Types of Gearing in Rowing
In this video, Lachlan runs through the four types of gearing in rowing. Most rowers are familiar with oar gearing, but this is only one piece of the puzzle. The other types of gearing are blade slip, oar dynamic gearing and span gearing. They all change the gearing at different points throughout the stroke.


Video Transcript
All right so today we're going to be having a look at gearing in rowing so there's four different types of gearing so the one most people are familiar with is static
static oar gearing
and that's typically say we've got our button here this would be our outboard with our blade this would be our inboard and so the gearing is how much how much movement at one end so the input which is this is the handle
to how much output we have
at the blade
but essentially we're looking at the handle compared to the work so say this is one meter this is two meters that would mean we have a gearing of one to two or because we're just always going to have the same handle movement we can just say we have a gearing of two so this is the only gearing that doesn't change throughout the rowing stroke so the other three forms of gearing all change when you all change throughout the rowing stroke depending on where you are mostly increasing around the catch so the second type of gearing we need to consider or thing we need to consider with gearing is blade slip
and so when the blade moves through the water so i imagine we've got the the water heat the blade here it's underneath the water as the blade moves through the water it slips a little bit it's not locked on so it can happen with a few little bits of air behind the blade maybe it's too shallow and so this blade slip can be thought to be about 10 to 30 percent
reduction in efficiency so this means that we have to times our original gearing amount by 0.7 to 0.9 and so the blade depth is important for reducing blade slip also the size of the blade and how fast the blades moving through the water but that's probably a bit beyond the scope of this video so the third form of gearing change is oar dynamic
gearing
and so imagine we've got our rowing boat here
Got our call it a bow mounted rigger and we've got the blade position so say our catch position here we'll call that 70 degrees so off the perpendicular got 70 degrees so if you were to have a catch position at say 60 degrees or if you had to have a catch position at say 80 degrees so depending on where your catch catch angle is would depend how much extra gearing you get so at 60 degrees it's two times the gearing of the static all gearing so in this case if we just forget about blade slip for a moment it would be four at 70 degrees it's three times so it'd be six six to one at 80 degrees it's about six times so you sort of end up if you have a graph here so
this this is angle so catch angle
and this is gearing
it would sort of look something like this so say this is our two mark as we indicated up here it would sort of come like this
and it becomes exponentially more so we're looking at about 60 degrees 70 degrees 80 degrees and so the further you come around towards the catch during the rowing stroke the the greater the oar gearing is going to become so the fourth type of gearing is span gearing
so the span of the rowing boat
is going to be so we've got our rigger here it's going to be the distance between here so if you have a greater span you end up with a decrease in gearing and a narrower span you end up with an increase in gearing and that's because if we think about the rowing boat so this is the rowing boat again most of the so the legs
and trunk
move
parallel with the rowing boat whereas the oar moves in a circular arc and so the handle moves in a circular arc and so what this means is that the oar handle is moving at a different speed to the shoulders so at the catch it's moving a lot slower than the shoulders are moving a lot slower than the handle so this increases gearing and so about 60 degrees catch angle it's around 13 percent increase in gearing
and so gearing is the sum of all of these parts so it starts off with the basics of static oar gearing you've got blade slip which reduces the gearing because it's because the blade slips a little bit through the water when you're moving it dynamic oar gearing the further you get towards the catch the higher the gearing gets it turns into an exponential increase the further you come forward with a large increase in gearing it around the 60 degrees and above mark and the span gearing is a smaller effect than the oar dynamic gearing but it can increase the gearing as well towards the catch
so total gearing
varies so the catch
it equals about six to seven square off
so square off is a position where the or is perpendicular so square off position it's around 1.7 to 2 because remember we lose a bit because of blade slip so that's just a quick introduction to gearing and rowing the four different types of gearing and how they affect gearing throughout the rowing stroke so this information and some of the illustrations are from a book called biomechanics in rowing by doctor Valery Kleshnev and I'd highly recommend you get a copy of this if you're more interested in the the uh the science behind the rowing stroke and the different forces involved but um yeah it's a really good read if you're into that sort of aspect of rowing
static oar gearing
and that's typically say we've got our button here this would be our outboard with our blade this would be our inboard and so the gearing is how much how much movement at one end so the input which is this is the handle
to how much output we have
at the blade
but essentially we're looking at the handle compared to the work so say this is one meter this is two meters that would mean we have a gearing of one to two or because we're just always going to have the same handle movement we can just say we have a gearing of two so this is the only gearing that doesn't change throughout the rowing stroke so the other three forms of gearing all change when you all change throughout the rowing stroke depending on where you are mostly increasing around the catch so the second type of gearing we need to consider or thing we need to consider with gearing is blade slip
and so when the blade moves through the water so i imagine we've got the the water heat the blade here it's underneath the water as the blade moves through the water it slips a little bit it's not locked on so it can happen with a few little bits of air behind the blade maybe it's too shallow and so this blade slip can be thought to be about 10 to 30 percent
reduction in efficiency so this means that we have to times our original gearing amount by 0.7 to 0.9 and so the blade depth is important for reducing blade slip also the size of the blade and how fast the blades moving through the water but that's probably a bit beyond the scope of this video so the third form of gearing change is oar dynamic
gearing
and so imagine we've got our rowing boat here
Got our call it a bow mounted rigger and we've got the blade position so say our catch position here we'll call that 70 degrees so off the perpendicular got 70 degrees so if you were to have a catch position at say 60 degrees or if you had to have a catch position at say 80 degrees so depending on where your catch catch angle is would depend how much extra gearing you get so at 60 degrees it's two times the gearing of the static all gearing so in this case if we just forget about blade slip for a moment it would be four at 70 degrees it's three times so it'd be six six to one at 80 degrees it's about six times so you sort of end up if you have a graph here so
this this is angle so catch angle
and this is gearing
it would sort of look something like this so say this is our two mark as we indicated up here it would sort of come like this
and it becomes exponentially more so we're looking at about 60 degrees 70 degrees 80 degrees and so the further you come around towards the catch during the rowing stroke the the greater the oar gearing is going to become so the fourth type of gearing is span gearing
so the span of the rowing boat
is going to be so we've got our rigger here it's going to be the distance between here so if you have a greater span you end up with a decrease in gearing and a narrower span you end up with an increase in gearing and that's because if we think about the rowing boat so this is the rowing boat again most of the so the legs
and trunk
move
parallel with the rowing boat whereas the oar moves in a circular arc and so the handle moves in a circular arc and so what this means is that the oar handle is moving at a different speed to the shoulders so at the catch it's moving a lot slower than the shoulders are moving a lot slower than the handle so this increases gearing and so about 60 degrees catch angle it's around 13 percent increase in gearing
and so gearing is the sum of all of these parts so it starts off with the basics of static oar gearing you've got blade slip which reduces the gearing because it's because the blade slips a little bit through the water when you're moving it dynamic oar gearing the further you get towards the catch the higher the gearing gets it turns into an exponential increase the further you come forward with a large increase in gearing it around the 60 degrees and above mark and the span gearing is a smaller effect than the oar dynamic gearing but it can increase the gearing as well towards the catch
so total gearing
varies so the catch
it equals about six to seven square off
so square off is a position where the or is perpendicular so square off position it's around 1.7 to 2 because remember we lose a bit because of blade slip so that's just a quick introduction to gearing and rowing the four different types of gearing and how they affect gearing throughout the rowing stroke so this information and some of the illustrations are from a book called biomechanics in rowing by doctor Valery Kleshnev and I'd highly recommend you get a copy of this if you're more interested in the the uh the science behind the rowing stroke and the different forces involved but um yeah it's a really good read if you're into that sort of aspect of rowing