Riding mower--2 blade vs. 3 blade?

[Pilot]

I'm going to replace my 12 yr. old Cub Cadet, probably with another CC. Some models have 2 blades and others have 3 for the same deck size. What are the pros and cons of each blade count?

BTW, the reason I may go with another CC is that the JD & Craftsman have levers on each rear fender that my hips bump into when getting off, while the CC has no lever on the left side. No on Husky's due to high repair record. My CC was trouble free until this year when the drive belt broke. Also had a crack in the deck that got welded. Not bad for 12 years.

 

[4get gto]

Normally the wider the deck the more blades. Curious myself as to why they would make a same size deck with either 2 or 3.
I have a couple older Sears / Roper garden tractors but one is a 38" 2 blade cut and other is a 42" 3 blade. Which makes sense. Maybe they advertise their decks as doing different tasks?

 

[2458n]

Save money by having fewer spindles.

 

[BoylermanCT]

Theoretically a deck with 2 blades will have faster tip speed than the same deck with 3 blades since the blades are longer. Faster tip speed gives you better quality. I have a 46" deck with 2 blades which I think is the largest 2 blade deck. All the decks 48" and higher that I have seen have 3 blades. I also agree that fewer spindles and blades is cheaper to run.

 

[tomplum]

Tip speed is regulated via the pulley size. A 46" 2 blade may run with more vibration than a 46" 3 blade as the blade balance changes. With that being said, generally there are fewer quality of cut issues with a 2 blade- especially if you stretch its capabilities by cutting long grass or mulching. Bagging becomes a different animal with a 3 blades. A premium 3 blade unit will require a powerflo type assist where as a basic 3 blade is sold without. On a Cub, I would get a 2 blade.

 

[Pilot]

Thanks for the replies, but it is a moot point now--I bought a 3 blade JD. Turns out my memory was wrong about the handles on each side. Stopped by HD today & they had some good prices on returned mowers. JD D155, 48 inch deck, handle on only one fender, got for $1,484, or 1/3 off list when including my military discount. MSRP of $2,200; I just couldn't walk away.

My 12 yr. old CC will go on Craigslist when I replace a bent blade (hit a rock) in a couple days.

 

[dragoneggs]

Tip speed is regulated via the pulley size. A 46" 2 blade may run with more vibration than a 46" 3 blade as the blade balance changes. With that being said, generally there are fewer quality of cut issues with a 2 blade- especially if you stretch its capabilities by cutting long grass or mulching. Bagging becomes a different animal with a 3 blades. A premium 3 blade unit will require a powerflo type assist where as a basic 3 blade is sold without. On a Cub, I would get a 2 blade.

Yes pulley size can regulate tip speed but for same pulley/spindle rpm the longer blade typical of a two blade setup would have a higher tip speed. I have found a two blade at 42in wide cut is ideal for me. Of course I only mow an acre but the relatively small width is good for uneven ground as well as tight spaces.

 

[Spanner]

Tom is correct here. The manufacturers adapt the pulley diameter to regulate the blade RPM's compared to Engine Speed/RPM.

For a given width the number of spindles is determined by the limiting dimension of "Wheelbase". You need a longer wheelbase for a longer blade when mounting the blades between the front & rear wheels. So for a wider 'cut' you need more MMM spindles/blades rather than fewer/longer blades.

Trailed mowers are a different story...