoke heads into the hub flanges to seat them in properly. Mike T. has a very detailed wheel building website where he talks about spoke optimizing. See below. *Method 5* is what is relevant to this discussion:

Wheels 

*Optimising your spokes - *

*Method 1*. Perform this once only, just after you have got a fair amount of tension in the wheels. Where the "heads in" spokes exit the hubs – take the plastic tipped hammer and tap the spoke bend a little flatter. This does not take much effort. *You can also use your thumb to flatten this curve when lacing these "heads in" spokes. They will reach the rim easier and better.* You're actually bending the spoke where it exits the hub. *You need to do this so that the spoke contains no residual tension due to this curve. Verrrry important!*
*Here is a pic of two spokes - *one, a head-out spoke that doesn't need the neck angle setting and the other, *a head-in spoke that needs the neck angle setting*. You can see the difference in the bends after they have been laced into a wheel, the angle set and wheel tensioned. 

*Method 2*. Perform this after every "round" of truing or tensioning. Grasp parallel pairs of spokes on each side – one pair in each hand - while wearing leather gloves and squeeze them in the hands as hard as you can. Go all around the wheel once.
*Method 3*. Perform once. Take the screwdriver handle and slightly twist the final spoke crosses around each other. Be gentle here. Place the screwdriver handle in the final cross and above it, press down slightly and twist the two spokes around each other. This is not really a "twist" but just a slight, very slight bending. The spokes will do this themselves if you don't do it but then they might lose a minute bit of tension too.
*Method 4. *Do this after each "round" of added tension - press downinto the final spokecrossing, from the rim side of the cross, towards the hub. I use an old screwdriver handle for this (it's my nipple driver above).Use a screwdriver handle, an old LH crank or a wooden dowel (like a 6" piece of old broom handle). 
*Method 5*. Do this once after you have a fair amount of tension on the spokes. Take a thin punch and a hammer. Tap the head of each spoke to seat the head squarely in the hub flange. I said "tap"................not "pound the **** out of". We're just seating the head in the flange and aligning the head.
*Method 6.* Place wheel flat on floor with the rim part nearest to you touching the floor. A piece of cardboard or carpet will prevent the QR from scratches. With hands at 9 & 3 o'clock, press down gently but firmly and quickly. Rotate wheel 1/8th turn & repeat for one full turn of the wheel. Turn wheel over and repeat. The pings you hear are spokes unwinding. But if you have identified and removed all twist, as outlined above in the section "Spoke Twist......" there shouldn't be any left. Check for true afterwards. *Repeat this after each stage or "round"*. You can't repeat this one too often.


----------



## changingleaf (Aug 20, 2009)

I fixed a Specialized MTB wheel with straight-pull spokes and one broke at the head. The next week another broke at the head. The wheels were brand new. I had the customer contact Specialized and they indicated there was a problem with that hub and sent the customer a new wheel.


----------



## roger-m (Jul 1, 2015)

dcgriz said:


> ... The question I raised was whether a straight-pull spoke has a better life expectancy over a j-bend spoke whose radius has not been adjusted during the building process to allow for proper spoke support at the flanges.
> 
> The reason being I see a lot of wheels (mostly inexpensive, machine built j-bend spoked and also some coming out of LBS shops) where the spokes are free-floating and only supported at the j-bend. IMO, if I had to choose I would tend to pick a factory built straight-pull spoked wheel over these.


If you maintain any stats on breakages, it would be useful to note the brand of spokes used. I'd say the quality of the spoke has the biggest effect on fatigue resistance, and most straight pull wheels target the high end market and use decent spokes. 

You could do a simple test, replace a couple of your outside spokes with new ones (same brand and type) that don't get adjusted, don't stress relieve them either, and see what happens. I'd do it myself, but I don't get the miles in these days.



> I also believe that a general detriment of the straight-pulls for the custom wheelbuilding community is the accuracy of spoke length from the available spoke calculators. This to me appears to be more of a trial-and-error approach than I would like it to be


Straight pull spoke calculators are accurate, and no trial and error is needed. I've done quite a bit of work in this area.


----------



## dcgriz (Feb 13, 2011)

blackcat_wheels said:


> Very interesting thread!
> As every wheel builder I'm always looking forward to improve my techniques and make sure my wheels live as long as possible.
> One question to what you mentioned above - *did you mean helping spokes to align on the hub flange properly before tensioning them or something else?*
> 
> ...


Not only to align but also to bend the spoke and get as much support from the hub flanges as possible (lay the spoke flat against the hub flange). The process shown on the video may suffice in some cases however I often find that more effort is needed to bend the spokes enough so they make contact. My personal preference is using a lever as shown here: Wheel Building Tip No. 14 - Set the Spoke Path - Wheel Fanatyk.


----------



## Lombard (May 8, 2014)

roger-m said:


> If you maintain any stats on breakages, it would be useful to note the brand of spokes used. I'd say the quality of the spoke has the biggest effect on fatigue resistance.....


Seriously? So you think this is more of an issue than build quality and proper tension?



roger-m said:


> ......and most straight pull wheels target the high end market and use decent spokes.


I would have to dispute this when it comes to stock road wheels on new bikes. Most appear to be straight pulls whether entry level or high end. Shimano RS-11 and Mavic Aksium come to mind as entry level wheels quite often seen on new bikes.



roger-m said:


> You could do a simple test, replace a couple of your outside spokes with new ones (same brand and type) that don't get adjusted, don't stress relieve them either, and see what happens. I'd do it myself, but I don't get the miles in these days.


Ha! Sorry, not an experiment I care to do. Don't stress relieve or bend spokes in at flanges at all? Wouldn't they go out of true after only a few rides?


----------



## ergott (Feb 26, 2006)

roger-m said:


> Straight pull spoke calculators are accurate, and no trial and error is needed. I've done quite a bit of work in this area.


Biggest area of error is in the crossed spoke calc. Straight pull hubs are almost never an even number cross like 2 or 3, it's decimal. That's difficult to measure (at least I haven't seen a great method) and you are slave to mfg specs which are notoriously suspect. On more than one occasion I've had to rebuild a crossed spoke side of wheel because spoke length didn't turn out as expected. I usually take note of error and make the necessary correction for future builds.


----------



## blackcat_wheels (Mar 20, 2017)

Thanks Lombard, Dcgriz,

So we are talking about the same. I'm using above steps described by Mike and wheel fanatyk (thumb, wooden rod) except tapping the spoke heads with the hammer. 
Need to try it on next build.

Cheers
Tomasz


----------



## roger-m (Jul 1, 2015)

Lombard said:


> Seriously? So you think this is more of an issue than build quality and proper tension?


For fatigue resistance, quality of material has the biggest effect, followed by build quality. Spoke material from the likes of DT is some very well developed stuff.



> I would have to dispute this when it comes to stock road wheels on new bikes. Most appear to be straight pulls whether entry level or high end. Shimano RS-11 and Mavic Aksium come to mind as entry level wheels quite often seen on new bikes.


Fair enough. But I'd say Shimano and Mavic use good spokes regardless.



> Ha! Sorry, not an experiment I care to do. Don't stress relieve or bend spokes in at flanges at all? Wouldn't they go out of true after only a few rides?


It was an empirical fatigue test I proposed, replacing one or two spokes on one wheel. Think more on the lines of knowledge and understanding, and dispelling myths. A tiny adjustment on one (or two) spokes to bring the trueness back is irrelevant.

Same for straight gauge spokes. Quality material gives them fatigue resistance.

My comments relate to DT spokes which I have used extensively. YMMV


----------



## roger-m (Jul 1, 2015)

ergott said:


> Straight pull hubs are almost never an even number cross like 2 or 3, it's decimal.


All Hope Technology and DT Swiss straight pull hubs are an even number cross. Just casually thinking about it, I don't see how you can design one with a decimal cross. Do have an example of an SP hub with a decimal cross.


----------



## Lombard (May 8, 2014)

roger-m said:


> My comments relate to DT spokes which I have used extensively. YMMV


My shop recommended DT as well. When I was doing my builds, they warned me that they have seen far more problems with Sapim and Wheelsmith. Since prices were comparable and I didn't have a set preference, I took their word and went with DT.

To be perfectly fair, I am still a newbie wheel builder and have only built two wheel sets so far. I became interested in wheel building two years ago by reading the forums here and learned a lot from Mike T., DCGriz and your book which I own - thank you! 

Neither of my wheel sets has more than 3K miles yet, so their longevity is yet to be seen. The rear wheel of my first set went slightly out of true at 2K miles. I figured out what I did wrong. Second set has 800 miles and so far, as true as the day I finished building them. My shop was even impressed how good a job I did being so new to all this. (patting self on back) 
</patting>


----------



## roger-m (Jul 1, 2015)

roger-m said:


> Just casually thinking about it, I don't see how you can design one with a decimal cross.


Yeah, you could. But it would be a non standard propriety hub that is wheel specific, and as you say, not easy to work out spoke lengths.


----------



## ergott (Feb 26, 2006)

Any SP hub with paired ears where both leading and trailing spokes are together.

On a J-bend flange the leading and trailing spoke holes are equally spaced around the flange circle.

A decimal cross input into a traditional calc will compensate for the pairing of the spoke heads.


----------



## roger-m (Jul 1, 2015)

ergott said:


> Any SP hub with paired ears where both leading and trailing spokes are together.
> 
> On a J-bend flange the leading and trailing spoke holes are equally spaced around the flange circle.


Once you see how a standard equally spaced J-bend hub morphs into an SP hub, you'll see that there are no decimal crosses involved other than adding 0.5 cross. 



> A decimal cross input into a traditional calc will compensate for the pairing of the spoke heads.


This is guesswork at best. You need to use a calc that is SP compatible. To my knowledge, online, there's only the DT calc, and the WP one that I wrote.


----------



## ergott (Feb 26, 2006)

It's been a while since I used the DT calc, I'll have to revisit it.

In general I rarely use SP hubs. The DT versions have very shallow bracing angle on the drive side. The Carbon-Ti hubs are better in this regard. 

Like many other components, they need to be designed well. SP hubs aren't inherently better than J-bend or vice versa.


----------



## mfdemicco (Nov 8, 2002)

dcgriz said:


> 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?
> 
> ...


Agree, fit at the hub flange is a major weakness of j bend spokes, depending on the skill of the builder to not have an unsupported bend, size and chamfer of the spoke hole in the hub, and flange shape. I this regard, straight pull spokes are superior.

In the OP's issue with broken straight pull spokes, what brand were they? Bad spokes? Maybe the problem is with the quality of the spokes and not with straight pull spokes in general.


----------



## mfdemicco (Nov 8, 2002)

Lombard said:


> My shop recommended DT as well. When I was doing my builds, they warned me that they have seen far more problems with Sapim and Wheelsmith. Since prices were comparable and I didn't have a set preference, I took their word and went with DT.
> 
> To be perfectly fair, I am still a newbie wheel builder and have only built two wheel sets so far. I became interested in wheel building two years ago by reading the forums here and learned a lot from Mike T., DCGriz and your book which I own - thank you!
> 
> ...


I haven't used DT spokes in a while, but found Wheelsmith to have been much better. About 10 or so years ago, DT made an incredibly bone headed move by increasing the elbow length on their spokes. This resulted in the spoke heads not seating in the hub and caused many spokes to fatigue prematurely. They really required spoke washers. The surface finish on Wheelsmith spokes is much better, which also affects fatigue life. I have had less breakage over the years on wheels built with Wheelsmith spokes vs DT.


----------



## Lombard (May 8, 2014)

mfdemicco said:


> I haven't used DT spokes in a while, but found Wheelsmith to have been much better. About 10 or so years ago, DT made an incredibly bone headed move by increasing the elbow length on their spokes. This resulted in the spoke heads not seating in the hub and caused many spokes to fatigue prematurely. They really required spoke washers. The surface finish on Wheelsmith spokes is much better, which also affects fatigue life. I have had less breakage over the years on wheels built with Wheelsmith spokes vs DT.


Interesting. I haven't found the elbow length to be a problem for head seating. And it doesn't appear to be anything a good nail punch can't solve. Since I don't build wheels for a living, I can take plenty of time and do it meticulously. If I had customers breathing down my neck wanting their wheels yesterday, I might be singing a different tune.


----------

