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Author Topic: Rowing Question?  (Read 1364 times)

Martin [Admin]

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Rowing Question?
« on: January 25, 2018, 11:23:19 pm »


Rowing Question:
Why does the geometry of rowing usually leave the oars crossing over at the 'finish'?
This seems a very awkward position for the arms & hands...



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raflaunches

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Re: Rowing Question?
« Reply #1 on: January 25, 2018, 11:44:50 pm »

Judging by the footage itís probably to get the full range of movement and the crossing over is just the price to pay for this movement.
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RST

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Re: Rowing Question?
« Reply #2 on: January 26, 2018, 08:28:55 am »

That's called sculling and I was useless at it (I was a bowside sweep oarsman back in the day -left me lop-sided for years afterwards!).  I never asked the question myself back in the day but thinking how my arms crossed when I did scull and how they were straight to get a good pull I guess the geometry worked throughout the stroke.  I always struggled with my knuckles wrapping and could never get the balance at the end of the stroke.

The oars don't cross-over at the finish though -it's about half way inbetween unless you're just manouvering slowly.

Rich
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tonyH

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Re: Rowing Question?
« Reply #3 on: January 26, 2018, 01:48:40 pm »

I reckon that if the length of the lever between the rowlock and the hand is greater, less effort is needed.


 %)




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Bob K

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Re: Rowing Question?
« Reply #4 on: January 26, 2018, 03:16:57 pm »

I love rowing.  I used to cox the school first eight back many years ago.
Even though Dorney Lake is just a couple of miles from where I live I just couldn't get a ticket for the London Olympics - any session, so had to watch it on TV like most everyone else.

PS:  Rowing eights are a lot trickier to steer than it may look.  Rudder response is very slow so you had inch it, wait, inch it etc.
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Liverbudgie

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Re: Rowing Question?
« Reply #5 on: January 26, 2018, 06:05:57 pm »

I reckon that if the length of the lever between the rowlock and the hand is greater, less effort is needed.


 %)

If that is the case all you'll do is ground in circles! Though in full racing fettle the distance between the button and the inboard end of the scull can be adjusted to suit individual requirements.

At the point when the handles meet one goes under the other, in which way this happens is dependant on the sculler. In my case the stroke side scull went under the bow side scull. The sculls don't crossover at the end of the stroke, but at a point about three-quarters through. You then recover to the "catch" position i.e. the start of the next stroke by pulling yourself down the slide with you feet, which usually these days are in training shoes screwed in the "stretcher"

Steering an "eight" or any other boat is really quite easy, all you have to remember is to apply the rudder when the blades are in the water, otherwise the balance of the boat will suffer and the cox will, I assure you, face the wroth  of the crew in a number of ways.

LB

ex LVRC.

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Bob K

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Re: Rowing Question?
« Reply #6 on: January 26, 2018, 07:00:42 pm »


Steering an "eight" or any other boat is really quite easy . . .,


Woah there !  An eight is far from "easy", due to it length vs narrow beam and slow rudder response.  A tiny touch too much or a moment too long and you get it slightly weaving through overcorrection which rapidly reduces speed.  It is an art which takes a lot of practice time to acquire.  Coxed three Head of the River events in which our boat did very well.  Of course, to be a good cox requires you to be light and have a very load voice  {-)
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tonyH

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Re: Rowing Question?
« Reply #7 on: January 26, 2018, 08:07:04 pm »

Sorry LB but I'm confused %%

Each end of the oar travels through the arc of a circle and the oar is a simple lever where the rowlock is the fulcrum.
The effort of the rower pulling on the handle acts on the water at the blade end and the force on the water can be altered by the relationship between the two distances between (a) the fulcrum and the grip and (b) the fulcrum and the blade.
The longer (a) is relative to (b), the less the effort to produce a given force on the water.
If, therefore, the length (a) is extended, the hands will overlap, generally when the two oars are co-linear and there are only two options. 1. More propulsive thrust will be generated or 2. less effort will be required for a given thrust.

Even if you consider the water as the fulcrum and assuming zero slippage, the effect is the same.

The overlap is more obvious when a single rower has a pair of oars but the lever principle is the same in all cases.

I think this stacks up.

Tony
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Liverbudgie

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Re: Rowing Question?
« Reply #8 on: January 26, 2018, 08:17:57 pm »

Woah there !  An eight is far from "easy", due to it length vs narrow beam and slow rudder response.  A tiny touch too much or a moment too long and you get it slightly weaving through overcorrection which rapidly reduces speed.  It is an art which takes a lot of practice time to acquire.  Coxed three Head of the River events in which our boat did very well.  Of course, to be a good cox requires you to be light and have a very load voice  {-)

1) In a shell that is quite correct and it does take a fair degree of experience to keep the boat straight and balanced but, that as with most things, comes with experience. On the other hand a clinker or restricted boat, yes I do go back that far, is easier to steer especially for a novice or relatively inexperience cox were a light touch is not necessarily a good thing and, can lead to disaster if your not careful, I'm thinking here of the West Float at Birkenhead or the Dee or even the Tideway.

2)Well, I ROWED IN FOUR TIDEWAY'S Therefore I did not sit in the back of the boat shouting my head off. O0 Though you being in a Thames club I would have thought that you would have had a mic and speakers to convey your instructions {-)

For those of you who haven't got a clue as to what we talking about the Tideway Head race takes place on the Thames in late march and usually a week before the Oxford and Cambridge boat race. The race is over the same course as the Boat Race but runs in the opposite direction. Up to 450 crews can take part and they come from all parts of the country and further afield as well.

LB

 
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dave301bounty

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Re: Rowing Question?
« Reply #9 on: February 14, 2018, 07:34:02 pm »

i see the lvrc have a problem . and by the way I was a bow oar in the crew that won the 1958 whaler pulling at Surbiton ,got the bronze to show ..
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tobyker

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Re: Rowing Question?
« Reply #10 on: February 14, 2018, 09:36:57 pm »

If the handles of the sculls don't cross over in the middle, they will be too far apart at the beginning and end of the stroke for the rower to have proper control of them, and they will tend to pull inwards. This will pull the button away from the rowlock, making it difficult to feather the oars properly.
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RST

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Re: Rowing Question?
« Reply #11 on: February 15, 2018, 01:44:48 am »

Quote
i see the lvrc have a problem . and by the way I was a bow oar in the crew that won the 1958 whaler pulling at Surbiton ,got the bronze to show ...

Lol, I was National Champs and British unis Gold medal winner -still couldn't scull for life or death of me and I never thought steering an 8 was that hard. I could scull to some extent but can't explain why I found it so hard to balance -It was apparently comical from the riverbank.

Back in the day my Sat morning was a 5k+ run at 6am, 10k rowing on the Clyde, mixed discplines. breakfast, anther 10k on the river.  Broke off from the mens boat at this point before lunch, had 2-3 hrs to kill before coaching ladies.  So another 3 hrs on the ergometer with some decent music to kill time (maybe 20-25k), then another hour or two running up the bank and back coaching ladies squad (I was too heavy to cox too much) so that was probably another 8-10k running.  Monday nights was always a 10mile+ run.  Tuesday 2hrs of circuits, Wednesday at least 10k on river at 6-7am plus I probably went to gym or ran 10k, Thursday same, Friday same.  Sunday we probably did a 5k "light" session on the river but I sometimes got bored and did a 20k erg to ill time afterwards depending on hangover.

Have been crew with some ex-commonwealth games guys and won some heads -lost some, was OK at long distance, never so good at sprints.

...I was a bit nuts for rowing and at uni. Unfortunately I found it a very political / bitchy sport and after capataning our club I lost heart somewhat.  Never kept it going since.
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