The longer the blade the better the cut, general speaking.

One of the weaknesses of the Turfmaster, et.al, are the short blades.

My 3 blade 60" mowers cut better and clump less than my 3 bladed 48".

There was a time that Toro made a 3 blade 40". Operators complained about how much it clumped and clogged the deck.

 

Am I understanding this as the speed is still there with the smaller blades but it will throw clumps? Then I think it's slower if the clumps need to be tended to. I know on biweekly accounts my Turfmaster with cv224 wasn't always faster than my hrx217 with 200cc. The Honda went through almost anything full speed while the Turfmaster with slightly bigger engine had to slow way down to achieve the same cut quality.

 

No. A 42” is always going to be slower than a 48”.

as for 2 blade vs 3 blade. That honestly can not be compared in a scientific way unless your going to spend a lot of money to do it. Blade tip speed and a deck design play the biggest factor. Larger blades are nicer because they generally weigh more and have a higher tip speed but if the deck manufacturer accounts for it, they can under size the pulleys to achieve the same tip speed. Using your example. Is the discharge size the same on the 42” and the 60”? That will change the airflow.

the only one thing you can say for sure, a 48” is always going to be faster than a 42” simply because it’s larger. Under certain conditions maybe you slow the 48” unit down and under those conditions maybe the 42” will allow for a single pass vs a double pass with the 48”. But that should not be all the often. The 42 will always be slower in normal conditions.

 

sjessen is correct.

The dual blade 42 will be faster than the 3 blade 48 in lush turf.

This is one reason a 21" push mower eats the 30"'s lunch in Spring

I run several different brands of 16" blade units and 18" blade units. The 18" bladed units always perform best

 

Hindsight is always 20/20, if I knew that I would end up with something like the sw15 as a solid gate mower I might have been a tiny bit better off with the Wright 42. This post isn't about me second guessing my 36" stander purchase because I'm happy with the Deere.
I guess it's more about is a 48" 33% faster than a 36" because of the extra 12" or is there a loss in efficiency making it not a night and day difference, especially when you add gates into the equation. In a nice thick healthy lawn.

@sjessen what was the toro or Exmark you were talking about with two 24" blades? I'm pretty sure you said it's just being considered but it's a cool sounding idea.

 

If there's a lesson to be learned here and I don't believe there is.... never buy anything in case one might find something better in the future

 

Well, to test your question out in as fair a way as I can, I mowed some thick grass with my 60" deck, then removed one blade to make it a two blade mower. Trust me, the cut was better with three...................................

 

Possibly you removed the incorrect blade?

 

The 2 blade 48 sjessen referred to is happening. It will likely make the machine too long though. I like the 42 or 44 sizes w/2 blades but they not common

 

@Hurryupelectric Here you go.

 

Just because they built it doesn't mean it's good. Keep in mind that mower is target selling to home owners not commercial operators. Less blades= less cost= more units sold= profits.

 

None of us contain enough information and testing to prove any of what is posted to be correct. A small blade can have the same tip speed as a big blade. No one has mentioned engine HP , blade type, blade/deck clearance, discharge size opening, deck design.

no one has brought up more turns on The smaller mower. Turns don’t mow grass. Turns don’t make money.

for reference a 48” uses smaller blades than a 36. A better comparison is 36 vs 52. Which is 33% faster.

 

None of us contain enough information and testing to prove any of what is posted to be correct. A small blade can have the same tip speed as a big blade. No one has mentioned engine HP , blade type, blade/deck clearance, discharge size opening, deck design.

no one has brought up more turns on The smaller mower. Turns don't mow grass. Turns don't make money.

for reference a 48" uses smaller blades than a 36. A better comparison is 36 vs 52. Which is 33% faster.

Isn't tip speed pretty much the same across the various deck sizes?

 

In order to properly compare. You would need to use a 36 and 52. Then make sure your motor had the same HP ratio. And the deck discharge opening would have to have airflow and air speed ratios the same. Deck depth would need to be the same. And on top of all of that , different turf types will act differently.

 

@Turf Tracer, I believe said that 21" is about as ideal for mowing blades as possible. That's why I started the thread with the Wright examples.

 

I’ve got eXmarks and Wrights in 32 48 and 36. Same deck style on the eXmarks and Wrights same engines same type of blades. Every single 18” blade unit cuts better that the 16” version. That’s enough evidence for me.

 

If you just theoretically had a 14" blades in a 3 blade setup vs let's just say 2 18" blades to get a 36" cut (yes I know the blades would be hitting each other but stick with the math). If the rpm of each shaft was the same regardless of which set up... Let's just assume 5k rpm just to give a base line. The tip speed of the 18" blades would be 267 MPH. Run the same calculation on a 14" blade and you get a tip speed of 208 MPH. About a 30% difference which is quite substantial.

 

The BOP 36” had a 3 x 12” blade set up and ran at crazy high rpm. Cut was good in ideal conditions only.

 

significant difference in Spring here. I won’t even use my 16” blade units in April. Once the growth slows in June it don’t matter so much.

 

significant difference in Spring here. I won't even use my 16" blade units in April. Once the growth slows in June it don't matter so much.

But is that because of the blade or because of the blade tip speed being reduced. Is the HP ratio the same?