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For bedding in spokes and stress relieving the wheel I use my hands. To try and prevent calluses as much as possible I use heavy duty gardening gloves, though I still get sore hands after doing a few wheels one after the other. I never take the wheel out of the stand to stress it laterally as I think it wastes time and can potentially damage light weight rims.
Another important point to bear in mind is that there are two end processes involved in using your hands and, essentially, grabbing fistfuls of spokes is to deal with any residual spoke twist and to equalise inbuilt stresses in the spokes. As Jobst Brandt says (though he sees only one true end product from the stress relieving procedure, "bedding in the spokes" does not come into it):http://sheldonbrown.com/brandt/stress-relieving.html
It appears that the process of stress-relieving is obscure to many if not most people, because after seeming to have made it clear, comments still surface. Spokes are cold formed from wire that is (at least DT) as hard and work hardened as it can become. Tensioning does not further harden spokes, there being no plastic deformation. Besides, wire ductility is important both in forming spokes and in use.
The coiled wire from which spokes are made is straightened by running it first between rollers staggered in X and then in Y, the wire moving in the Z direction. Reverse bending acts as a degausser, having ever diminishing excursions that affect ever shallower depths of the wire. This stress-relieves the wire while removing the curl of being shipped in a coil. If it had no curl, releasing its free end on the spool would allow it to uncoil explosively into a huge bird's nest.
Wire is cut into suitable lengths, the first operation being to cold-form a spoke head onto one end with one axial blow of a die, after which the spoke is cut to a specific length before rolling the thread and bending a 100-degree elbow.
Threads, head, and elbow contain metal that was plastically deformed (beyond yield) as well as metal that was elastically deformed, each having elastic memory. In these transitions, parts that yielded and ones that did not are in conflict, each wanting to return to or stay in a different shape. This is why a spoke bent by hand springs back only partially when released.
On lacing spokes into a wheel, elbows are often additionally bent (brought to yield), thus remaining at or exceeding yield stress during tensioning. Threads also have internal tensile stress besides local compressive stress at the threads. The thread core is already in tension from the lengthening effect of thread rolling, and its stress only increases with tensioning.
Therefore, spokes in a newly built wheel have locations where stress is near yield, some more so than others. Because fatigue endurance of a metal at or near the yield stress is short, cyclic loads in such spokes will cause failures at high- stress points. In normal use, a wheel only unloads spokes, but with spokes near yield, even these stress cycles readily cause fatigue failures. Only the lightest riders on smooth roads might be spared failures with a wheel whose spokes have not been stress-relieved.
Stress relieving to relax these high stress points is accomplished by over-stressing them in order to erase their memory. It is not done to bed the spokes into the hub, as is often stated. Bedding-in occurs sufficiently from tension. However, stretching spoke pairs with a strong grasp at mid-span, can momentarily increased tension by 50% to 100%. Because spokes are usually tensioned no higher than 1/3 their yield stress, this operation has no effect on the spoke as a whole, affecting only the small high stress zones where spokes are near yield. By stretching them, these zones relax below yield by as much as the overload.Stress relieving with a light grasp of spoke pairs is worthless, as is bouncing the wheel or bending it in a partially opened drawer. Pressing axially on the hub, while supporting the rim, requires a force larger than is manually possible but is effective for spoking machines (except the left side rear spokes that would collapse the rim). Another not recommend method, is laying the wheel on the floor and walking on it with tennis shoes, carefully stepping on each pair of crossed spokes. The method works but bends the rim and is difficult to control.
It is STRESS RELIEVING! Even though people insist on calling it pre-stressing or seating-in. The wheel is already prestressed when tensioned.
As has been mentioned in this thread just very recently a number of times the method of overturning the spoke nipple then backing it off deals very effectively with residual spoke twist, this is a method Brandt himself endorsed, therefore grabbing handfuls of spokes during the stress relieving process should be unnecessary but at least if you don't hear the tell-tale "ping!" you know you've done your job right.
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Cool I guess but front isn't exactly special in terms of weight, 3g lighter than my £20 eBay job.
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51g
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Those enve hubs are like £1000 a pair or something crazy.
Yes, but they're ½oz lighter than £300 Tune Mig70/Mag170 combination, you can't put a price on that.
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Extralite hubs weigh in at 182g for pair. They are apparently fairly reliable too in terms of bearing life. Those enve hubs look a bit to pricey. For that money (actually less as I got them trade) I had cliff at Royce make me some titanium flanged hubs with a carbon shell. The rear hub is for 2:1 lacing and has a flange seperation of 63 mm. Surely if you are going to spend that much on hubs you want them to look like jewelry, last a lifetime and be well unique.
The wheels that I built them into are simply lovely.
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Grasping pairs of spokes does permantly stretch the spokes contary to what sheldon suggests. I can show this as when i build a wheel and fully stress relive i see a tension drop which is quite significant. With laser I see a 200 to 300 newton tension drop when I really go at it. If the rim is faulty which annoying and I rebuild or worse I built with he wrong colour rim then I find further grasping of spokes does not cause a tension drop. So spokes do stretch when building. Sheldon is wrong for once unless some one has another explanation for what I see.
I now stress relieve throughout the build as I find it easier as the tension drop each time is jot big and more easily corrected. Also you can ensure that each spoke has been uniformly stressed.
Never damaged a rim when loading it while the hub axle is on the bench. It only works however with stiff wheels. If the wheel is not stiff like a rigid a chain a build then all that happens is the nds spoke unload and the wheel goes out of true every time and you get nowhere. If find side loading is the best way to deal with wind up and grasping pairs of spokes ensures there is no tension drop once the wheel is ridden.
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I feel your pain. I bought a spiffy new 24h Tune rear hub for my Zipp 404 Firecrest rear wheel. Then I discovered the rim is 20h. Such is life, and yes, @ugosantalucia was right after all. Still, it means the 24h/20h Flo30 rims I bought on a whim are getting Tune hubs...
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I got some wheels of eBay for the alloy axle chorus hubs. Turns out the hubs are perfect and the fir tubular rims they are laced to are perfect. The wheel needs truing and tensioning up properly but what a result. Sometimes fleabay is o.k. £70 is not bad for this got quite lucky I think.
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This is how an I9 straight-pull hub is supposed to work:
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Unless I missed some exotic advantage
I don't think there's any actual advantage, but threading the spokes into the hubshell isn't a terrible idea.
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Well, it means two ends to thread, two ends to keep an eye on, for... ???
OK you get a straight line, instead of elbows which can create stress points, but it's not that hubs are exploding left/right/center.
TL:DR I don't get it and it seems to violate the "If it ain't broken" and "KISS" principles ^_^
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Wheelbuilding / Wheel Building / Wheel build help
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For circular cross section spokes I use a paper clip in the middle of whatever spoke I'm tensioning, pointing inline with the braking surface of the rim. As I tighten the nipple, say 1/4 turn, I keep an eye on the paperclip and add more to the turn based on how much the paperclip moves with the spoke. After I'm finished with 1/4 I wind the nipple back to bring the paper clip back into line with the rim.