Off-centre bottom bracket?? How come?

[Ugo51]

Hey everyone,

Jut out of curiosity I checked the space between one side of the crank and the frame, and compared it to the other side. It's different.
I checked all my bikes (admittedly only 3, but still) and they all have off-centre cranks. By how much, varies from bike to bike, roughly 2-3 mm. So not a lot, but still...
All bikes have square taper bottom brackets.

One of them actually, has the BB shell that is 67mm, not 68, but it's OK. At this point does it even matter?

But I guess this is not normal, right?

 

[novocaine]

Hey everyone,

Jut out of curiosity I checked the space between one side of the crank and the frame, and compared it to the other side. It's different.
I checked all my bikes (admittedly only 3, but still) and they all have off-centre cranks. By how much, varies from bike to bike, roughly 2-3 mm. So not a lot, but still...
All bikes have square taper bottom brackets.

One of them actually, has the BB shell that is 67mm, not 68, but it's OK. At this point does it even matter?

But I guess this is not normal, right?

Yes.

 

[Ugo51]

Yes it is, or yes it isn't?

 

[cce]

Old school loose ball bottom brackets often had asymmetric axles. More modern cartridge ones generally dont.

some way round i suspect this is the cause.

 

[Midlife]

My old steel bikes have a longer bit of axle sticking out of the drive side to leave room for the double chainset...... Is that what you mean?

 

[Ugo51]

I mean that when I measure the distance here highlighted in red, it's not the same on both sides

 

[FiveAlpha]

Lots of earlier bottom brackets were asymmetrical - sometimes longer on one side and sometimes the other.

I’ve just measured the length on each side of a Mavic BB and it’s been set with 20mm on one side and 17mm on the other.

 

[novocaine]

Yes it's normal.

 

[legrandefromage]

It's why I cycle around in circles

 

[novocaine]

It's why I cycle around in circles

no it's not, that's because your right ear is bigger than you left.