Hey folks, I have a couple questions about switching to a rigid fork.
I currently ride a 2010 Marin Bobcat Trail, which I like pretty well other than the fork. It has a super heavy Suntour XCM, which works well enough but weighs a ton. I am pretty well decided on going back to a rigid setup, but having a hard time deciding which fork. I have been looking at Surly, Kona, and Salsa because I would like a steel fork to keep cost down. The axle to crown on my fork is published as 486mm, and I measured it at 18.75 in, or 476mm... most forks for 26" wheels are between ~400 and ~460. Should I be looking at 29er forks, or just go with something a little shorter?

476mm a/c = 100mm travel 26"

Your suspension forks should have about 25% sag when you're riding it.

When your fork is set at 25% sag it will have a a/c measurement of about 450mm

Something like a 100mm Surly 1x1 with 453mm a/c or a Surly Instigator 1.0 with 447mm a/c is what you want.

https://surlybikes.com/parts/forks/1x1_fork
https://surlybikes.com/parts/forks/instigator_fork

Sweet, that's exactly what I needed to know. Thanks!

Nashbar sells some attractively priced rigid forks-- or you could e-fleece (er, ebay) a better fork from Fox or Rock Shox.
A 10 year old Float, SID or Reba can be had for pennies on the dollar and will be many times superior than your old fork