Double bass pedal: left spring tension higher?

[Tuj97]

Hi guys

I have this Pearl demon drive double pedal that I bought an year ago.

Now when I connect the two pedals together with the z-link drive shaft and set the spring tension to exact the same tension, it seems like the left beater is swinging slower than the right beater(slower for the beater to come backward). So after I realized that, I've set the left spring tension a bit tighter than the right and then swing for both beaters got exactly identical for like 8-9 seconds or so.

So my question is, is this normal for double pedals? I thought the left spring tension has to be little bit looser than the right or else the left pedal would be harder to push down than the main one.. I'm also having trouble trying to figure out in my case, if the left pedal is harder to push than the right pedal when the spring tension is higher on left side

Any helps would be appreciated thank you!!

 

[bud7h4]

That's normal. The drive shaft adds mass to the slave pedal, and the linkage makes the mechanics slightly more complex than the master pedal.
A little added spring tension is one way to compensate.

The increased tension on the slave spring should not be enough to make the pedal feel different than the master. On the contrary, it helps make them feel more the same. When the two beaters sway at the same speed that's a visual indicator that the pedals will feel as much the same as possible.

Again, I emphasize, In my opinion the goal is for both beaters to sway at the same speed (even if the master will almost always stay in motion longer).

 

[Tuj97]

That's normal. The drive shaft adds mass to the slave pedal, and the linkage makes the mechanics slightly more complex than the master pedal.
A little added spring tension is one way to compensate.

The increased tension on the slave spring should not be enough to make the pedal feel different than the master. On the contrary, it helps make them feel more the same. When the two beaters sway at the same speed that's a visual indicator that the pedals will feel as much the same as possible.

Again, I emphasize, In my opinion the goal is for both beaters to sway at the same speed.

Thanks man! Now it seems clear that the slave side spring tension has to be different to the main one!

 

[lefty2]

I've never bought into the swinging beaters test, simply because you're compairing apples to oranges. The linkage changes everthing about the way the beater swings. I just adjust mine to feel like I want it to feel under my feet. Having said that I have noticed that I do have the spring tention higher on the slave side, for me it's the right, lefty here.

 

[bud7h4]

I've never bought into the swinging beaters test, simply because you're compairing apples to oranges. The linkage changes everything about the way the beater swings.

Well, specifically the linkage adds mass and a mechanical component (joints); the slower beater (slower pedal) is showing you precisely the extent of that negative effect, and it needs to be corrected.
The spring adjustment corrects it, and evenly swaying pedals are literally indicating how similarly the pedals feel and perform. You want, for example, the beaters to rebound at the same speed right? That's one thing that an even sway signifies.

The alternative is to simply get used to uneven pedals.