Seat post question: road vs mtb...what's the diff?

mds2076 said:

I have to replace the seat post on my newly acquired Trek Y22 mountain bike. It's the usual Trek/Bontrager 27.2mm diam. Question is, looking on Ebay, some seat posts are sold for road bikes. What is the difference between road and mtb seat posts? I'm looking at a Bontrager Race Lite...how do I know if I can use it? The diameter is right so would fit in the frame ok. Is it something to do with the saddle clamping arrangement that differentiates between road & mtb. Or is there in fact no difference at all?

I've got an oversize Ritchey mtb post on my Litespeed road bike. It's all good.

mds2076 said:

I have to replace the seat post on my newly acquired Trek Y22 mountain bike. It's the usual Trek/Bontrager 27.2mm diam. Question is, looking on Ebay, some seat posts are sold for road bikes. What is the difference between road and mtb seat posts? I'm looking at a Bontrager Race Lite...how do

I think it's a guideline for length. Rarely you'll see a MTB post that's under 300mm, and normally at 350mm (ie. see Nashbar's version of their Road and MTB seatposts at the same price). Road seems to imply around 250mm of post. Sometimes you need that extra length, like on a compact frame for a person on the tall end of their recommend height chart.

mds2076 said:

I have to replace the seat post on my newly acquired Trek Y22 mountain bike. It's the usual Trek/Bontrager 27.2mm diam. Question is, looking on Ebay, some seat posts are sold for road bikes. What is the difference between road and mtb seat posts? I'm looking at a Bontrager Race Lite...how do I know if I can use it? The diameter is right so would fit in the frame ok. Is it something to do with the saddle clamping arrangement that differentiates between road & mtb. Or is there in fact no difference at all?

Road seatposts sometimes will have zero setback and MTB seatposts can have an exaggerated setback to get you over the rear wheels better. Most of them are the same though.

Mostly length. Looking at mine, I believe it's just a bit thicker, too, in deference to the greater pounding it will take.

Hey, I have a Y22 myself. Not a bad bike, especially given the prices they sell for today.

One recommendation, if you don't already have this - get on ebay and get a locking shock for it. I have an XC Pro with remote, though one with the locker on the shock will do. These days, I pretty much leave it locked except for the fast downhills, where the rear susp. makes a big difference. Just putting on an air shock will knock 1/2 pound off of the bike.

All seat posts come in different diameters... I always thought just as the other posters that a Mtn. and road post are the same... EXCEPT a mountian post is longer. That said you can buy road specific posts that are longer so I don't know for sure. Maybe the finish is more aero on a road, and more dirt repelling on the Mtn 😉 .