Bike nerdery content. TL;DR at the bottom:

I've known for a while that the aftermarket fork I have on my 710 is shorter than the stock one and it's bugged me terribly ever since I installed it. I finally took the time to take the bike apart and get some actual measurements to figure out exactly how much of a difference there is.

Turns out my new fork axle-to-crown is 10mm shorter than the stock one. This results the front end lowering quite significantly, and steepening all the effective angles on the bike by a little over .5°. Not a huge issue on paper - the 63cm frame that I have was brazed at 73.5°/72.5° so the HTA/STA steepened up to 74°/73°. Still a reasonably shallow STA and that HTA is steep, but not overly so.

What bugged me is that with the front end 10mm lower there is a quite conspicuous downward slope to the top tube, which just looks so wrong on a classic lugged frame. It's been on my mind constantly and there has been handwringing upon handwringing with the different options to fix it:

I bought a needle bearing headset with a tall lower stack height, but that only gave me a few additional millimeters.
I could go back to the original fork but I never really liked how it rode (5cm trail with wide 650b tires just feels a little weird), plus I'd have to get canti posts brazed on and powdercoated. Handling gets even weirder with a handlebar bag.
I could have the original fork re-raked to lower the trail and get the handling I want, but that's another pretty big chunk of change and the front end would drop a bit anyways so I'm still in the same situation, just not as bad.
Custom forks are $$$ I'd rather use for something different.

I eventually stumbled upon someone on eBay that makes taller crown races for MTBs - I guess sometimes for fat bikes you need some extra room below the head tube so a suspension fork doesn't smack the downtube - but all he made were for forks with 1 1/8" or 1 1/2" steer tubes. I figured something like that would my best option - using a cartridge bearing headset with 36°/45° bearings all I had to do was reproduce the fairly simple geometry of the crown race that came with the headset I wanted to use and then add 10mm on the bottom!

Drew up something up real quick and shot it off to him since he does custom parts as well. $30 and a day later the part is on it's way to my house!

Fingers crossed I designed it correctly. Also got a nice little boost to the ego when he told me he'd do it for the same price as his stock spacers - "Very nice drawing will make it easy."

Although, now I'm going to have a bit of a challenge because I'm about 5mm shorter than ideal on steer tube length...

TL;DR - I'm getting a custom crown race spacer to make up for a 10mm too short axle to crown on one of my bikes.