Adjusting the Front and Back Crotch Seam on Your Jeans Pattern

Ok...sorry for the delay on getting info to you about adjusting the front/back crotch seam on your jeans to get rid of extra fabric that's bunching up either under the front zipper or butt.    Let's take the front crotch seam first.  I just want to throw out this disclaimer--There are lots of reasons why this might be happening.  Here's my short list of what I think they could be:

1. The front fly zipper is not sewn in correctly.
2. The angle of the front crotch seam is not compatible with the shape of your waistline/hips.
3. The curve at the bottom of the crotch seam is not "curving" with your shape down there.

Let's take no. 1 first.  When you're sewing the front fly together, it's important that the pieces were all accurately cut out.  For example, if you "added" a little by not cutting out the zipper seam allowance exactly on the line, you've got extra fabric along the center front of your jeans.  This tiny mistake can be magnified by not using the exact seam allowance (making the amount of extra fabric even greater).   Then when you insert the zipper the overlap of the right and left leg needs to be exactly right.  If you don't overlap the pieces enough, the extra fabric causes the fly to pull way from the body when the zipper is zipped up. Finally, when you're sewing the fly piece down when you're topstitching the fly detail, everything needs to be pressed perfectly flat. If the leg piece is bunched up under the fly piece, that's not good either.  All of this can affect the front crotch and how it fits...because it's directly attached to the bottom of the fly.

Now, in no. 2, I'm referring to the angle that the crotch seam takes from the waistline at the center front.

The original front leg piece illustrated above has a front crotch seam that angles out slightly as it progresses towards the curve at the bottom of the seam.  This is perfect for anyone who has a defined waistline.  The angled front crotch seam acts like a dart giving the front waistline the shape to sit on a smaller waistline.  If you either do not have a defined waistline, or if you are wearing your jeans on your high hip (instead of closer to your waistline) the angle in the front crotch seam will cause extra fabric to push into the center of the jeans.  The sides of the waistband are being pushed down because there isn't a waist for them to sit up into.  This extra fabric can show up at the bottom of the fly zipper.

The pink line represents the front crotch seam that would fit a shape without a defined waist.  If your jeans are hanging off your waistline properly, there isn't extra fabric being pushed into the center front to cause fit problems.  

Finally, to address no. 3--Notice, I've also played with the shape of the curve as well.  This is an area that you may need to play with a little to refine the fit of your jeans.  The curve needs to follow your shape...it's a subtle adjustment, but it can make a big difference.  You may need less or more curve than the pattern piece is giving you.

....Please if you have questions, shoot me an email, I'll try to individualize answers depending on your specific situation. 

Now, for the back crotch seam... check out this post I did in November--How to Smooth the Wrinkles Behind the Leg.  Questions...please let me know!  

Hope that was helpful...Jen