I want fenders for my bike with 700x42 tires, but so far the only ones I've found that might fit are SKS Bluemels in 53mm size. Any other options out there I should consider? Most of the fenders I'm finding in this width are for 26".

Planet Bike's Cascadia 29er is another option. I've used both companies products, I think the SKS fenders are slightly prettier, but the PB fenders come with slightly better flaps.

ran a 40 with a mudguard not much wider than the tire, no problems ..
I have a bit of clearance over the tire, .. water tends to sling off the center of the tire anyhow..

You got the Aluminum boutique mudguards too , you know..

For 2014, SKS merged the P-series and Longboard series fenders into one line, the P-series Longboards.

They're available in widths of 35, 45, 50, 55 and 65 mm, all for 700C.

On my disc-brake, studded tire commuter I replaced my old, Euro-spec P-series (like the older US-spec P-series, but with a mudflap in front and a reflector in the back) with a new P-45 Longboards. The longer main coverage and longer mudflap are both very nice. My BB, crankset, and drivetrain have never been cleaner. On the front, I used to get blowback from the front of the fender to the headlight. With the new longer one, not any more!

Once upon a time I had Cascadias. My beef with them was that they cut the fender shorter before adding the mudflap. The overall length of the Cascadia fender and mudflap was less than the SKS P-Series WITHOT the mudflap. They also rattled something fierce.

I've got SKS p-50s on tires that size. Work great.

Civia has some fenders that will work. I got a set of Wirth's off eBay that just cleared a set of 40mm knobbies.

These are 60mm wide Planet Bike 26" ATB fenders over 700 X 35's and I had to pull them in a hair to close up the gaps at the ends of the fenders:



I bought them for my Winter bike but didn't like how they fit on it, too much space between the tire and fenders so on a whim I tried them on my 700c hybrid. I'm pretty happy with the fit, now if I could just find fenders to fit my 26 inch wheels like this. I put Cascadias on my Winter bike and they fit pretty well but not this well.

Berthoud has some really nice 700x60 that would work great for this application

I like those P Long boards.... Looks like 50mm should definitely work. The Planet Bike Cascadia 29 I won't have clearance for. I run 42mm tires, but I have a hybrid. I know I can fit 50mm Big Apples, but 55 would be questionable and may interfere with my front derailleur.

Although looking at my bike again, I might need to use P clamps to attach the back fender since my frame only has one set of eyelets and it's taken by the rack. The dry season here goes from about April/May until December so I'm thinking I'll only have the fenders on during the rainy season and it'll be easier to not have to mess with the rack.

they will be fine in the one hole. Just mount the fender stays outboard, as they carry no weight. Might need a washer or two.

I have disc brakes so the my rack is the kind that has a 1" spacer built into the end of the legs. Also easier to not mess with the rack when I go to take the fenders off at the end of the wet season.

Fender stays bend. What you want to do is no problem to a competent installer. Might require a different bolt, but easy, and far superior to using clamps.

The only way I can even think of doing this is to put the fender stays in between the rack and frame; or getting a 1.5" long M5 bolt, putting two nuts on the bolt so that they lock in place and then threading that into the leg to hold the rack and then attaching the fender to the part of the bolt that extends out of the leg. Do you have soemthing else in mind?

Without having seen your bike, your rack, or your fenders, I'd put the stays between the rack (and I suppose the spacer) and the frame. Initial fitting might require removing the rack, might not. Removal and refitting wouldn't, just fix or unfix one side at a time. Some fender stays will want a washer between the rack and the stay, some won't. This is something that shops that fit fenders see all the time. Easy to deal with.

SKS also has a fender called Velo 55 for 29er types. They provide really good coverage with minimal hardware and come off in a snap.
Velo Orange also has their Zeppelin fenders in 52mm, I've used them as well.


Marc

For the front,just get a longer bolt and spacer for the left,and bend the stay:


Out back,replace the left rack bolt with a longer one,put the stay on the outside of the rack,and bend the stay. QED