Mountain bike idiot wants to build a cyclocross bike

[bxcc]

So who wants to school me in the ways of CX bikes? That's the short version. Now on to the long version.....

Here is my "wants" and "needs" lists. This should help folks understand what I'm looking for. It's going to be all over the place as I'm not sure where the priorities should lie. Any help in putting the build plan together would be greatly appreciated.

Needs:
A new bike for riding pavement (25%), gravel roads (60%), and light trails (15%). Most of the riding will be in and around Acadia National Park in Maine. Something comfortable but still efficient on the climbs that I can be on for the better part of a day. There’s no need for a bikepacking bike as I’ll never be too far away from civilization. Also, there will be no racing involved so no need to get all crazy on that end.

Wants:

Frame: I’m thinking I will go for another Waltly titanium frame so I can customize it to fit my purpose. Something along the lines of the OTSO Warakin. I’ve put roughly 100 miles on one of those and it was great. It was a 56cm and I think I’d like to go up to a 58cm. I’m just under 6 feet tall (maybe 182cm) and prefer a longer reach than most cramped road bikes offer.

Stem / bars: stem probably in the 70mm range. I don’t need mountain bike short but I don’t want a 100mm stem either. Bars probably 46mm wide.

Fork: Rockshox SID SL run at 80mm. It’s roughly 1350 grams and I could run it on the higher side so I’d only use 40mm or so. Most CX bikes have a tall head tube so I think I could drop that by 80mm to be around 100mm and that would keep the overall front end height the same. It could create a problem if I want to run a rigid fork though.

Seatpost: I’m liking the BikeYoke Divine SL on my single speed so I think I want to stick with that. It’s not much trouble to give the frame a 31.6 seat tube with a hole on the bottom for the cable. The Divine has a bit of cushion to it so I think that would be nice. The cushion is normal if it isn’t at it’s highest setting.

Drivetrain: Shimano GRX 1x set up. That would give me disc brakes and dropper lever capabilities.

Wheels / tires: I’ll do another Chinese carbon rim / DT Swiss 350 setup here. The tough part is deciding on what inner width and spoke count I should go with. What’s the consensus on a 21mm inner width rim with a 24 spoke 2 cross pattern build? I know it’s on the narrow side for current CX / gravel wheels but this will see more pavement than trail. This bring me to tire size and I’m not sure what size would be ideal. Maybe the 40mm range?? Would 21mm rims be sufficient for 38 to 42 mm tires? Keep in mind that I have the Ti single speed with 29x2.25 tires so I don’t need to go all trendy with big tires on this one.

So those are my thoughts on what I think I want. PLEASE let me know where I went wrong. I do not plan on ordering anything until spring so right now it’s only being built on paper.

As far as my capabilities, I've been riding mountain bikes since the early 90's and have built more bikes from scratch than I have purchased "off the shelf" bikes. So I'm good there. As for road / CX / gravel bikes, I'm completely new. I have ridden a few here and there, and the wife has a Trek Domane 6, but that's it.

[cst_jpr]

I'm a bit taller and 58cm frame is large for me. But that seems to be what osto recommends so if you just copy their geometry it should be good.
Waltly seems to be busy right now, so contact them as soon as you've decided to get a deposit in. Shipping price quoted was a lot higher than in the past ($150-300).

21mm inner 28mm outer is fine if you run 38 tires and never plan to go bigger, but I would consider 25/32mm.
Its a tradeoff of aero vs weight.

[tripleDot]

I'd recommend clearance for tire widths to be a few mm wider than your intended tire size. Gives you some room to mount at least fenders plus better mud clearance... even if you don't need them.

Rims, 20-21mm inner is sufficient. I have 2.25 slapped on my DT Swiss XR331 (i20) with no problems.

For my Waltly gravel bike, I had them put racks & fender mounts as I see myself doing some bikepacking. You might consider it if you want.

If you're gonna be on paved road most of the time, perhaps a rigid carbon fork might be more useful. With weight saving bonus.

[bxcc]

Thanks for the tips, that’s exactly what I was looking for.

I’m normally in the “wider is better” camp when it comes to rims but I also remember when 19mm inner was standard issue for 2.25 mountain bike tires. I just didn’t know if 21mm would be too narrow to be ideal. I’m trying to find the balance and not over do it as I have wider tire bikes if needed.

Fender and rack mounts are a good idea. I’m not sure I’ll ever use them but I can’t easily add them later.

I paid around $250 to ship my Waltly frame this past summer so I’ve added that to my budget already. Unfortunately I can’t commit to Waltly just yet as we have some major house projects coming up. Hopefully by spring I can get the ball rolling on the frame.

I have a rigid carbon fork from my first generic carbon SS build that’s 480mm and an 80mm SID is 485mm. I was thinking I could bounce between the two. Not sure if that’s ideal though and possibly taking the build in the wrong direction.

So you can probably see my issue. Finding the balance between a trail friendly road bike and a road friendly mountain bike. Being a mountain bike guy, I’m having a hard time keeping it road worthy.

[bxcc]

Just a little update. I've been working with Amy at Waltly to get this frame going. Currently, there is about an 8 week wait between placing the order and shipping the frame. So I'm trying to get this order placed soon. I have most of the geometry sorted and it's basically an Otso Warakin with a few changes. The geo is based off of a 480mm fork instead of 420mm and it has 30.9 seat post to open up dropper options.

I have the rims, spokes, and nipples on hand and I'm currently waiting for the hubs to arrive. They will have a slightly different look with 3k matte carbon Nextie rims (27mm outer, 22mm inner, 23mm depth), white DT Swiss Aerolite spokes, and pink double head nipples.

Now the big question is which frame design to choose. I love the retro twin top tube design of the first two options. The problem with this is that they either look REALLY good or REALLY bad. So do I go retro, or stick with the more modern style in the third picture?

[carbonazza]

Did you consider a classical CX frame format?
Like the Alan Super Cross carbon cyclocross but with Ti tubes instead.
I think this will age better( it did it already ) than the two pictured models.

[bxcc]

Are you talking about the lugged design or just the basic shape?

To be honest, I'm not completely sure what I'm looking for. I do know what I would like it to be somewhat different but still functional. I really like looking at the retro newsboy style bikes but not sure if I actually want to own one.

[carbonazza]

Are you talking about the lugged design or just the basic shape?

Just the basic shape, sorry for the confusion.

The dropped seatstays may fade one day.
While the rounded top tube is intriguing and original.
I feel I would get tired of the look after a while.

I would go for a classic shape for a Ti bike I plan to keep for long.
But ok, this is all very personal taste territory 

[bxcc]

Just the basic shape, sorry for the confusion.

The dropped seatstays may fade one day.
While the rounded top tube is intriguing and original.
I feel I would get tired of the look after a while.

I would go for a classic shape for a Ti bike I plan to keep for long.
But ok, this is all very personal taste territory 

Yup, it's definitely personal taste on the looks of the frame. I've just been looking at too many bike styles lately and figured I'd brainstorm out loud. 

[tripleDot]

I really like the curved top tube but not so much with it continuing into the seat stay. I personally love the Sklar's signature design.

https://www.sklarbikes.com/gravel-grinder-all-road-monstercross-bikes