I’ve always been especially fond of spiral motifs, and this heel design was in my head long before I figured out how to do it. There are two main techniques you’ll learn in doing this pattern:
• 4-strand helix heel with no ends to weave in where you cast on
• basic heel-out sock construction.

There are many different ways to wrap a helix around a foot, and this pattern shows but one interpretation designed specifically for high-contrast, semisolid yarns. Additional interpretations are available on my blog.

Heel-out sock construction lends itself nicely to variations as well. Since it doesn’t matter whether the foot is worked before or after the cuff, I did the foot first in sock #1, and the cuff first in sock #2, resulting in a positive/negative effect.

Several acknowledgements are warranted here. Thanks to sarah-marie belcastro for her various spiral and helix projects posted on Ravelry, and to Kathleen Sperling for publishing the Hat Heel Sock. These inspirations provoked a flurry of ideas for alternative sock constructions featuring spiral motifs. Also, thanks to my friend Leila Wice for coming up with the name “Heelix.”

SIZE
Women’s S (M, L)
To determine your size, measure diagonally around your heel and instep as shown in the diagram below.

Small: 11.25-11.75 inches
Med: 11.75-12.25 inches
Large: 12.25-12.75 inches

FINISHED MEASUREMENTS
Length of foot: knit-to-fit.
Foot circumference: Sock is 7.5 (8, 8.5) inches unstretched.
Cuff circumference: Ribbing is about 6 inches unstretched; stretches comfortably to 14 inches.

MATERIALS
Yarn
[MC] Shibui Sock [100% superwash merino wool; 191yd/175m per 50g skein]; color: Peacock 323; 1 skein
[CC] Koigu [100% superwash merino wool; 175yd/160m per 50g skein]; color: 2339; 1 skein (Koigu is a very slightly larger gauge than Shibui, but the yarns go together nicely. FYI, Shibui also has a comparable colorway, Kiwi.)

Recommended needle size
[always use a needle size that gives you the gauge listed below -- every knitter's gauge is unique]
1 set US #1.5/2.5mm double-pointed needles
OR
1 long US #1.5/2.5mm circular needle for magic loop
OR
2 US #1.5/2.5mm circular needles for two-circulars

Notions
Yarn needle
Scrap yarn (similar weight to sock yarn), approx. 6 feet
Crochet hook (size comparable to 2.5 mm)

GAUGE

PATTERN NOTES
[Knitty's list of standard abbreviations and techniques can be found here.]

New! Jeny has provided a video of the cast on and first 2 cycles of Double Heelix. Watch it here.

What is Helix knitting?
In its simplest form, helix knitting is more common than most knitters realize. Mathematically speaking, knitting in the round with one strand of yarn can qualify as a helix. But in the knitting vernacular, “Helix knitting” typically refers to two or more strands.

Technically these are spirals, not helices, but you get the idea.

Featured techniques:

• Helix knitting
• Provisional cast on using a crochet chain
• Kitchener Stitch (grafting)
• Interlock Bindoff
• Judy's Magic Cast On (JMCO)
  
• Using JMCO to increase stitches
• Working wrapped stitches together with their wraps
  

Using Judy’s Magic Cast On to increase stitches
In helix knitting, whenever you have 2 working strands stacked on top of each other, you can use these strands to cast on stitches. This adaptation of JMCO is a critical component of this pattern.

Step 1: Immediately following the Double Heelix Cast On (see “Double Heelix Cast On” section under Pattern), your stitches should look like the illustration below. Take the top CC strand and cross it in front of the bottom strand (see arrow).

Note: For illustration purposes, 2 different colors are used for the top (yellow) & bottom (light green) strands of CC.

Step 2: Hold the strand from the bottom row of CC over your forefinger and the strand from the top row over your thumb. Bring the forefinger strand up in front of the bottom needle and behind the top needle.

Step 3: Bring the thumb strand up behind the bottom needle and in front of the top needle.

Your work should look like this:

Step 4: Swing your hand down behind the needles…

And voila! You’ve just cast on 1 stitch on each needle.

Repeat Steps 2-4 until you have cast on all the sts you need (Step 5 diagram shows 2 sts cast on each needle). Then:

Step 5: Holding both strands securely, pivot the needles clockwise around the cast on sts.

Your work should look like this:

Step 6: Hold the thumb strand behind the work and the forefinger strand above the work. If using cable needles, pull the cable through the bottom sts. Slip the first stitch purlwise.

Using the forefinger strand, knit the rest of the sts on the needle.

Throughout this pattern, you’ll do a JMCO increase every time you have 2 working strands of the same color on each side. Increasing sts with JMCO instead of traditional increases maintains a stronger visual continuity of the spiral.

Working Wrapped Stitch
To work a wrapped stitch together with its wrap on the knit side, knit to wrapped stitch. Slip next stitch from left needle to right needle, use tip of left needle to pick up "wrap" and place it on right needle, insert left needle into both wrap and stitch, and knit them together.

DIRECTIONS

Pull out a long tail from each ball of yarn, approximately 15 feet in length. Fold the yarn at this point – this is where you will cast on.

Double Heelix Cast On

Step 1: With MC, starting at the fold and on the bottom needle, JMCO 10 sts each needle.

Hold both strands and pivot work as illustrated in Step 5 of JMCO increase instructions above.

Step 2: With MC, sl1, k1; with CC, k8. Then slip 7 of the 8 sts you just knitted back to the left needle and knit them again with the other strand of CC.

At this point your work should look something like this:

Double Heelix Cast On

It will be a bit easier to explain if I use diagrams…

Note that for each color, there are two working strands at each end, yielding a total of 4 working strands.

On the first round (see Heel section, Cycle 1), you’ll knit the first half with CC and the second half with MC…

… yielding a result that looks something like this.

This is Configuration B, in which the two strands at each end are different colors.

On the following round (still Cycle 1), you’ll do this again…

… yielding a result that looks something like this.

This is Configuration A, in which the two strands at each end are the same color.

Get the idea? The strands keep chasing each other around in an interlocking spiral.

Heel
As you work the heel, you will cycle between Configurations A and B a total of 8 (9, 10) times, increasing sts using the JMCO increase as you go, until you have a total of 30 (32, 34) sts on each needle.

Each cycle is 2x around, starting and ending with Configuration A. Note that Cycle 1 is slightly different than all subsequent cycles.

Cycle 2
With MC, JMCO increase 2 sts each needle. 14/14 sts. Rotate.
With MC, sl 1, k13 to end. 1 MC strand will be stacked on top of 2 CC strands.
With CC, JMCO increase 2 sts each needle. 16/16 sts. Rotate.
With CC, sl 1, k 15 to end. Rotate. Configuration B, 2 contrasting sts (in CC) at end of one needle.
With MC, k14 to just before the 2 CC sts, then switch to bottom strand of MC.
K2, then sl these 2 back to L needle and k again with top strand of MC. Rotate.
With CC, k16 to end. Configuration A.

Cycle 3
With CC, JMCO increase 2 sts each needle. 18/18 sts. Rotate.
With CC, sl1, k17 to end.
With MC, JMCO increase 2 sts each needle. 20/20 sts. Rotate.
With MC, sl1, k19 to end. Rotate. Configuration B, 2 contrasting sts (in MC) at end of one needle.
With CC, k18 to just before the 2 MC sts, then switch to bottom strand of CC.
K2, then sl these 2 back to L needle and k again with top strand of CC. Rotate.
With MC, k20 to end. Configuration A.

Heel shaping: Up to now you have been casting on 2 JMCO sts at a time on each needle (adding 4 sts on each end). For the rest of the heel, you will cast on 1 JMCO st on each needle (adding 2 sts on each end), thereby shifting to a more gradual angle. This shaping will make your heel more rounded and less trapezoidal.

Cycle 4
With MC, JMCO increase 1 st each needle. 21/21 sts. Rotate.
With MC, sl1, k20 to end.
With CC, JMCO increase 1 st each needle. 22/22 sts. Rotate.
With CC, sl 1, k21 to end. Rotate. Configuration B, 1 contrasting st (in CC) at end of one needle.
With MC, k21 to just before the 1 CC st, then switch to bottom strand of MC.
K1, then sl this st back to L needle and k again with top strand of MC. Rotate.
With CC, k22 to end. Configuration A.

Cycle 5
With CC, JMCO increase 1 st each needle. 23/23 sts. Rotate.
With CC, sl1, k22 to end.
With MC, JMCO increase 1 st each needle. 24/24 sts. Rotate.
With MC, sl1, k23 to end. Rotate. Configuration B, 1 contrasting st (in MC) at end of one needle.
With CC, k23 to just before the 1 MC st, then switch to bottom strand of CC.
K1, then sl this st back to L needle and k again with top strand of CC. Rotate.
With MC, k24 to end. Configuration A.

Cycle 6
With MC, JMCO increase 1 st each needle. 25/25 sts. Rotate.
With MC, sl 1, k24 to end.
With CC, JMCO increase 1 st each needle. 26/26 sts. Rotate.
With CC, sl 1, k25 to end. Rotate. Configuration B, 1 contrasting st (in CC) at end of one needle.
With MC, k25 to just before the 1 CC st, then switch to bottom strand of MC.
K1, then sl this st back to L needle and k again with top strand of MC. Rotate.
With CC, k26 to end. Configuration A.

Cycle 7
With CC, JMCO increase 1 st each needle. 27/27 sts. Rotate.
With CC, sl1, k26 to end.
With MC, JMCO increase 1 st each needle. 28/28 sts. Rotate.
With MC, sl1, k27 to end. Rotate. Configuration B, 1 contrasting st (in MC) at end of one needle.
With CC, k27 to just before the 1 MC st, then switch to bottom strand of CC.
K1, then sl this st back to L needle and k again with top strand of CC. Rotate.
With MC, k28 to end. Configuration A.

Cycle 8
With MC, JMCO increase 1 st each needle. 29/29 sts. Rotate.
With MC, sl1, k28 to end.
With CC, JMCO increase 1 st each needle. 30/30 sts. Rotate.
With CC, sl1, k29 to end. Rotate. Configuration B, 1 contrasting st (in CC) at end of one needle.
With MC, k29 to just before the 1 CC st, then switch to bottom strand of MC.
K1, then sl this st back to L needle and k again with top strand of MC. Rotate.
With CC, k30 to end. Configuration A.

STOP HERE if making size S.

Cycle 9
With CC, JMCO increase 1 st each needle. 31/31 sts. Rotate.
With CC, sl1, k30 to end.
With MC, JMCO increase 1 st each needle. 32/32 sts. Rotate.
With MC, sl1, k31 to end. Rotate. Configuration B, 1 contrasting st (in MC) at far end.
With CC, k31 to just before the 1 MC st, then switch to bottom strand of CC.
K1, then sl this st back to L needle and k again with top strand of CC. Rotate.
With MC, k32 to end. Configuration A.

STOP HERE if making size M.

Cycle 10
With MC, JMCO increase 1 st each needle. 33/33 sts. Rotate.
With MC, sl1, k32 to end.
With CC, JMCO increase 1 st each needle. 34/34 sts. Rotate.
With CC, sl1, k33 to end. Rotate. Configuration B, 1 contrasting st (in CC) at end of one needle.
With MC, k33 to just before the 1 CC st, then switch to bottom strand of MC.
K1, then sl this st back to L needle and k again with top strand of MC. Rotate.
With CC, k34 to end. Configuration A.

Status check: You should have 30[32, 34] sts on both needles, for a total of 60[64, 68] sts. On each side, you should have 2 strands of the same color: 1 working strand, and 1 long tail (see diagram “Bridge Setup” below). Trim the 2 tails to a shorter length for weaving in later.

Next, you will use the MC working yarn to knit the instep & foot. Leave the CC working yarn attached; you’ll pick this up later when you knit the cuff.

Bridging the Instep
This is a three-part process. Before you start, make sure your work matches the diagram “Bridge Setup” below – i.e., MC is active.
Magic Loop users: if your work doesn’t match the diagram, slip across the sts until you have access to the MC working strand. DPN and 2-circs users, you will have ready access to both MC and CC working strands.

Bridge Setup

1. Bind off half the sts with scrap yarn
With the scrap yarn, bind off the CC sts (half the total sts) using a simple chain bindoff. Leave the last bound-off stitch (in scrap yarn) on the needle. Your work should look like this (Magic Loop method shown):

2. Make a crochet chain with scrap yarn (requires crochet hook)
I recommend you watch Lucy Neatby’s excellent video on this process.
Move the st remaining from the bindoff in the previous step onto a crochet hook. Remove needle.

Place your L needle behind the crochet hook. Swing the scrap yarn around behind the needle and in front of the crochet hook.

With your crochet hook, pull a loop through.

Repeat these steps until you have a total of 38[40, 42] loops on your knitting needle. If desired, chain a few more loops off the needle like Lucy does in the video. On last loop, cut scrap yarn and pull end through.

3. Join the instep bridge to the other side of the heel
Hold the L needle and R needle tips together, and knit across the 38[40, 42] chain loops with the working yarn, in position shown.

Once you have knitted all the sts in the chain, continue knitting across the 30[32, 34] heel sts with your MC working yarn.

Instep & Gusset (to Toe)
In the previous section, you worked the first full round of the instep.
38[40, 42] sts on the instep, 30[32, 34] sts on heel. Round starts with the instep sts.

All rounds worked with MC.
Rounds 2-7: Knit.
Round 8: SSK, k34[36, 38], k2tog; knit to end of round. 66[70, 74] sts.
Rounds 9-10: Knit.
Round 11: SSK, k32[34, 36], k2tog; knit
Rounds 12-13: Knit.
Round 14: SSK, k30[32,34], k2tog; knit to end of round. 62[66, 70] sts.
Rounds 15-16: Knit.
Round 17: SSK, k28[30, 32], k2tog; knit to end of round. 60[64, 68] sts.

The first 30[32, 34] sts of the round form the instep; the second 30[32, 34] form the sole. Rearrange your stitches or place a marker to divide them up.

Foot
Knit in plain stockinette until the foot reaches over the wearer’s pinky toe, or about 1½ inches from tips of the toes. Begin toe decreases on the bottom of the foot.

All rounds worked with MC.
Round 1: K2tog, k to 2 before end of instep, ssk; k2tog, k to 2 sts before end of round, ssk. 56[60, 64] sts.

Rounds 2-3: Knit.

Repeat the last 3 rounds once more. 52[56, 60] sts.

Round 7: Repeat Round 1. 48[52, 56] sts.

Round 8: Knit.

Repeat the last 2 rounds 2[3, 4] more times. 40 sts.

Repeat Round 1 twice more. 32 sts.

Remaining rounds worked in CC.
Repeat Round 1 twice more. 24 sts.
Short row 1 [RS]: K2tog, k7 to 3 before end of needle, w&t.
Short row 2 [WS]: Sl1, p5 to 2 before end of needle, w&t.
Final round: Sl1, k5, worked wrapped stitch together with its wrap, ssk; k2tog, k8, ssk. 20 sts.
Graft remaining sts together.

Instep & Gusset (to Cuff)
Starting from the instep side, unpick the provisional cast-on and put the resulting 39[41, 43] sts for the instep on your needles. Then unpick the scrap yarn from the bindoff and put the resulting 30 [32, 34] sts on your needles.

Magic Loop users: Slip the heel sts purlwise from left to right needle until you have access to the working strand of CC.

All rounds worked in CC.
Rounds 1-6: Knit.
Round 7: SSK, k35[37, 39], k2tog; k to end of round. 67[71, 75] sts.
Rounds 8-9: Knit.
Round 10: SSK, k33[35, 37], k2tog; k to end of round. 65[69, 73] sts.
Rounds 11-12: Knit.
Round 13: SSK, k31[33, 35], k2tog; k to end of round. 63[67, 71] sts.
Rounds 14-15: Knit.
Round 16: SSK, k29[31, 33], k2tog; k to end of round. 61[65, 69] sts.
Rounds 17-18 Knit.
Round 19: SSK, k to end of round. 60[64, 68] sts.

Cuff & Bindoff
Work 12 rounds of in stockinette.
Ribbing round: [k2, p2] to end.
Repeat Ribbing round until your cuff is the desired height.
Second last round: With CC, [k1, p1] to end. Cut CC yarn.
Last round: With MC, [k1, p1] to end.
Bind off with MC using the Interlock Bindoff for [k1, p1] rib.

FINISHING
Weave in ends with tapestry needle.

Jeny Staiman is driven by a deep fascination with how things work, how people think, and how knitted fabric is constructed. Mild mannered usability research engineer by day, obsessive compulsive knitter by night, Jeny enjoys exploring creative approaches to all sorts of problems. She is a fledgling knitting instructor for the 2011 Sock Summit.

You can find her on Ravelry as curiousjeny and she blogs here.