Is it normal to zercher squat 3 times less than one can back squat?

Question

I've done a set of 180kg x 5 lowbar backsquat today (hip crease below knee), and decided to follow up with zerchers. I could not do more than 3 reps with 100kg, and ended up doing 3 sets of 60kg x 4-5 reps, each set to failure, failure happening because I was unable to stand up straight with the barbell. Zerchers were done off pins, not off the floor. The back squat set was relatively easy, and did not fatigue me much.

I've never done zerchers before. Bodyweight 100kg, height 180cm, rest periods ~5 minutes between sets.

Is such a large difference between these two types of squat normal (for example, because my core or quads are too weak) or am I doing something very wrong?

Answer 1

It's normal to not be good at a new lift, even if that lift is a variation of a basic exercise that you already do. It takes time to develop technique, strength, self-knowledge, and self-confidence in a new kind of squat. Each kind has its own particular needs, each of which exposes a different weakness in the athlete. So it's not surprising that 60-100kg gave you trouble even though you can hit 180kg in a variation you're well-practiced in.

It's good to focus on a particular kind of a lift for a long while, because it's the best way to develop general strength and other attributes. But that means accepting the fact that you won't be able to push similar numbers in other variations of that lift.

That said, front-loaded squats (front, zombie, Zercher, goblet, sandbag...) and back-loaded squats (lowbar, highbar) are quite different, and develop different qualities. Of those, most people consider the lowbar squat the best way to move the most weight. For instance, it's common to expect one's front squat to be about 80% of one's back squat if the two are equally trained. The Zercher is basically a more difficult, painful, and awkward front squat, and you haven't trained it ever before, so it shouldn't be surprising to discover your max is about half of your well-trained back squat. Even if you trained the Zercher squat rigorously for some time, it's unlikely you'd ever break 120-135kg in that lift without needing to push your back squat much higher.

Answer 2

"Normal", probably not. "Reasonable", sure.

It's not normal because most people can't do sets of 5 squats at almost twice bodyweight in the first place. Of those who can, most of them do Zercher squats now and then.

Reasons why you had issues probably include:

1. you don't have the same level of technique that you have for back squats. This is probably the biggest single reason (says the guy who doesn't know you, didn't see you lift,...)
2. while there is a lot of overlap in which muscles are used, it's not 100%, and the weakest link defines the chain
3. you tried them after you did your set of back squats

am I doing something very wrong?

If you care about Zercher squats (or the real life motions they replicate), then yes. If you don't care about them at all, no. At a bet, getting somewhat better with them than you are now will probably help you avoid injury (but be careful during that initial "getting better" phase), but there's no magic weight or ratio. If you enjoy them, do them. If you're preparing for something a lot like them, do them. If not, don't stress about it.