I bought a FX3 last year and have been riding mainly on the paved roads locally. While the original tires were 32mm it seemed I could feel every rock of the chip seal. Recently put WTB Nano 40mm (700c) on and what a difference. The gravel (kind of large gravel) roads are actually nice to ride on. Where I didn't like to go much over 12mph or so (vibration) with the fatter tires 20 on a downhill isn't that bad. I really didn't play with the air pressure on the stock Bontrager tires because they already felt a bit sluggish. There are a lot of dirt roads and two track near the house that need exploring! Best get on it!

WTB Nanos are good tires, and the 700x40 size is great for a lot of hybrids. I'll bet they just barely fit in an FX frame! I ride a similar tire (Vittoria Mezcal) in a 27.5x2.1 size and run about 25 psi front and 35 psi rear. Gravel and dirt riding is sublime at these pressures -- welcome to the wide tire club!

While I did not measure the clearance, it looks to be 5mm on the front and quite a bit in back. Except one spot where they have what looks to be a tab sticking straight out for fenders? That one is pretty tight, 'bout 3mm. I saw no use for it so I filed it down till I had enough clearance to easily install the rear wheel.

Yes, that's a fender tab, and you can definitely modify it for easier tire mounting if you like. It's nice that frames are being designed for larger rubber these days.

I have WTB Nano 40mm, tubeless tires on my Focus Mares CX bike (Stan’s Grail tubeless rims) Yes, they fit, with room for mud...I also like them a great deal.

I am about 5’8” tall, 160lbs. I may be running my tires with too much pressure. I believe the “suggested” range is 30-45 lbs. I have been running the bottom range. I know many ignore the suggested range. I am not above disregarding these limits, either. I would like to have some idea about “how low to go” though?

I'm running tubes on mine, older style I guess but they were cheap enough to 'speriment. I'm at 50-55 psi but I might try a bit lower.

This thread is making me want to put WTB Nanos on my Roam >_<

The 40mm ones will fit with tons of room to spare. Heck, even the 29x2.1s fit! They're tight, but they fit.

I got a used MTB last Sept. & the previous owner put those on. I quickly moved them to a hybrid I have, but then hung the bike up w/o riding it. but the one ride I used them on, on the MTB, with Wifey, on a paved trail, they were nice, at near max pressure (rear). I like 2.25" WTB Riddlers on that MTB bike now cuz I ride it off road. good brand!

looking forward to a casual ride w Wifey on the Nanos sometime this summer maybe

the previous owner of that MTB said he got the Nanos to go fast in the woods!

I believe they are the 40mm model