I just took delivery of some new mudguards for my Elephant NFE.
In February I had installed some "SimWorks by Honjo Turtle 58" mudguards on my Elephant NFE. These hammered aluminium mudguards were the only ones wide enough for my 42 mm 650B tyres that I could find locally. They were absolutely beautiful, very classic looks, but it took a long time to get them to work because there was actually very little clearance between the rolled edges and the sides of the tyres. The front mudguard attaches to the bottom of the front rack, which turned out to be marginally off-centre and that exacerbated the problems. Even after many hours and repeated attempts there were times during a ride when I would hear what sounded like a tyre rubbing against the metal. I could never get it right.
Things improved a bit after I switched from Compass Babyshoe Pass EL tyres with tubes to Babyshoe Pass tubeless which seemed to give me a bit more space, but after persistent problems getting those tyres to seal and hold air as reliably as a tube, I switched back on the front wheel and again faced the clearance issues.
What this also means is that I didn't really have much margin in case any foreign object got wedged between the tyre and the mudguard. So I finally decided top ditch my "SimWorks by Honjo Turtle 58" (which would probably be fine with 38 mm tyres) and try something with more clearance.
Shintaro recommended the SKS mudguards, which are lightweight and very easy to fit.
I ordered some SKS Bluemels ("SKS ブルーメルス 65mm幅 26インチ×2.1-2.35 ドロヨケ") in silver. They're 65 mm wide MTB (26" inch, ETRTO 559) mudguards for tyres between 2.1 and 2.35" wide. Exterior diameter-wise they should work fine for 650B / 27.5" / ETRTO 584 wheels with 42 mm tyres which are very close in diameter to the wider 26" tyres.
The SKS Bluemels are constructed of thin strips of aluminium sandwiched between two layers of transparent plastic, with riveted mounting brackets. One nice feature is a safety release in the front struts that will let them disconnect if a foreign object gets caught between the tyre and the mudguard, rather than jamming the wheel, sending me over the handlebar.
I will have to see how well they'll work in the rain. They don't wrap around quite as much to the rear on the front wheel, so perhaps I will have to add a mud flap later.