# Straight pull versus j-bend



## Pirx (Aug 9, 2009)

Here's another one I have always wondered about: Conceptually I really like the idea of the straight-pull spoke. On the other hand, I also understand the unparalleled flexibility that the j-bend spoke afford the builder, by allowing a variety of lacing schemes even with the identical hub and rim. So my question really is: Do straight-pull spokes have tangible benefits? Other than perhaps saving five grams for a wheel? Are wheels built with them (ever so) slightly stronger? Stay true longer? Or are they just gimmicks? Serious question guys, not trying to start a flame war.


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## Mike T. (Feb 3, 2004)

Of course you're going to get opinions. IMO they're a solution looking for a problem. I can't remember a bend in a spoke causing me a problem ever since I figured out how to build wheels properly (which would be about 20 years ago after 30 years of building them not properly).


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## jfaas (Jan 31, 2014)

I think Mike nailed it. Build it right, you will have a very low chance of failure. No need to worry about the bend.


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## coachboyd (Jan 13, 2008)

I had asked this question to a bunch of wheel builders off forum as we are developing some mtb hubs. Every single one said jbend due to the flexibility. 

Another good point t brought up by Dustin at Southern Wheelworks. He built up a straight pull hub with round spokes and said Never Again!!.

The spokes just spin and it's hard to keep them in place without pliers. Bladed spokes are not as bad.


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## dcgriz (Feb 13, 2011)

It seems to me that the case of the straight pull spokes was created by the majors to address issues resulting from the quest of continuously attempting to reduce the number of spokes. Issues like loss of lateral stiffness (hubs with straight pulls tend to have better bracing angles than j-bend hubs), higher tension values at the (less spokes = higher tension per spoke) and spokes made from other material other than steel (beefy bladed aluminum spokes used by Mavic, Fulcrum, etc). 
I think when looked at from that prospective the need of straight pulls may be easier to justify. 
The wheels I personally build don't use less than 28 conventional spokes at the rear (conventional in the sense of either thinner bladed spokes like the Cx-Rays or round double butted like the Race). For these kind of builds I don't see the benefits of the straight pulls justify the hassle of building using them.


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## smokva (Jul 21, 2004)

coachboyd said:


> I had asked this question to a bunch of wheel builders off forum as we are developing some mtb hubs. Every single one said jbend due to the flexibility.
> 
> Another good point t brought up by Dustin at Southern Wheelworks. He built up a straight pull hub with round spokes and said Never Again!!.
> 
> The spokes just spin and it's hard to keep them in place without pliers. Bladed spokes are not as bad.


Exactly what I concluded after building one wheel with straight pull spokes. They spin like crazy. It is bad design, spoke head and flange hole shouldn't be round on straight pull, but if they make it in some sort of shape which would sit firm it would probably add to the cost and make it less strength.


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## Jay Strongbow (May 8, 2010)

I don't know but I suspect that with Shimano's engineering resources leading them to use straight pull and their ability to make low spoke wheels that actually do hold up probably indicates there is something to them.
Maybe it's not straight pull per se but the bracing angle they allow for. I'm not trying to promote Shimano wheels as there are issues to consider but I think it's pretty clear they are stronger then a traditional set could be made with the same amount of spokes.


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## changingleaf (Aug 20, 2009)

I've seen both straigh-pull and j-bend spokes broken at the hub and I can't find any fatigue testing showing that one is stronger than the other. 

From the measurements that I've taken straight pull hubs do not necessarily have a better bracing angle then j-bend designed hubs.


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## dgaddis1 (Sep 27, 2008)

changingleaf said:


> I've seen both straigh-pull and j-bend spokes broken at the hub and I can't find any fatigue testing showing that one is stronger than the other.
> 
> From the measurements that I've taken straight pull hubs do not necessarily have a better bracing angle then j-bend designed hubs.


This.

You can build a great wheel with either, but j-bend is a lot easier to work with and offers more flexibility. 

One nice thing about straight pull is it's easy to replace broken spokes, no need to remove the cassette if it's a drive-side, and no fishing it through all the other spokes like a heads-out spoke on a j-bend build. That's nice with Specialized's Roval MTB wheels, cause they break spokes a lot, so it's easy to fix them.


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## dgaddis1 (Sep 27, 2008)

coachboyd said:


> Another good point t brought up by Dustin at Southern Wheelworks. He built up a straight pull hub with round spokes and said Never Again!!.
> 
> The spokes just spin and it's hard to keep them in place without pliers. Bladed spokes are not as bad.


Seriously. NEVER AGAIN. I even bought a tool that's supposed to hold them, I just ended up with a cramping hand, you have to squeeze stupid hard and even then the spokes still spin sometimes. I don't ever build a new wheel with straight pull hubs, but that wheel I was lacing a replacement rim onto a Roval wheel. See my previous post...


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## nhluhr (Sep 9, 2010)

As others have said, if you go straight-pull, save yourself a huge headache and get BLADED spokes and use the appropriate blade spoke holder to keep them from rotating during tensioning. CX-Ray or Aerolite if you are happy with thin spokes, Aero Comp if you want something thicker.

As for tangible benefits, yes, absolutely. They remove the #1 failure point of bicycle spokes - the elbow. However, in doing that, they also inherently decrease the flange spacing and therefore the wheel's lateral stiffness by a small amount.


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## Mike T. (Feb 3, 2004)

nhluhr said:


> straight-pull...............They remove the #1 failure point of bicycle spokes - the elbow.


I guess if a spoke is going to break, that's where it will be but I'll bet most of us that have built wheels for years can't remember the last spoke that broke on us. Hence my earlier comment - a solution looking for a problem.


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## nhluhr (Sep 9, 2010)

Mike T. said:


> I guess if a spoke is going to break, that's where it will be but I'll bet most of us that have built wheels for years can't remember the last spoke that broke on us. Hence my earlier comment - a solution looking for a problem.


That's the same questionable argument against spoke-prep or alpina ABS style nipples. Just because you CAN build a wheel that doesn't need the benefit doesn't mean you shouldn't also double-down on your approach to make it even more bombproof-reliable.


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## Mike T. (Feb 3, 2004)

nhluhr said:


> That's the same questionable argument against spoke-prep or alpina ABS style nipples. Just because you CAN build a wheel that doesn't need the benefit doesn't mean you shouldn't also double-down on your approach to make it even more bombproof-reliable.


So you're saying that if I haven't built a wheel badly enough for a nipple to unscrew then I still should glue them in place? That's awesome logic. Maybe then I could do crap builds and still look like an expert!


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## Jay Strongbow (May 8, 2010)

Mike T. said:


> I guess if a spoke is going to break, that's where it will be but *I'll bet most of us that have built wheels for years can't remember the last spoke that broke on us*. Hence my earlier comment - a solution looking for a problem.


It's not just about you and other people who have built wheels for years. You probably haven't built and used 16/20 wheels either.


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## nhluhr (Sep 9, 2010)

Mike T. said:


> So you're saying that if I haven't built a wheel badly enough for a nipple to unscrew then I still should glue them in place? That's awesome logic. Maybe then I could do crap builds and still look like an expert!


That is exactly the opposite of what I said. Your implication that adding best-practices somehow mandates being sloppy elsewhere makes me hope to god you don't work in any kind of industry that affects me.


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## Mike T. (Feb 3, 2004)

nhluhr said:


> That is exactly the opposite of what I said. Your implication that adding best-practices somehow mandates being sloppy elsewhere makes me hope to god you don't work in any kind of industry that affects me.


Ok then, I'm supposed to use a belt *and* suspenders to hold up my pants?


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## ergott (Feb 26, 2006)

DT's straight pull flange spacing is worse than their traditional flanged rear hub. It's a similar problem with all straight pull hubs. You need material all around the outer most spoke in order to make the spoke hole. A traditional flange has half the spokes on the outside of the flange improving the spacing. Average of the inner and outer spokes ends up being better.

On to the spoke. Straight pull spokes are not immune to breaking at the head. Not by a long shot. Just ask people like me that have to service wheels on a regular basis. If you were to look at the percentage of straight pull spokes that break at the head to the millions of j-bend spokes Js are the winner.

So to wrap things up. Straight pull spokes aren't less prone to breaking and the hubs aren't better designed. The final nail in their coffin for me is the fact that it's almost impossible to use round spokes with them.

No thanks.


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## robt57 (Jul 23, 2011)

Mike T. said:


> Ok then, I'm supposed to use a belt *and* suspenders to hold up my pants?


Boy, I love this place. 

I didn't even know I was supposed to be wearing pants when I built wheels...


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## TiCoyote (Jun 28, 2005)

Straight pull look cooler. That should be the most important factor.


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## Mike T. (Feb 3, 2004)

robt57 said:


> I didn't even know I was supposed to be wearing pants when I built wheels...


You should. Cheezies might be harmless but don't get that anti-seize anywhere it shouldn't be.


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## rruff (Feb 28, 2006)

changingleaf said:


> From the measurements that I've taken straight pull hubs do not necessarily have a better bracing angle then j-bend designed hubs.


Straight pull is definitely not better in that respect, and most designs are worse.


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## rruff (Feb 28, 2006)

dcgriz said:


> It seems to me that the case of the straight pull spokes was created by the majors to address issues resulting from the quest of continuously attempting to reduce the number of spokes.


Not seeing any reason for it there. 



> Issues like loss of lateral stiffness (hubs with straight pulls tend to have better bracing angles than j-bend hubs)


What hub are you thinking of? It's possible, but usually the way the hub is made reduces the potential DS offset.



> spokes made from other material other than steel (beefy bladed aluminum spokes used by Mavic, Fulcrum, etc).


I think you are getting warm. Manufacturers want their products to look different. Branding and marketing.


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## dcgriz (Feb 13, 2011)

rruff said:


> What hub are you thinking of? It's possible, but usually the way the hub is made reduces the potential DS offset.
> .


When I compared the flange spacing of the Mavic Ksyrium SL to the j bend Durace I measured about 3 mm more on the Mavic, as I recall.
(Approximate numbers; I don't have the Mavics where I am now)


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## ergott (Feb 26, 2006)

To fairly measure a SP hub you have to take the average of the inner and outer spokes on each side. That's the equivalent of the j-bend spokes that have their elbows of both sides of the flange making the center to center of flange measurement an average of the two.


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## ergott (Feb 26, 2006)

A straight pull hub will always require material to surround the head of the spoke limiting clearance with the cassette. If you really wanted the best bracing angle it would be with all j-bend spokes oriented with the elbows on the outside of the flange. With low spoke count and a slightly paired grouping at the flange (not necessarily the rim) you could do theoretical two cross pattern for great torque transmission and all the elbows out.

It one aspect that I like about this hub from Rolf. The rest of the design, meh.


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## dcgriz (Feb 13, 2011)

Eric, the Mavic example I referred has the radial arrangement on the DS which makes the flange very thin compared to the typical straight pull staggered arrangement.
Their NDS arrangement is also thinner than the typical straight pull staggered arrangement; it seems that is how they are able to stretch out their flange spacing.

Not arguing the merits of this wheel; we all know the pros and the cons of the Mavics. Merely saying that straight pulls seem to have a place in certain applications


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## SwiftSolo (Jun 7, 2008)

In practice, I have a set of Enves disc wheels and a set of Bontragers Aeolus disc wheels, both with DT Swiss made hubs. The Enves are the traditional flange and the Aeolus are straight put. All of the straight pull spokes have a base width (both front and rear) as wide as the outside width of the traditional flange. Half of the spokes on the traditional have a base 1/4" narrower than any of the straight pulls. 

It was visually apparent the minute I opened the box of the Aeolus' that the spokes had a wider base.


ergott said:


> DT's straight pull flange spacing is worse than their traditional flanged rear hub. It's a similar problem with all straight pull hubs. You need material all around the outer most spoke in order to make the spoke hole. A traditional flange has half the spokes on the outside of the flange improving the spacing. Average of the inner and outer spokes ends up being better.
> 
> On to the spoke. Straight pull spokes are not immune to breaking at the head. Not by a long shot. Just ask people like me that have to service wheels on a regular basis. If you were to look at the percentage of straight pull spokes that break at the head to the millions of j-bend spokes Js are the winner.
> 
> ...


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## rruff (Feb 28, 2006)

ergott said:


> A straight pull hub will always require material to surround the head of the spoke limiting clearance with the cassette.


Yes. Something like this, is probably as good as it gets with SP unless you do radial on the DS. And you can always make a JB hub better. 











But... ultimately what causes clearance problems is the derailleur vs the spokes.


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## dracula (Mar 9, 2010)

Mike T. said:


> Of course you're going to get opinions. IMO they're a solution looking for a problem. I can't remember a bend in a spoke causing me a problem ever since I figured out how to build wheels properly (which would be about 20 years ago after 30 years of building them not properly).


One day I will build my own wheels.

Just out of curiosity: Did you learn wheel building based on ideas and techniques of Jobst Brandt's book 'The Bicycle Wheel'? 

Jobst was an avid poster on rec.bicycles.tech and despised everything carbon and especially low spoke count boutique wheels.

Edit: I answered my own question after following your link in your avatar. An interesting site - was not aware it exists.


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## dracula (Mar 9, 2010)

coachboyd said:


> I had asked this question to a bunch of wheel builders off forum as we are developing some mtb hubs. Every single one said jbend due to the flexibility.
> 
> Another good point t brought up by Dustin at Southern Wheelworks. He built up a straight pull hub with round spokes and said Never Again!!.
> 
> The spokes just spin and it's hard to keep them in place without pliers. Bladed spokes are not as bad.



I was wondering if it is easier to handle spoke twist with bladed spokes when building a wheel. A bladed twisted spoke is obvious but might not by using round spokes.


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