Study: Big Blade vs. Macon (PubMed)

[igoeja]

A fluid dynamic investigation of the Big Blade and Macon oar blade designs in rowing propulsion.

Caplan N,
Gardner TN.

Health, Exercise and Sports Performance Research Group, Division of Sport Sciences, Northumbria University. Newcastle-upon-Tyne.

The purpose of this investigation was to examine the fluid dynamic characteristics of the two most commonly used oar blades: the Big Blade and the Macon.

Scaled models of each blade, as well as a flat Big Blade, were tested in a water flume using a quasi-static method similar to that used in swimming and kayaking research. Measurement of the normal and tangential blade forces enabled lift and drag forces generated by the oar blades to be calculated over the full range of sweep angles observed during a rowing stroke. Lift and drag force coefficients were then calculated and compared between blades.

The results showed that the Big Blade and Macon oar blades exhibited very similar characteristics. Hydraulic blade efficiency was not therefore found to be the reason for claims that the Big Blade could elicit a 2% improvement in performance over the Macon. The Big Blade was also shown to have similar characteristics to the flat plate when the angle of attack was below 90 degrees , despite significant increases in the lift coefficient when the angle of attack increased above 90 degrees . This result suggests that the Big Blade design may not be completely optimized over the whole stroke.

[Snail Space]

That's a strange one for PubMed!

[PaulS]

Thanks for the abstract and summary.

IMO, The only real advance in blade design has been the Apex R (Oval).

There is no such thing as "optimized over the entire stroke" in oar blades, the angle of attack is rapidly changing, and eventhe direction of flow reverses during the stroke, admittedly very tough to "optimize" for that set of variables.

The "Cleaver" style blades are optimized for "The big finish" technique in force application profile, and the Macon optimized for the "Front loaded" techique. As fate would have it, the "Front loaders" will not be helped by the "Cleaver" blades, but the "Big Finishers" would not do well with the Macons. So while the 2% figure is probably accurate, it's only for the group that fits the profile.

http://www.biorow.com/RBN_en/2004RowBiomNews02.pdf
Rower 1 - Front loaded
Rower 2 - Big Finish (more like "big middle", but that's even more what the Cleaver is optimized for)

Big Blades - Rower 1 wins
Macons - Rower 1 wins by more
Macons for Rower 1 Vs Big Blades for Rower 2 - Rower 1 wins (difficult to say if margin would change)
Big Blades for Rower 1 Vs Macons for Rower 2 - Rower 1 wins big

Big Blades for Rower 2 Vs Macons for Rower 2 - Big Blades produce a better time. (Maybe the 2% oft cited)

[Bob S.]

The "Cleaver" style blades are optimized for "The big finish" technique in force application profile, and the Macon optimized for the "Front loaded" techique.

Cleaver. That's a new one on me. I had only heard them referred to as hatchet. But cleaver is certainly a closer match in shape.

Incidentally, in the '40s, one of our coxswains, an engineering major, was experimenting with a similar design and testing it with strain gauges. The coach was very interested in the work. I think that the main problem in those days was that it was difficult to make them in quantity with wood. It wasn't until the new materials for oars were developed that it became practical.

Bob S.

[Byron Drachman]

Hi Paul,

I've read various times people expressing the opinion that it is easier to get a back injury (assuming one is prone to back injuries to begin with) with the larger blades. I suppose the idea being that with the Macon if you overload too much, you just get more slip but can't "pry" against the water as much. What do you think? Are there more back injuries now that most rowers use the larger blades?

Byron

[Nosmo]

IMO, The only real advance in blade design has been the Apex R (Oval).

Interesting. In my circles the Apex R does not seem to be very popular. The hatchet Drehers are the most popular in my club but only one person ever bought the Apex R. I've rarely seen them, but I have thought that it was an interesting idea.

One of the more senior sculler in my commented that the biggest advantage of the hatchet was the reduced likelihood for crabs among novice crews. And the efffect of blade design was so much less then the more subtle variations in the technique of the catch, release and blade depth.

[PaulS]

Hi Paul,

I've read various times people expressing the opinion that it is easier to get a back injury (assuming one is prone to back injuries to begin with) with the larger blades. I suppose the idea being that with the Macon if you overload too much, you just get more slip but can't "pry" against the water as much. What do you think? Are there more back injuries now that most rowers use the larger blades?

Byron

Bob,
"Cleaver" and "hatchet" are used generally interchangeably, but some will make a distinction between Sweep (Cleaver), and sculls (Hatchet). Probably best to just go with what the manufacturers call them.
Smoothie - Cleaver or Hatchet
Fat Smoothie - Cleaver or Hatchet with deep belly
Big Blade - Cleaver or Hatchet
Macon - Well, you know...

Byron,
It does seem that there is an increase in the prevalence of back injuries among rowers, though I'm not sure if it an equipment issue or just better reporting of injuries.

The "Big finish" or "Big Middle" that is encouraged by the Cleaver type blades, and that blades ability to lessen slip when it is in the "stalled" condition could well be part of the problem.

Early in the Drive, when the blade is very acute to the hull, there is very little slip at all, regardless of the blade type. For those that are very quick at the beginning, perhaps a softer flex shaft would be in order. The softest Carbon shaft these days is close to what the stiffest wooden shaft of old would have been. IMO, most folks are rowing with shafts that are too stiff for them. A softer shaft will do a lot to help the rower that is trying to learn the classical technique by giving just a bit more time for things to happen, loading at the catch and release at the finish.

IMO, if one really wants to learn how to row well, they should do so with the Macon (Or ApexR) blades. Males in particular would benefit from the change because it would help to put the importance of using the legs effectively and quickly into focus, instead of the normal "hork on the handles with the upper body" method that they like to employ. Sure it "feels" hard, but that's because the legs could supply the same force with ease, and for a much longer period of time. Women seem to pick up the use of their legs much more quickly, perhaps because they generally have less upper body strength to rely on.

[PaulS]

IMO, The only real advance in blade design has been the Apex R (Oval).

Interesting. In my circles the Apex R does not seem to be very popular. The hatchet Drehers are the most popular in my club but only one person ever bought the Apex R. I've rarely seen them, but I have thought that it was an interesting idea.

One of the more senior sculler in my commented that the biggest advantage of the hatchet was the reduced likelihood for crabs among novice crews. And the efffect of blade design was so much less then the more subtle variations in the technique of the catch, release and blade depth.

The Dreher Hatchets are quite nice (for hatchets), as the chord of the shaft nearly bisects the blade and makes the handling characteristics closer to a Macon than to C2 or Croker Smoothies. I wouldn't expect the ApexR to gain popularity particularly quickly as they do not offer a "quick fix" to the typical bad practices that are so common these days, in fact they highlight exactly those bad practices for what they are. It's a lot like the oversized and perimeter weighted golf clubs Vs the older Forged blades. Sure one has a really large "sweet spot", making it seem that you can do no wrong with them, but given enough time our inherent tendency toward entropy will take over and allow for bad habits to creep in, unnoticed at first, but by the time they get noticed they are well ingrained and harder than ever to get rid of.

We start off each season with Macons, and ensure that we get to a desired speed standard prior to switching to the ApexR, which are so easy to be clean with that attention and effort that goes into making sure we are clean with the Macons can be redirected at improving the speed. The ApexR's are also a bit lighter, so it makes rating up easier, for some very quick acceleration. It can stun your competition when you make a jump in boat speed of 1m/s over 5 strokes and take 15-20 meters out of them in the next 10 strokes. Then you get to relax and enjoy the lead until they make a run at you that you are in a good position to see coming and hold off.

The funny thing about new or unusual equipment is that there is an assumption that you get something for nothing, i.e. terms like "faster blades" are bandied about. In the end, it's the horse, not the horseshoe or chariot. It's really rather silly to think that anyone else won because of their equipment, and even worse, it's a bit insulting to the winners to suggest as much, just congratulate them on being good enough to have emerged victorious over the challenge of the competition they had.

[Rockin Roland]

Cleaver blades arrived on the scene just before the Barcelona Olympics however a similar blade shape actually dates as far back as the year 1880 when Yale University used them.

Cleavers were the first major change in oar shape since the 1960s and the fuller shorter blades with increased angle at the top allowed entry to be parallel with the water surface and water did not flow over the top.

Croker introduced a flatter form of cleaver blades and offer "cut offs" (cut down blade surface area version for lightweight rowers). The larger fuller blades together with stiffer shafts are recommended for the bigger and more powerful rowers as the extra load and less flex can cause injury.

One also has to take into account what these bigger blades do to sculling. Sculling has become physically harder than sweep oared rowing because the total surface area of two sculling blades is greater than the surface area of one sweep blade. They therefore require more physical effort to move through the water.

[Snail Space]

Fascinating thread, but ...

Macon - Well, you know...

... is that a champagne flute shape?

[PaulS]

Fascinating thread, but ...

Macon - Well, you know...

... is that a champagne flute shape?

Yep, or champagne Bottle shapped, or some call it "Tulip" shaped. (though I don't see too many Tulips shaped that way)

[Snail Space]

Thanks, Paul.