BB / Axle height

rockmonkeysc

I have seen a few comments about how having a low BB relative to the axle height is good for handling but I can't quite work out why.
I understand that a low BB gives a low overall c of g but how does it's height relative to the axles make a difference?
I have googled it and can't find anything which explains the physics of what (if anything) is happening.

poah

is it to do with cornering? got no idea though - low BB means more pedal strikes which is what I'm getting with the ghost compared to what I had with the orange

The Rookie

The BB height is relative to the axles as bigger or smaller tyres raise and lower the BB relative to the ground but not the axles.

buddy_club

The Rookie wrote:

The BB height is relative to the axles as bigger or smaller tyres raise and lower the BB relative to the ground but not the axles.

Surely the height of the axles relative to the ground would change with bigger or smaller tyres? Or have i misread that and your talking about the distance between the BB/Axles?

rockmonkeysc

What I mean is that people are claiming that a 29er with a 13" bb height will handle better than a 26" bike with a 13" bb height because the bb is lower relative to the axle height (13" is just a random height).
I can't think of a logical reason why it would make a difference. The BB height from ground is important because it has a major effect on bike/rider combined c of g.
I like a low bb, you have to time crank strokes to avoid pedal strikes sometimes but I think it's worth it for the handling.

lawman

RockmonkeySC wrote:

What I mean is that people are claiming that a 29er with a 13" bb height will handle better than a 26" bike with a 13" bb height because the bb is lower relative to the axle height (13" is just a random height).
I can't think of a logical reason why it would make a difference. The BB height from ground is important because it has a major effect on bike/rider combined c of g.
I like a low bb, you have to time crank strokes to avoid pedal strikes sometimes but I think it's worth it for the handling.

All to do with C of G in comparison to axles. Try riding a 13" bb on a bike with 16" wheels you're gonna feel pretty damn perched on top of it. The lower the BB in relation to the axles the more likely you are feel "in" the bike rather than "on" it. The distance between the axle centreline and BB has arguably more influence than BB height alone, but there's a whole lot more to it than simply saying one is better than the other, some people can feel the difference more than others and bikes vary so much what works on one won't necessarily work on another.

rockmonkeysc

What im looking for is a more scientific explanation. Im not saying I don't believe it, I just can't understand how or why it could make a difference.