Why not 2 curved Edges on a Trem knife?

[Metallion]

Why do Ibanez use One Straight and one Curved Edge on the Tremolo Knives?
Why not Both Curved? Like Floyd Rose.

Seems mostly to be durability problems with a straight knife edge.
A round holds better, I gather.

Also: Have anyone Replaced the Knives on a Ibanez trem?
Harris sells spare "Knife Edge Sets", so it should be possible.

[David McCarroll]

Well, that's a pretty easy one to answer - if both knife edges were curved, the post spacing would have to be incredibly exact, and incredibly consistent from guitar to guitar, otherwise the trem wouldn't sit correctly on the studs - one curved knife edge effectively locks the lateral position of the bridge and stops it from moving sideways, while the straight knife edge allows for a little bit of inconsistency and error in the positioning of the posts.

I don't know if the curved edge is more durable or not (as both knife edges ina perfect world would kiss the post on exactly one atom....), however i would imagine it is harder, hence more costly to machine a good curved knife edge than a straight one.

[Tank]

From a physics point of view you are correct, the one angled edge will leave better margin for little errors in the post alignement.
Also stability is an issue. The straight line beneath stabilizes the knife edge and it should be more durable and hold its "sharpness" longer.

But thats theory, we see that both work fine...

[chris101]

Originally Posted by David McCarroll

Well, that's a pretty easy one to answer - if both knife edges were curved, the post spacing would have to be incredibly exact, and incredibly consistent from guitar to guitar,

Are you saying that Ibanez dont have the CNC equipment or skills to produce accurate post holes? ;-)

[Scali]

Pfft, knife edges are so 80s... ball bearings, people!

Speaking of 80s... I had a guitar with high-end Schaller trem, and the knives were actual insets of hardened steel... The rest of the bridge was other material.
That thing lasted forever.
My LoPro Edge never failed me either, but you could see a big wear-mark on the straight edge.
I've heard a lot of horror stories about Lo-TRS and other cheaper trems that get dull really quickly because they use cheap and soft metal for the knife edges, completely ruining tuning stability and all. But I've never used any of those. I've only used the Schaller, the LoPro Edge, and the ZR-7 for a prolonged period. No complaints on any of them, but the ZR sure looks coolest

[brothersnowgone]

Originally Posted by chris101

Are you saying that Ibanez dont have the CNC equipment or skills to produce accurate post holes? ;-)

Sure they are capable of doing it, anyone with a cnc is. It's just easier and less costly/time consuming to just make one knife edge find home.

[crevis]

Originally Posted by brothersnowgone

Sure they are capable of doing it, anyone with a cnc is. It's just easier and less costly/time consuming to just make one knife edge find home.

Ibanez don't manufacture the TRS, they are generic and sold to many guitar companies so I imagine it would be for inconsistancies between guitar manufacturers.