I have had no problems with their zippers. Of course I take care and fold my kites down very neatly before putting them in the bag. There is no strain on the zippers when your kites are folded properly for storage/travel.
Seems like some years are worse than other.
What year are the bags (not the kites )?
I broke one zipper on my 2015 bag when my bag touched the lip of the car boot. It snapped in half on the spot. And that was the extension pouch zipper, zero pressure on there.
The other two zippers just stopped zipping properly, and eventually let go of the zip. I will admit there was sometimes a bit of pressure on the zipper, but nothing it should not be able to handle.
I know my warranty + extended warranty period has expired, but if anyone at North is reading this, please consider sending me a replacement.
My kite with the broken bag is a 12m North Dice. I would understand if you sent me a 2017 or 2018 as a replacement. Also, the bag for my 9m is showing signs of fatigue, and you could save on shipment if you sent me both together.
My local shop owner told me North will get you an OEM replacement bag for $60. I passed on it, but that is your best bet, I think.
Seems like some of the best kite makers have some room for improvement with their bags. My new Nash kite bag left me underwhelmed (kite is outstanding) so I switched bags and now carry it in my 2011 Cabrihna bag.
Maybe it's time for some collective actions? All these who purchased North kites within last 12 months should bust their zippers and apply for a warranty replacement. That should run into some thousands globally. After replacing that many bags - a few times perhaps - somebody at North will start thinking.
All 6 of my 2016 North zippers broke within 8 months. My one 2017 broke within 6 months. I would love if North would replace them. Its obviously a defect. Ive never seen Cabrinha bags with broken zippers.