I haven’t posted much on this frame so i’ll elaborate a bit on it now that it’s done.
I have always wanted an “All-rounder” or “monster-cross” frame. I know some people cringe at seeing the word “monstercross” since it’s what some people use to describe a 29er with drop bars, but not sure why or if there’s a negative connotation. When you are using cyclocross frame geometry and tube sizes (thinner diameter and wall-thickness) but adding the ability to run fatter tires (1.8″ or even over 2″ wide MTB tires), and disc brakes, then it truly is a monstercross and not a mountain bike. A 29er with drop bars is the Salsa Fargo or even a Karate Monkey. The Fargo is a different story and it is a true mountain bike that just happens to come with drop bars. This year’s model especially since it changed its fork dimensions to be suspension adjusted (you can swap the rigid it comes with for an 80mm suspension fork).
What I was going after with my latest build was more akin to bikes I have coveted but never owned — a Rivendell Atlantis or the old All-Rounder, sans lugs. However, because I am a gorilla and wanted different dimensions that I knew worked for me, I used the outline of an Independent Fabrications 56cm Planet Cross bike (when they did stock geometry) but made it with disc brakes and able to fit 700 x 55c tires (up to 2.2″ 29er tires). I have 135mm rear axle spacing (MTB instead of road hubs); the head tube/seat tube angles are 71.5/72, 425mm chainstays; 56mm seat tube center to center; and the top tube is 59.5cm. I used a 68mm BB shell to make it more cross-like but added a wishbone seat stay to make it more MTB-like. The fork has a lugged crown with raked-legs and can fit a tire even up to 2.4″! It’s a bit over the top but when you go lugged you take what they give you (there aren’t many options for lugged fork crowns for this type of bike – it’s really just a lugged MTB fork crown). Anyways, the bike has the same fork rake as my IF cross fork (45mm) and a trail figure just a bit more than the old cross bike = 70mm. My old IF has about 64mm of trail but for a Monstercross I thought it best to add more trail since it’ll be used differently than a dedicated cross bike.
I used mostly True Temper tubes for this frame – a 37 x 167mm head tube for a fork with a 1-1/8″ steerer tube, 28.6mm top tube, 31.8 down tube, 28.6 externally butted seat tube, and some nice single bend beefy chainstays. The wishbone seat stay I made from 4130 steel — 22mm tube from the seat tube, stepping down to 19mm for the ‘crown’, then going to 14mm x 0.09mm straight gauge for the legs.
I used the low-mount Naked Boomerang plate dropouts (disc tab on chainstay) which have one eyelet for fenders or a rack. These are nice dropouts that are cheaper than the Paragon low-mount dropouts by quite a bit, but they are way more manual to finish. You have to tap threads into the derailleur hanger as well as for the eyelets. They come pre-drilled but it’s a bit of extra work. They also come with or without stainless steel plates that seem mostly for the bling factor but also protection of the dropout where it gets trashed the most (axle slot, disc mount holes, and eyelet). Overall, I like these dropouts a lot, but I will probably get the ones withOUT the stainless plates next time just to make it easier on me. They are pretty heavy enough as is. I’m not going to present a bike at NAHBS anytime soon. All said and done, frame weighs in at 4.6lbs.