some things to think about. when trying to size a finishing mower.....
belts on a finishing mower. only grip so much. before they start slipping and you start tearing up belts left and right.
if you have any hills that you need to mow up. extra HP / torque is needed to be put to the wheels.
personally hate riding lawn mowers and garden size riding lawn mower tractors. due to time you get off of them your entire body has the jingles. vs a larger tractor were vibrations are down to a min. and its like getting out of a car or truck.
how wet the grass is, and how tall and thick the grass is, can make a huge difference on how fast you can go (ground speed) along with how short you are trying to cut the grass/weeds down to.
if you can get a good belt with good grip on pulleys, and engine can put out the torque and RPMs. a higher ground speed can be achieved to a point.
there are some cheap belts and then there are some good quality and normally more expensive belts. that can withstand higher temperatures, and do not stretch nearly as much as other lower quality belts as the belts heat up.
having the belt set to the correct tension, (not to loose, not to tight) for the finishing mower can make a difference between a belt slipping, or a blade getting caught up with grass/weeds and no longer spins resulting you cleaning things out from under deck.
different type of blades on a finishing mower can make a difference as well. as far as how fast you can go (ground speed) you have mulching blades, that have a pretty good twist in the blades, then you have the regular blades that have some twisting in the blade. then straight blades with no twisting in them. the mulching blades are going to cause lower ground speed, and the straight blades can allow higher ground speed.
also how the grass shoots out from the deck can make a big difference. you have some decks with just a single side all grass goes out of, then you have decks were grass can come out of both sides, and then decks that really do not have any sort of back on them, and grass goes out the back. the longer grass stays under the deck, more HP you will need and slower ground speed will most likely happen. the quicker the grass exits the deck the less HP and higher ground speed achieved.
blade cutting edge. can make a difference in how fast you can go. extremely dull blade will cause more torque loss. due to blade has to bang the blade of grass. vs cutting the blade of grass.
keeping things greased and lubricated. can make a difference as well. i know i can tell a difference between i forgot to grease. when using the old allics chalmers CA with wood belly mower under it. then going to shed to grease the spindles up on the finishing mower and going right back to mowing. it may not be much. but there is a difference.
your RPMs will most likely stay the same across all finishing mower decks. but the torque from engine will differ from tractor to tractor and how the torque from engine is transferred to finishing mower and to the drive wheels of the tractor.
=============
the faster i can mow (higher ground speed) the better for me. but also wider the deck i can get the better for me. or should i say there is a sweet spot among the 2.
============
on a side note why is it, that finishing mowers, are not driven by chains and sprockets vs pulleys and belts?
