Mower comparison: sickle bar, flail and rotary

[Maine Hills]

We have a BCS 749 with a 59" BCS duplex sickle bar mower, a 32" Berta flail mower and a 32" BCS/Del Morino brush mower which are used to mow a former pasture and a wild blueberry field. Most of the fields are mowed once a year. The wild blueberry fields are mowed every other year. I spread the mowing over the second half of the summer. During hot weather I mow in the late afternoon or evening when the sun is low and the air has cooled. 3 mph is possible for mowing short grass on smooth level ground but my speed is usually considerably slower. Locking the differential is helps keep the mower headed straight when mowing across steep hills.

The BCS sickle bar mower is used as primary mower for parts of our fields which are too steep for me to mow with a four wheel tractor and rotary cutter. Most of the fields are mowed once a year and the grass an thin wood plants can be six feet tall. The skids are set for about four inch tall cut. The fields have lots of large rocks and the sickle bar rides over the rocks with no problems. The cut grass can take a couple of months to decay after cutting but that has not caused any problems. Occasionally the sickle bar mower will push tall cut grass along for a while and then leave of large clump. Cutting large areas with second year Burdock or other thorny plants which tend to stick together was not satisfactory with the sickle bar mower. It will cut the stems but the plants will remain standing and just be pushed along until no more progress is possible. Individual plants are not a problem. The sickle bar mower initially tended to ride up when going up steep inclines or over large lumps and bumps. This was eliminated by adding a PTO extension and a mower. I mow with the engine at half to two-thirds throttle. Second gear is used for most areas but first gear is used on steep slopes or in tight areas.

The Berta flail mower has several uses. The wild blueberry field need to be cut close very close to the ground every other year and flail mowers are the standard mower for that use. The roller is set for about a half inch cut. The flail mower is also used to mow around the edges of the lawn where it provides a satisfactory cut, though perhaps not quite suitable for a garden club tour. The flail mower is fantastic at mulching, and is used to mow and mulch flower beds in the fall. We also use it to mulch cuttings from bushes, particularly thorny bushes - lay the cuttings on the ground and mower over them with the flail mower. Another use is cutting the bottom of a wide drainage ditch. The flail makes noise when a rock is encountered, and very occasionally a small rock will be ejected out the front of the mower. The flail mower sometimes bogs down and then clogs on grass over three feet tall so it is not satisfactory as the primary mower for tall grass. Second year Burdock stems will wind around the drum and stall the mower. Full throttle is usually used and most mowing with the flail mower is done with the tractor in first gear. We purchased the accessory front wheels with the mower but took them off after the first season and haven't reinstalled them.

The BCS/Del Morino rotary cutter is used for thick brush and anything which will clog the flail mower and which we don't want to mow with the sickle bar mower. It will handle clumps of second year burdock and pretty much anything it can push over. Thick stems will sometimes bend over and the mower will ride over them. In those instances I have found backing over the stems with the mower down and cutting, and then going forward a second time will usually cut the stems into sufficiently small pieces. However the rotary cutter does not do close to the amount of mulching which the flail mower does. Full throttle is usually used and most mowing with the flail mower is done with the tractor in first gear. We purchased the rotary cutter after finding there were situations, particularly mowing second year Burdock, where neither the sickle bar mower nor the flail mower was not satisfactory. It's become the first choice for clearing brush in areas inaccessible to our four wheel tractor and brush cutter.

 

[Freep]

Great post - very helpful. I am looking to purchase a BCS 853 and a mower. I am leaning toward a flail mower, but am not yet fully decided. I had not considered a sickle mower, however I have access to BCS 720, which can run a reasonable size sickle bar mower (other mowers not really an option). So I am at least considered the possibility now.

How tall does your grass need to be before the sickle bar mower can do a decent job cutting it? I have heard that sickle bars perform poorly with short-ish grass.

 

[Maine Hills]

Our sickle bar mower height is set at about four inches. I know it doesn't do well on grass that is only a few inches taller than the mower, but have not experimented to determine the minimum grass height necessary for a satisfactory cut. My guess is if the sickle bar mower was closer to the ground it would do better on shorter grass because the grass would bend less.

In many respects our flail mower is the best all around mower as long as the grass is not over three feet in height.

 

[Freep]

I'm not positive, but I think I could manage to limit my neglect to 30 inches. I'll bet that sickle mower is great for people with grass-eating livestock.

 

[Egon]

Sickle bar's must be kept sharp & properly set up. No slop on the ledger plates. Some grasses cut much harder than others.

The number of cutting actions per minute must be correlated to ground speed.

 

[leonz]

Helllo Freep, Egon is correct in what he has told you.

About your beautiful flail mower, you should reinstall your front caster wheels and use them. The other thing is you should be taking half cuts with the flail mower if you leave the brush that tall.

If you invest in a wet well grinder for your flail mower knives from micromark $99.00-the last time I checked and the angle setter from woodcraft $25+- you will be able to to sharpen the flail mower knives and they will cut very well all the time every time. The cutting edge angle should be about 37 degrees so you can set the grinders tool bed at that angle. If you can sharpen the knife edges on the sickle knives great the wet well grinder will work well for that too and not lose the knife temper as it cool grinds all metals on a low speed wheel.

 

[Maine Hills]

The sickle bar cutters are sharp. The BCS duplex sickle bar mowers has springs which keep the bars together. I have not had any problems with the blades not sharp enough nor with not enough pressure on the blades.

So far I've been satisfied with the flail mower without the caster wheels. I'll probably reinstall them this summer and experiment.

Taking half or less width cuts with the flail mower in very tall grass does not solve the problem of the grass wrapping around the drum which I've had occasionally.

 

[CodeMonkey]

Tried a BCS 30" sickle bar this morning thinking it would be faster than the flail.

It is if I put the tractor in second gear, but I have a hard time keeping up with it - especially on uneven ground. Also, on rough terrain, because of the light weight of the mower, the bar bounces up and I miss areas.

The end result is that I went back to the flail mower - I can keep up with it in first gear and it mulches what I am cutting.

 

[jcraftenworth]

There's something very satisfying about running a rototiller and a flail mower and seeing the soil or plant matter pulverized into smooth tiny pieces!!!

 

[Maine Hills]

Bump since it is prime equipment buying time.