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#1
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Cross 3 or 4
I am threading a new wheel, and have a set of good spokes I can
recycle from another rim. It turns out that if I use cross 4, I can use the old spokes (which are quite expensive strong Swiss ones). The hub is a spoke eater Torpedo hub. So my question is, is there a difference in the strain on the spokes between 3- and 4-cross? I do have small washers at the spoke "elbows" which seems to work, but I'd like to know whether there is difference anyway. -- Dieter Britz (dieterhansbritzatgmail.com) |
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#2
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Cross 3 or 4
On Jul 25, 10:23*am, Dieter Britz wrote:
I am threading a new wheel, and have a set of good spokes I can recycle from another rim. It turns out that if I use cross 4, I can use the old spokes (which are quite expensive strong Swiss ones). The hub is a spoke eater Torpedo hub. So my question is, is there a difference in the strain on the spokes between 3- and 4-cross? I do have small washers at the spoke "elbows" which seems to work, but I'd like to know whether there is difference anyway. What appears to me to be most important is the angle the spokes leaving the inside of the flange show to the flange. The angle should be as low as you can get it to prevent failure of the inner spokes at their elbows. With the typical small hub flange this means that a cross 3 is preferred on a 36 spoke wheel. A cross 4 moves the angle so that it benefits (in preventing elbow fatigue) from double tied and soldered. Getting the crossing nearest the rim, nearer to the rim using more crossings or a wider flange will result in a wheel with more accurate tracking as will tying and soldering. The small washers are used under the spoke heads to pull the elbows tight against the flange. The use of punches to set the heads and elbows is prefered to eliminate the need for both settling in and overstressing the spokes in an attempt to better the wheel. |
#3
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Cross 3 or 4
In article ,
Dieter Britz wrote: I am threading a new wheel, and have a set of good spokes I can recycle from another rim. It turns out that if I use cross 4, I can use the old spokes (which are quite expensive strong Swiss ones). The hub is a spoke eater Torpedo hub. So my question is, is there a difference in the strain on the spokes between 3- and 4-cross? The purpose of crossed lacing is to get the stress on the hub flange drillings to be near tangential. The answer to your question is yes, but you need not concern yourself with the difference. After lacing the spokes, and before bringing them up to working tension, you should shape the spokes near the elbow so that the spokes aim toward the rim drillings. This reduces the built in strains near the elbows. Usually we reuse spokes only in the same hub when changing the rim. I do have small washers at the spoke "elbows" which seems to work, but I'd like to know whether there is difference anyway. -- Michael Press |
#4
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Cross 3 or 4
Dieter Britz wrote:
I am threading a new wheel, and have a set of good spokes I can recycle from another rim. It turns out that if I use cross 4, I can use the old spokes (which are quite expensive strong Swiss ones). The hub is a spoke eater Torpedo hub. So my question is, is there a difference in the strain on the spokes between 3- and 4-cross? I do have small washers at the spoke "elbows" which seems to work, but I'd like to know whether there is difference anyway. I you have spokes for cross-4 lacing, use them. Cross-4 on 32 spoke wheels is past tangential, and makes no sense. Cross-4 on 48 spoke wheels is the same as cross-3 on 36 spoke wheels: a sensible and uncomplicated pattern that puts minimal stress on the hub flange. But cross-4 on 36 spoke wheels is the closest to purely tangential lacing you can get with that spoke count. On a low-flange hub, the spokes can overlap adjacent spokes' heads, making repairs of broken spokes a bit more complicated than necessary. And if the hub flange is large or the rim is small, spokes can enter the rim at a too-sharp angle. But there are no other drawbacks to it. Chalo |
#5
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Cross 3 or 4
Michael Press wrote:
In article , Dieter Britz wrote: I am threading a new wheel, and have a set of good spokes I can recycle from another rim. It turns out that if I use cross 4, I can use the old spokes (which are quite expensive strong Swiss ones). The hub is a spoke eater Torpedo hub. So my question is, is there a difference in the strain on the spokes between 3- and 4-cross? The purpose of crossed lacing is to get the stress on the hub flange drillings to be near tangential. The answer to your question is yes, but you need not concern yourself with the difference. After lacing the spokes, and before bringing them up to working tension, you should shape the spokes near the elbow so that the spokes aim toward the rim drillings. This reduces the built in strains near the elbows. Usually we reuse spokes only in the same hub when changing the rim. How do I "shape the spokes"? When I have laced them all, they are more or less at their final angles with respect to the rim where they enter the rim. How can that be changed? Am I correct in assuming that the ideal is that the spoke enters the rim at right angles to the rim tangent, and close to tangent to the hub flange? I suppose a real wheel must make a compromise between the two. The reason I am doing this is that on a rim I have, one spoke has almost pulled itself through the rim hole and will come out any day now. And, the only reason I am considering the 4x pattern is that then, I can reuse the spokes I have, and would save me the money for new, shorter, ones. -- Dieter Britz (dieterhansbritzatgmail.com) |
#6
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Cross 3 or 4
On Jul 26, 7:26*am, Chalo wrote:
Dieter Britz wrote: I am threading a new wheel, and have a set of good spokes I can recycle from another rim. It turns out that if I use cross 4, I can use the old spokes (which are quite expensive strong Swiss ones). The hub is a spoke eater Torpedo hub. So my question is, is there a difference in the strain on the spokes between 3- and 4-cross? I do have small washers at the spoke "elbows" which seems to work, but I'd like to know whether there is difference anyway. I you have spokes for cross-4 lacing, use them. Cross-4 on 32 spoke wheels is past tangential, and makes no sense. Cross-4 on 48 spoke wheels is the same as cross-3 on 36 spoke wheels: a sensible and uncomplicated pattern that puts minimal stress on the hub flange. But cross-4 on 36 spoke wheels is the closest to purely tangential lacing you can get with that spoke count. * But it is a poor choice (unless tied and soldered) when the hub is offset due to the larger declination angle it forms to the hub flange. This will tend to overly strain the spoke elbow and head, particulary if setting tools are avoided, and so will lead to a less than extensive lifespan. On a low-flange hub, the spokes can overlap adjacent spokes' heads, making repairs of broken spokes a bit more complicated than necessary. *And if the hub flange is large or the rim is small, spokes can enter the rim at a too-sharp angle. *But there are no other drawbacks to it. Chalo |
#7
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Cross 3 or 4
On Jul 26, 9:31*am, Dieter Britz wrote:
Michael Press wrote: In article , *Dieter Britz wrote: I am threading a new wheel, and have a set of good spokes I can recycle from another rim. It turns out that if I use cross 4, I can use the old spokes (which are quite expensive strong Swiss ones). The hub is a spoke eater Torpedo hub. So my question is, is there a difference in the strain on the spokes between 3- and 4-cross? The purpose of crossed lacing is to get the stress on the hub flange drillings to be near tangential. The answer to your question is yes, but you need not concern yourself with the difference. After lacing the spokes, and before bringing them up to working tension, you should shape the spokes near the elbow so that the spokes aim toward the rim drillings. This reduces the built in strains near the elbows. Usually we reuse spokes only in the same hub when changing the rim. How do I "shape the spokes"? When I have laced them all, they are more or less at their final angles with respect to the rim where they enter the rim. How can that be changed? Use an 8" long starting punch with a 3/16" hollow ground tip and a hammer. A nail set may do but they don't generally have the reach required for comfortable use. First strike in the heads then strike in the elbows. Two small flat cone spanners used around the interleaved crossing may be used to correct the spoke line there. Don't mess with the spokes near to the rim. If it appears they have not seated with the spokes leading straight to the crossing (use a straight edge with a lowered spoke tension) then the rim's spoke seating requires adjustment. A punch with a flat or convexed point is most appropriate. Sometimes though it is just a case of elongating the eyelet a little using a tapered punch which fits through it. Am I correct in assuming that the ideal is that the spoke enters the rim at right angles to the rim tangent, and close to tangent to the hub flange? The two are mutually exclusive unless some additional wiring is performed pulling the near to parallel spokes together halfway between their bindings at the interlace and the rim. It's additional work which I doubt will reap any requsite practical rewards. I suppose a real wheel must make a compromise between the two. The reason I am doing this is that on a rim I have, one spoke has almost pulled itself through the rim hole and will come out any day now. Use less spoke tension. And, the only reason I am considering the 4x pattern is that then, I can reuse the spokes I have, and would save me the money for new, shorter, ones. Well just do it. I ran a 32 spoke with cross 4 lacing a number of years because I had the spokes. You have to be careful in setting the spoke heads, which becomes essential on the outside of the flange due to the outer spokes then bearing on the adjacent spoke's head. You may also wish to create a slight bend here in the outer spokes to minimise their bending strains in use. There was never any practical problems with me running a 32 spoke rear wheel with cross 4 spoking, but after 4 years I decided I needed to rectify the "error". I'd actually had no problems with my bike apart from a slightly soft rear wheel playing up in the corners and really just needed something to do and new spokes and rear derailleur was that something. At that time I failed to really address the issue of the wheel's laterally soft response but phsychologically there was an improvement. |
#8
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Cross 3 or 4
On Jul 26, 1:26*am, Chalo wrote:
Dieter Britz wrote: I am threading a new wheel, and have a set of good spokes I can recycle from another rim. It turns out that if I use cross 4, I can use the old spokes (which are quite expensive strong Swiss ones). The hub is a spoke eater Torpedo hub. So my question is, is there a difference in the strain on the spokes between 3- and 4-cross? I do have small washers at the spoke "elbows" which seems to work, but I'd like to know whether there is difference anyway. I you have spokes for cross-4 lacing, use them. Cross-4 on 32 spoke wheels is past tangential, and makes no sense. Cross-4 on 48 spoke wheels is the same as cross-3 on 36 spoke wheels: a sensible and uncomplicated pattern that puts minimal stress on the hub flange. But cross-4 on 36 spoke wheels is the closest to purely tangential lacing you can get with that spoke count. *On a low-flange hub, the spokes can overlap adjacent spokes' heads, making repairs of broken spokes a bit more complicated than necessary. *And if the hub flange is large or the rim is small, spokes can enter the rim at a too-sharp angle. *But there are no other drawbacks to it. Chalo Yup. I've done a x4 on a small flange with that very result. Hopefully the guy I sold the bike to won't ever brake a spoke... |
#9
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Cross 3 or 4
In article ,
Dieter Britz wrote: Michael Press wrote: In article , Dieter Britz wrote: I am threading a new wheel, and have a set of good spokes I can recycle from another rim. It turns out that if I use cross 4, I can use the old spokes (which are quite expensive strong Swiss ones). The hub is a spoke eater Torpedo hub. So my question is, is there a difference in the strain on the spokes between 3- and 4-cross? The purpose of crossed lacing is to get the stress on the hub flange drillings to be near tangential. The answer to your question is yes, but you need not concern yourself with the difference. After lacing the spokes, and before bringing them up to working tension, you should shape the spokes near the elbow so that the spokes aim toward the rim drillings. This reduces the built in strains near the elbows. Usually we reuse spokes only in the same hub when changing the rim. How do I "shape the spokes"? When I have laced them all, they are more or less at their final angles with respect to the rim where they enter the rim. How can that be changed? If the spokes aim at the rim in a laced and un-tensioned wheel, then everything is fine. If the spokes bow out at the hub, a bit of thumb pressure on the spoke at the hub flange will bend the spoke enough to get it aimed at the rim. Am I correct in assuming that the ideal is that the spoke enters the rim at right angles to the rim tangent, and close to tangent to the hub flange? Yes. Sometimes a spoke needs a bit of correction at the nipple end to make the nipple seat at a right angle even though the spoke is not at a right angle. These adjustments are to reduce built in stress in the spoke. I suppose a real wheel must make a compromise between the two. The reason I am doing this is that on a rim I have, one spoke has almost pulled itself through the rim hole and will come out any day now. And, the only reason I am considering the 4x pattern is that then, I can reuse the spokes I have, and would save me the money for new, shorter, ones. Okay. Good luck. -- Michael Press |
#10
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Cross 3 or 4
Chalo wrote:
But cross-4 on 36 spoke wheels is the closest to purely tangential lacing you can get with that spoke count. On a low-flange hub, the spokes can overlap adjacent spokes' heads, making repairs of broken spokes a bit more complicated than necessary. And if the hub flange is large or the rim is small, spokes can enter the rim at a too-sharp angle. But there are no other drawbacks to it. I think you've just convinced me to bite the bullet, get a set of shorter spokes and thread them with 3x. This is because not only do I have spoke heads, but these washers under the head, to prevent spokes breaking. They must interfere with adjacent spokes more than the heads themselves. Thanks everybody for your input. "Everything is illuminated". -- Dieter Britz (dieterhansbritzatgmail.com) |
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