does 0.5mm matter in bb axel length?

[scottproonly]

Hi. I just had someone turn down a bb from me because it was 117 not 117.5. Now .5mm means .25mm each side! Surely this is too small an amount to matter?
I'm not slagging them off its their choice I just can't get my head round why .25mm would have a noticeable affect on anybody's chainline!
If they are reading this let me assure them I am not trying to offend them!
Maybe I am totally off on this one!??

 

[Retro Spud]

Hi. I just had someone turn down a bb from me because it was 117 not 117.5. Now .5mm means .25mm each side! Surely this is too small an amount to matter?
I'm not slagging them off its their choice I just can't get my head round why .25mm would have a noticeable affect on anybody's chainline!
If they are reading this let me assure them I am not trying to offend them!
Maybe I am totally off on this one!??

Ahh you obviously sold to Richard Cranium :facepalm:

Honestly are they for real.... Is this post for real

Move on fella you obviously sold to the wrong person and you'll never satisfy them.

 

[FMJ]

Now .5mm means .25mm each side! Surely this is too small an amount to matter?

As my friend is fond of saying, that's 8 inches on the internet.

 

[xxnick1975]

What did you advertise it as?

 

[mattr]

If it was square taper that's probably less than the variability in the soft aluminum crank, or the difference between max and min torque tolerances, or the difference between a brand new crank, and one that's on its second or third bottom bracket.

Bit pointless really.

 

[scottproonly]

I did advertise it as 117.5 because that's what it said on the box when I bought it many moons ago. They asked me to measure it and it came up as 117.
Oh well it'll find a home one day!

 

[grarea]

Re:

Am I right in thinking that getting your chainline right only works for the middle gear?
Or, rather, one gear... (Ignoring any dirt or grease on anything).
Once you change gear you are away from the most efficient chainline anyway.
Is that right?

I am pretty sure I have .25mm travel in my chain.

Are you sure that your ruler is accurate?

 

[raidan73]

Probably 0.5mm tolerance in manufacture, or at least your measuring device Either way it won't make the slightest difference

 

[FluffyChicken]

Re:

No difference assuming they are the same design


117.5 are often called 118 now.

Also it varies manufacturer to manufacturer on how they have their taper made, their tolerances.
Suntour I think specified +-1mm on chainline.
Shimano has 2.5mm ;-)