Hey, I've tried both Webb manual cylinder mowers, both give the washboard effect. Not enough blades or spindle speed.

I did find one that might suit, although I don't see it on their site anymore, called a Perfecta by RT Machinery. I think the cost was around £125 the last time I asked. Give them a call, they may have it still. https://rtmachinery.co.uk/

 

Thanks @RCUK . I will keep that in mind.

I'm still waiting for other recommendations, preferably based on your personal experience. US folks can answer too of course, just might be more difficult to get that equipment here in Europe. I'm open for all kind of suggestions.

 

Does it make any difference to the washboarding effect if you push very fast? I'm not too familiar with using a manual sorry.

https://www.amazon.co.uk/dp/B083X3ZBDK/?coliid=I1UO7NR9SLPRW9&colid=27JPR04FV6I4W&psc=1&ref_=lv_ov_lig_dp_it

I have a small sloped lawn so I use this battery powered Einhell for ease of use and I don't get any washboarding effect. It cuts real clean as long as I pay attention to checking the reel to bedknife regularly. I think the reel speed with the battery power is better suited to the lower HOCs. It cuts best at 14mm (0.55in), its lowest setting. I mostly used it at 23mm last season and had results that I personally was very satisfied with. I used it at 32 and 39mm and was less satisfied because it left more uncut blades of grass/stragglers. I mention it on page 6 of my journal. I mention the 14mm cut on page 7.
I understand that you asked about a manual reel mower but I thought I'd share my experience anyway, hope it helps.

 

For a manual reel mower where the reel is driven by the wheels, the frequency of clip is the same for different walking speeds. If you walk 10ft and the drive wheels spin 5 rotations, the reel will spin lets say 20 times. With 5 blades, that's 100 cuts in 10ft or one cut every 1.2in. The walking speed doesn't factor in.

I use a 7 blade Earthwise with a custom rear roller at 0.75in HOC. I only occassionally see washboarding at that height. I suspect it would washboard at 0.5in. Mclane makes or used to make a 10 blade manual reel mower that could work at 0.5in but I have no personal experience with it. I'd like to get one, but they're hard to find.

For reference, the frequency of clip on my Earthwise is about one cut every 1in. To cut ok at 0.5in, I think you need something with a frequency of clip at ~0.7in or smaller. The Mclane looks like it is 0.67in (8in drive wheels, 10 blades, and 30 to 8 gear ratio).

 

@Mark B , thanks, but walking speed does not matter as @frostyshake just described. I actually do not get washboarding at 24mm (around 1 inch), but the thing is that I like my grass cut at 0.5 inches. I will have a look at your journal regarding the Einhell, 14mm sounds good to me, thanks

@frostyshake thanks! I will have a look at those products as well. 0.75 is a bit higher what I'd like but better than washboarding at 0.5 . I will also have a look at the McLane. Also thanks for the clip frequency lesson.