The number of blades on the reel, along with the reel diameter significantly influence the maximum possible mowing height. The further apart the blades are, the taller grass can be theoretically mowed by the reel. The more the blades, the more does the mower lose the ability to mow taller grass, because the space between individual blades is smaller. Thus, only shorter grass blades will manage to get into the reel.
The maximum mowing height of a self-propelled reel mower is usually between 8 and 10 mm. Nothing very different is practically possible because of the front roller. It drives before the reel and lays individual grass blades down so that they can rise again and can be trimmed by the reel. Taller grass would not be able to rise and the mower would ride over it.
The number of blades also influences the cutting frequency, which is a key parameter of reel mowers. This frequency indicates how many times the blades of the reel can cut within one meter. For example, a 10-blade reel and a low number of revs can mow worse than a 5-blade reel with a high number of revs. The revs must be set up so that they ensure a high-quality cut, but without unnecessary damage to the blades due to overly high rev count. This influences the longevity of the reel and a possible number of sharpenings. High revs also usually cause more reel noise.