I think my WTB Rocket-V Team has Ti rails. I've never had any issues either. I've actually had that saddle on every bike since the XLT. 5yrs old now and still kickin.
Scrub: Observation...it kinda looks like you run your frames on the bigger side vs me on the smaller side. (prob. just the appearance) Your bar height is always really low and your seat super forward. Mine's just the opposite. I love a really tall bar and my saddle is usually pretty far back.
How do you get your freakin' bikes so light, man?
What wheelset are you running on the RX? Is the Totem a solo air?
Nope, opposite. Small frames. I like being forward, getting more over the front of the bike. This lets me do that. I'm 5'9" with average arms and legs, but a short torso, so it works. Every time I've tried longer frames, even with short stems, it always feels off/too stretched out. Still lets me get to the back of the bike, and move it around a lot under me. Gives me the "in the bike" feel that I like vs. the "on the bike" just along for the ride.
Lots of ti and alu bolts and do dads. Serious. Got a huge load for super cheap years ago at Denver Veloswap, and it's been an addiction since. They just move along from frame to frame, I get new ones when something needs a funky size. Use them smartly, lots of anti-seize or grease as needed, don't over-torque, and it's all good. Alu for low torque and low-load bearing things, ti for the big stuff. Some stuff I leave steel - like any stem with m5 face plat bolts, stuff that gets loaded funny sideways, like the Reverb clamp bolts.
Got my admit settled, so here we go. A run down.
Small RX frame. Ti upper shock mount bolt. Running a high volume air can Rock Shox Monarch RT-AM, upper bushing swapped to RWC needle bearing setup. Smooooooothe. If out west, I'd maybe go back to a larger piggy-back shock, but around here, the smaller shock works great, particularly the higher volume can. The rear Maxle has been swapped out for a hadley alu thru-bolt from a 150mm rear end bike. Lopped off the old trheads, re-threaded to the Maxle interface. Lighter, stiffer, doesn't loosen up, less crap sticking out off the bike to break off. Alu h2o bolts. Salsa seat clamp with an alu bolt. Works Components -1* headset, Cane Creek bearings, alu crown race. No top bearing cap, no spacers below the stem. Run the stem right on top of the upper compression bits above the bearing. Been doing that for a few years, no issues. So long as you aren't a bone-head with a pressure washer, no problem. Alu bolt for the top cap.
Totem Solo Air. Bone stock. A half pound lighter than the same size Domain, found for only a bit more than I paid for the Domain. Will sell the Domain off to help offest the cost. Running a Boxxer Maxle. Same spacing, fits and works beautifully - like the rear, just less crap sticking out this way.
Race Face bar cut down toe 29.5" (to match the other bikes), Rogue grips, Truvativ Stylo Race 60mm stem. Fairly light, not super spendy, stiff, strong enough for my riding. The Stylo and AKA series of stems are total sleepers. Not blingy, but light, stiff, strong, and cheap. Reverb post. SLR vanox seat. No problem with rails. I've had many vanox and ti rail seats over the years without issue. Buy 'em used on ebay for way less than retail when some road wanker sells them off because the covers get worn. When bad enough, they are very easy to re-upholster.
Front wheel is the stocker off the Pitch I had a few years back. It's actually pretty light. Stiff. Specialized house brand stuff, but nice bearings, alu nipples. Tube ina Minion DHF EXO/3C. Huge chunk less weight than the DH version, but still a damn tough tire, works great up front. Awesome chunk tire.
Rear is a Hope ProII hub/Mavic 317 rim combo, alu nips. Tubeless with a Specialized 2.2 UST something. It's working well, is still a tough sidewall, but not full on DH tire heavy. Rolls fast, has huge volume, and I like it considerably more than the Minion DHR dual ply DH tire it replaced.
Elixir-R front brake, 203mm. XX rear, 160mm ( bought pusposefully so it would be compatible with the Reverb remote. Ti rotor and caliper mount bolts. Alu lever and body bolts. Matchmaker clamps to connect them to the rear shifter and Reverb remote. Less clutter on the bars, ever so slightly less weight.
X.9 10 speed shifter and short cage rear mech. Ti cable clamp bolt, alu limit and b-tension bolts. SRAM 10 speed something chain, Shimano XT 11-36 10 speed cassette.
LX 170mm crank. 31t Homebrewed Components ring. Alu ring bolts. Ti non-drive side crank bolts. Straitline Silent guide - this thing rocks! Stupid light for what it is, and super simple. No moving parts. Works beautifully. Steel bolts for the ISCG mount. Wheels Manufacturing BB cups. XT pedals.
It all adds up to a lighter ride. Lots bought on sale, much moved from bike to bike over the years, so it's not as if I just shelled out all the dough in one go for this. LX cranks just the arms are only a few grams heavier than XT for a hell of a lot less money. If you're going to run other than the stock rings anyhow, and already have the lighter bolts, then why spend more? Cables/hoses/chain run short as I can go, just a little extra so as not to tear things out in a wreck. "Pinner" tires, particularly now with tubeless - I can get away with less tire, and not DH tires and not worry about.
I'm not a big guy, try to ride with finesse vs. like a bowling ball, and don't go stupid big on my air moves. All means I can get away with light builds that larger mammals would play well with.