Gauge too heavy for Fretless??

[shane-0-matic]

Being the West Ham United and Iron Maiden fan I am, I decided to put the Steve Harris Sig Flats on my Fretless. Ive got the action as low as possible at the saddles, And the neck is pretty much straight, A slight amount of relief. (If I dont have the action this low the bass is fairly hard to play. It is a Cheap Stagg Fretless)

No matter what I have done to the setup the strings buzz against the fingerboard when playing a low note on the neck (Where the 1st fret would be).

Am I simply playing too high gauge of a string? Or is there anything I can do setup wise to correct the problem and keep the bass playable. Thanks!

EDIT: I have also shimmed the neck on the bass with a couple of dense business cards, maybe 3/4 of an inch wide, at the side of the neck pocket closest to the pickups. I did this before i put the new strings on.

[eukatheude]

Try giving the neck a little more relief, less than a quarter turn should do.

[FourBanger]

Yup, sometimes bigger strings need a little more room to shimmy.

[JLS]

Answer, above.

[shane-0-matic]

I dropped down to medium gague rounds and im still having the problem. Gonna add some more relief and try to keep it playable, If that doesnt work, Should I consider a new nut?

[JLS]

Add more relief. If that doesn't work, see my previous reply.