Thursday, 17 January 2013

The Twisted Truth: Leg Twist

Superfuture reader maxbit posted the following questionI just bought my first pair of vintage Levi's 501 jeans. They fit perfectly, with one caveat: The jeans seam twists on one side. So much so that the side sam is in the front at the bottom of the right side. I'm just curious what causes this and more importantly, are there any fixes?



Although maxit doesn't like the look, many do. 
AS the look of vintage jeans has become more prized, so has the phenomenon of leg twist - a property of older twill fabrics that was originally seen as a drawback or irritation. 

Pre -70s jeans suffer from Leg Twist, to differing degrees. Leg Twist is simply a natural adjustment of the fabric, which tends to follow the direction of the weave as the fabric moves or shrinks after washing. Stefano Aldighieri, who was Director of Fabric & Finishing at LS&Co. explains it thus: “Levi’s denim were mostly right hand twills; the twill line rises to the right. During the weaving process you basically ‘force’ the fabric to be straight, perpendicular to the selvage, but at the same time you give it this direction in the construction. You lay and cut the fabric; in the early days LS&Co. patterns were cut straight along the selvage. When you wash the garments, the fabric will try to follow the direction of the weave and will pull in that direction.... hence the twisted legs, the result of the movement of the fabric. Because Lee started to use left hand weave denims, their legs would twist the other way.” 

As Stefano points out, Leg Twist is much more noticeable on jeans than on other fabrics because of the construction, with the selvage edge used on the outseam. 

Leg Twist was eliminated in the 1970s by skewing (which contorts denim to its after-wash shape) - and later revived with Levi’s Red and Engineered twisted seams jeans!

What's intriguing abut Leg Twist is that is seems to vary so much between different examples of vintage jeans. I've seen it more often on early 1970s Levi's - although, of course, I've worn more original '70s Levi's and, sadly, only one original pair of '50s. Some vintage jeans have marginal leg twist, but on the odd example, you can have the seam on the left leg rotate so it's almost on the front of the jean. So what are the variables that would cause leg twist, some but not all of the time? I asked Ralph Tharpe, who oversaw the development of many of Cone's finest fabrics and now oversees the Artistic Fabric Mills in the US, what causes so much variation in leg twist. 

"That's a good question. I think partly it has to do with the type of seam that's sewn on the inside. I think the way the jean is sewn when the operator is sewing the jean, when she sews up the right leg and down the left, if she's pulling too hard coming down the left, then she's accentuating what the fabric want to do and making the skew worse. It can be really, really bad. 

"I also have another theory, which I've never been able to prove. When I started working at White Oak I was in the quality area, and we were grading loomstate denm. They had a defect they call long sides. Long sided means one side of the denim was stretching out or was longer than the other. Maybe this was something wrong with the loom, maybe the crank arms weren't adjusted exactly the same on both sides, so the pick is going in slightly at an angle. If that were the case, and again this is totally theory, than if that were the case the skew the fabric wants to move to would be really accentuated. On the other hand, if the pick is in the opposite direction it would be reducing the skew. Anyway - it's just a theory."

So, leg twist is a product both of fabric movement, and the garment construction. 

I didn't ask Ralph whether it's possible to alter jeans after they're sewn to eliminate the leg twist as, in practical terms, it's impossible. You just have to live with it, taking comfort from the fact it's a mark of cool, old jeans. 

When my LVC '47, both pairs, started showing heavy leg twist  after their first wash, I was pleased. But plenty of people will comment that I'm twisted already.





14 comments:

  1. LVC 47's were my first pair of selvage denim, and I actually had no idea leg twist was even a thing. I noticed it and thought my jeans were screwed up. Since researching it, I now consider it to be a (small) badge of honor. I have more leg twist in my Levi's 47's than I do in my loomstate ROY RS04, although the ROY's do have a touch of it. I like it.
    -GG in S

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  2. I've never been a fan of the effect but it's nevertheless interesting to hear the reasons why it happens and theories

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  3. Actually both theory are right. the twisting legs comes from two factor 1) Weaving 2) Sewing
    But the twisting result will be different. When the twisting is one direction like on your picture this come from the weaving. when both leg twisting on opposite direction it come from the sewing. Sadly this cannot be fixed. Nice worn effect by the way .

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    1. So if one leg twists and not the other, then am I correct in assuming that its the sewing technique being used? Will adjusting the grain line on the fabric help at all to prevent twisting?

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  4. I have the same jeans as above and love the fact the twist.

    Bluebell mills developed broken twill to counteract the twisting effect. Wrangler being the most obvious brand who used this denim.

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    1. The twisted legs can happen for two reasons only :
      1) if the sanforized fabric has a wrong / high movement (means that skew before wash - skew after wash gives a difference of more than 3 %).

      2) the cutting plan is wrong (means that the axiz of each panel is not perfectly paralell with the warp threads, specially the panels that will be stitched into legs)

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    2. Thanks anonymous. Here we're discussing non-sanforized jean, on which there will be some leg twist, even with perfect cutting and sewing.

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    3. Good call Anonymous at 03:29. I worked in a denim mill throughout high school and college making both Levi's 4:1 right hand twill denim and broken twill Blue Bell denim. The reason we were always given for Blue Bell wanting broken twill was to prevent leg twist. The trade-off is that it isn't quite as durable.

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  5. When making up a pair of trousers (of any material), the novice is trained to ensure that the knees and hips are perfectly aligned, to prevent twisting of the legs. If the notches indicating the level of the knees and hips are not properly aligned when making up on the sewing machine, the side seams will twist over time. With relatively low manufacturing standards in earlier jeans, and the tendency of sewing machines to "full on" one of the pieces of fabric, alignment problems and resultant twisting is a common issue. I suspect that what Levis managed to achieve in the 70s was increased quality control, rather than any great revolution in cutting.

    I've noticed, btw, an ever increasing twist in my LVC 1933 501s. With each wash the twist becomes more pronounced.

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  6. When making up a pair of trousers (of any material), the novice is trained to avoid twisting of the legs. This is achieved by aligning the knees and hips perfectly when making up, and fighting the "fulling on" tendencies of the sewing machine. When the knees and hips are not properly aligned, the leg seams will twist. The twisting of earlier jeans is most likely to be due to poor quality control. It seems likely that increased quality control was the fix Levis effected in the 70s, rather than any great revolution in cutting or weaving.

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  8. Interesting point, anonymous. Improved quality control might have been a factor, but the reason for the elimination of leg-skew in the late 70s was the introduction of preskewing.
    Leg twist happens in all 50s and 60s Levi's jeans - what Ralph believes, as do I, is that sewing can affect the amount of the skew.

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  9. I recently bought a pair of skinny fitting jeans which have a really bad torque on the left leg only. The inseam twists all the way to the front of my ankle. Is this due to sewing or weaving? Is this something I can complain to the manufacturer about? The right leg is fine.

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  10. A strange phenomenon... the twisted jeans by Levis. I work at Value Village and have seen these come in to the store and they looked quite odd to me, but I have been drawn to them as all my cool jeans twist and was curious with these as they have the added hem on them that just seemed right. They are shorter towards the inside ankle and a tad longer on the outside ankle. Now I am an old school 56 year old female. When you hold them up on the hanger they really look like a pair of jeans for a bull legged cowboy. But upon trying a pair on I was instantly thinking these are just right!!! Levis seemed to do it right and these jeans are made extremely well made. There are no labels to say what cut they are so all I can say if you are looking for a pair hold them up and if they look weird try them on!

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