justinzane

As a parallel to the discussion on seatposts and comfort, it is time to find out whether there really is a difference in comfort between various seatpost rail materials. To be clear, for a specific given saddle design, same top, same rail lengths, etc. and a specific rest-of-bike and rider and road; is there any significant difference in comfort between rail materials?

While rails are chosen frequently on the basis of affordability, of looks and of weight, for a given setup, does it really matter what rails you use. And, while there are a few anecdotal reviews out there (see below), are there any attempts at decent comparisons between rail types that are vaguely scientific?

- Glory Cycles Product Reviews: Carbon or Kium Rails - Is Carbon "RAILy" worth it? "As far as I could tell, the Carbon braided railed saddle has 2 major differences over the Kium. 1) There is WAY less vibration. ... 2) There is WAY less flex in the saddle. "

DrIsotope

I switched from a saddle with Cro-Mo rails to with one with 7x9 CF rails, and the difference was significant. Buzz and vibration were reduced dramatically. I was one who before thought that CF rails were just a weight weenie thing, but they really do change the performance characteristics of the saddle. Mine has a carbon-blend for the saddle base, and I also demo'd one with a full-carbon base. The full carbon was a lot stiffer, and a little less vibration-free. I think that the right amount of base flex combine with the right amount of rail flex makes for the most comfort, but everybody will find a different saddle to meet their needs-- there is no magic saddle out there. CF rails definitely help, though.

DMC707

Ti rails are the most comfortable, but also the most fragile for me --- i wasnt aware anyone made any aluminum rails

dr_lha

I recently swapped my saddle with CrMo rails with a practically identical saddle with Ti rails, and I noticed no difference. That said on my bike I don't find vibration to my ass to be a big issue. The Ti rail saddle weighed less though.

rpenmanparker 

I don't think there are any aluminum rails anymore. I broke them twice before I gave up on them back in the '80s. Bad, bad idea that has thankfully been abandoned. Aluminum is just too fatigue prone for that application.

Adrianinkc

I did a short ride on a carbon railed saddle today, didn't notice anything special but it was cold as hell so we will see tomorrow. Hopefully it doesn't snap before I can see a difference with my fat arse....

FeltF2Tarmac

My Fizik Kurve Snake saddle has aluminum rails but I think even these are now carbon.

PepeM

Main advantage is that the oval tubes are more aero.

exmechanic89

I've never noticed any difference between the Ti rails on bikes I've had, and steel. Never tried carbon though.

79pmooney

I raced an aluminum railed Selle Italia in the 70s. Loved that seat. It went a long way toward making a very steep angled Fuji Pro a great bike for me racing New England roads. It gave me no trouble at all but I let it on the Pro when I sold it. Figured if I kept riding it, it would break on me and I almost certainly went on to ride far more miles than the kid who bought the bike.

I now get ti railed seats (Terry Flys) for my good bikes, making sure to keep the seatpost clamps well away from the ends of the flat rail. (I broke one seat's rail when I had the clamp into the bend to get the setback I wanted. Now I also file a little round into the end of the clamps to further relieve stress there.)

Ben

oldbobcat

Before the breakup of the Soviet Union, when titanium was very expensive, several manufacturers made versions of their race saddles with aluminum rails. I plucked an alloy-railed Turbo, on sale. I quickly found out why. The rails bent a bit before completely breaking through at the clamp. Thankfully, nobody makes them anymore. (Fizik's "K:ium" is a Ti alloy.)

Actually, unless you're a real heavyweight (well over 200 lbs) or you're riding off-road without a suspension, titanium should work fine.

My rule of thumb is, steel if you're on a budget or you're a heavyweight, carbon fiber if you're a weight weenie and cost is no object, and titanium for the rest of us.

woodcraft

I have a saddle with carbon rails,

& they flex way more than steel- almost like having a sprung saddle.

The carbon saddle shell, however, is very stiff.

chaadster

Wow, I'm surprised to hear such certain opinions, because I've used Ti, steel (solid and tubular) and carbon railed saddles and can't say the rail material is evident in feel, and I'm usually pretty dialed-in to that kind of thing. Granted, I've only once had the same model with different rails-- San Marco Concor, steel and Ti-- and it was a long time ago; usually it's wholesale saddle swaps which bring the new rail material, so direct comparisons are almost impossible.

By the way, if anyone is interested in a 178gm carbon railed Oval saddle, shoot me a PM. I just replaced it with a Kium-railed Aliante R3.

Looigi

I've recently been riding Ti, Kium (?) and carbon rails. I have not noticed any differences attributable to the rails.

Jiggle

Carbon is so cheap I just get it all the time. I won't even look at a model that doesn't have carbon rails.

chaadster

https://www.amazon.com/Selle-SMP-Dyna.../dp/B00A7BPJLW

What up, ******! I'd love to roll that way, I guess-- I don't think rail material makes any meaningful difference outside weight savings-- but I can't spring the $300-$360 I'd need to kit out each of my bikes with an SMP Dynamic Carbon.

If you wanna throw one of them ****s my way, though, a brother would appreciate it!

popeye

Mine is just the opposite, stiff rails and flexy wings. I used to worry about
clamping down on those CF rails and never had a problem but I have had
two failures with tubular TI rails. Go figure.

Jiggle

Nah, I'd spend $150 tops. 99% of saddles are made in the same factory and only a sucker pays retail for them.

chaadster

SMP 4Bike line are in the 1%, handmade in their Italian factory. The do make saddles for other brands in another facility, but to get a 4Bike like the Dynamic, you have to get an SMP Dynamic, which are not available through discount outlets.

But what a bummer...the Specialized Romin Pro Carbon is out of reach for you, too, even though it's a whopping $160-some dollars less than SMP Dynamic CRB. Too bad.

slimyfrog

One for me One for you

Jiggle

It's called Black Friday sales, genius. I bet you are happy to pay $65 for Conti 4000 SII 'cause you found them for $5 off retail.

chaadster

I should hope it doesn't shock you to learn I don't ride Conti, nor do I wait for a once a year sale to buy saddles which are "so cheap" either.

Jiggle

I wouldn't buy an SMP but I like the Romin Pro Carbon. Browsing ebay I see they go for $130-$170 new and sell for around $100 slightly used. That's so cheap there's no reason to settle for less.

DrIsotope

If you can't tell the difference between a cro-mo rail and a CF rail (or even Ti and CF) I think you need to head down to the LBS to have your butt dyno retuned. Clearly it's out of adjustment.

chaadster

If you're willing to go wait around in the secondary market for a used one to pop up at the bottom end of the price scale in order to meet the "so cheap" requirement, clearly we have different definitions of "so cheap," to say nothing of divergent expectations.

Thanks for sharing your thoughts here; it's been a blast, and I've learned I can save a bundle with Geico!