MenuMenuModern Bike

30.9 mm Aluminum Bicycle Seatposts

The seatpost diameter must match to the seat tube diamater of your frame. If replacing a seatpost, you can usually find this measurement etched near the bottom of your current post.

SortSort

Showing 74 products:

Cane Creek Thudbuster ST G4 Suspension Seatpost - 30.9 x 375mm, 50mm, Black
Cane Creek Thudbuster ST G4 Suspension Seatpost - 30.9 x 375mm, 50mm, BlackCane Creek

Building on Thudbuster's proven parallel linkage technology Cane Creek has completely re-designed the seatpost for increased durability, a higher rider … read more

your price $199.99 + ships free

BuyBuyPART NUM 705891
Thomson Elite Covert Dropper Seatpost: 30.9 x 400mm 125mm Travel
Thomson Elite Covert Dropper Seatpost: 30.9 x 400mm 125mm TravelThomson

Item Specifications Length: 400 Diameter: 30.9 Travel: 125 Clamp Style: Std Rails … read more

$150 offretail $479.95 your price $329.95 + ships free

BuyBuyPART NUM 213345
Thomson Elite Seatpost Black 30.9 mm x 410 mm
Thomson Elite Seatpost Black 30.9 mm x 410 mmThomson

Over 40% stronger on ultimate strength test than the strongest production seatposts on the market. Over double the fatigue life of any other production … read more

StarStarStarStarStar 4.5 of 5 ( 4 ) 4.5 of 5 stars average ( 4 reviews )

your price $114.95 + ships free

BuyBuyPART NUM 972863
Thomson Elite Set Back Seatposts - Black - 30.9 x 410 mm
Thomson Elite Set Back Seatposts - Black - 30.9 x 410 mmThomson

The Elite Set Back Thomson Seatpost has a post and cradle which are machined from one piece of 7000 aluminum. Post and cradle are machined from one … read more

your price $114.95 + ships free

BuyBuyPART NUM 112698
Thomson Elite Seatpost Black 30.9 mm x 367 mm
Thomson Elite Seatpost Black 30.9 mm x 367 mmThomson

Over 40% stronger on ultimate strength test than the strongest production seatposts on the market. Over double the fatigue life of any other production … read more

StarStarStarStarStar 4.5 of 5 ( 4 ) 4.5 of 5 stars average ( 4 reviews )

your price $114.95 + ships free

BuyBuyPART NUM 503967
Thomson Elite Set Back Seatposts - Black - 30.9 x 367 mm
Thomson Elite Set Back Seatposts - Black - 30.9 x 367 mmThomson

The Elite Set Back Thomson Seatpost has a post and cradle which are machined from one piece of 7000 aluminum. Post and cradle are machined from one … read more

your price $114.95 + ships free

BuyBuyPART NUM 304886
Tranz-X Kitsuma Air Dropper Seatpost, 150mm, 30.9 x 455mm, Black
Tranz-X Kitsuma Air Dropper Seatpost, 150mm, 30.9 x 455mm, Black

Internal routing Lightweight alloy air cartridge adds rebound adjustment 7075 aluminum construction Upgraded internal bushings … read more

$17 offretail $185.00 your price $168.00 + ships free

BuyBuyPART NUM 576550
Thomson Masterpiece Seatposts Black
Thomson Masterpiece Seatposts BlackThomson

The Thomson Masterpiece Seatpost is not for everyone. We at Thomson wanted to create the best seatpost possible without regard to cost. The … read more

your price $159.95 + ships free

ChooseChoose
RaceFace Aeffect R Dropper Seatpost - 30.9 x 325mm, 100mm, Black
RaceFace Aeffect R Dropper Seatpost - 30.9 x 325mm, 100mm, Black

Introducing the Aeffect R Dropper Post. Yes it's budget friendly and a rock solid option for riders wanting a simple, trouble-free dropper post - but … read more

your price $214.99 + ships free

BuyBuyPART NUM 114574
Whisky No.7 Alloy Seatpost 30.9 x 400mm 0mm Offset Matte Black
Whisky No.7 Alloy Seatpost 30.9 x 400mm 0mm Offset Matte BlackWhisky Parts Co.

The No.7 Alloy seatposts are made to be durable, lightweight and comfortable. Whether you're remounting during the cross race, or abusing them on the … read more

your price $70.00 + ships free

BuyBuyPART NUM 789608
Whisky No.7 Alloy Seatpost 30.9 x 400mm 18mm Offset Matte Black
Whisky No.7 Alloy Seatpost 30.9 x 400mm 18mm Offset Matte BlackWhisky Parts Co.

The No.7 Alloy seatposts are made to be durable, lightweight and comfortable. Whether you're remounting during the cross race, or abusing them on the … read more

your price $70.00 + ships free

BuyBuyPART NUM 224035
RaceFace Aeffect R Dropper Seatpost - 30.9 x 465mm, 170mm, Black
RaceFace Aeffect R Dropper Seatpost - 30.9 x 465mm, 170mm, Black

Introducing the Aeffect R Dropper Post. Yes it's budget friendly and a rock solid option for riders wanting a simple, trouble-free dropper post - but … read more

your price $214.99 + ships free

BuyBuyPART NUM 234584
Dimension Two-Bolt Seatpost 30.9 x 350 Matte Black
Dimension Two-Bolt Seatpost 30.9 x 350 Matte BlackDimension

Dimension Two-Bolt Seatposts provide a sturdy and durable saddle perch for cross country and all-mountain riding in three diameters, rigorously tested … read more

your price $28.00

BuyBuyPART NUM 546168
Gusset Lofty XXL Seatpost, 30.9 X 450mm - Black
Gusset Lofty XXL Seatpost, 30.9 X 450mm - Black

Extra long forged 6061 aluminum post allowing maximum height adjustment 2-bolt micro-adjust clamp. 345g (27.2mm) Item Specifications … read more

your price $39.95 + ships free

BuyBuyPART NUM 150263
Ritchey Classic 2-Bolt Post, 30.9x350 - Silver
Ritchey Classic 2-Bolt Post, 30.9x350 - SilverRitchey

3D forged 2014 aluminum shaft, 2-bolt adjustable 2014 aluminum head 38mm rail clamping area. 245g (27.2x350mm) Item Specifications … read more

your price $69.95

BuyBuyPART NUM 616664
RaceFace Ride XC Seatpost 30.9 x 375mm Black
RaceFace Ride XC Seatpost 30.9 x 375mm Black

RaceFace Ride XC Seatposts made of forged AL-6061. 2-bolt head holds saddle securely while retaining easy adjustability Forged, anodized and shot … read more

your price $34.99

BuyBuyPART NUM 283474
Salsa Guide Seatpost 30.9 x 400mm 0mm Offset Black
Salsa Guide Seatpost 30.9 x 400mm 0mm Offset BlackSalsa

The Guide Seatpost features a highly adjustable two-bolt head design, built to be strong, reliable, and supportive when you need it most. Non-Offset … read more

your price $50.00 + ships free

BuyBuyPART NUM 986241
Sunlite Alloy Seatpost, 30.9, 350mm, Black
Sunlite Alloy Seatpost, 30.9, 350mm, BlackSunlite

Forged alloy construction Integrated index adjust seat clamp Weight: 325g Outer Diameter: 30.9mm Length: 350mm Color: … read more

your price $19.99

BuyBuyPART NUM 167908
Thomson Elite Seatpost Silver - 30.9 mm x 367 mm
Thomson Elite Seatpost Silver - 30.9 mm x 367 mmThomson

Over 40% stronger on ultimate strength test than the strongest production seatposts on the market. Over double the fatigue life of any other production … read more

StarStarStarStarStar 4 of 5 ( 2 ) 4 of 5 stars average ( 2 reviews )

your price $114.95 + ships free

BuyBuyPART NUM 102160
Ritchey WCS 1-Bolt Seatpost: 30.9, 400mm, 20mm Offset, Blatte
Ritchey WCS 1-Bolt Seatpost: 30.9, 400mm, 20mm Offset, BlatteRitchey

Wide saddle clamp reduces stress on lightweight saddle rails Works with all saddles with available clamp kits 8x8.5mm or <a hre … read more

your price $99.95 + ships free

BuyBuyPART NUM 691648
Cane Creek

"The world's best choose Cane Creek. A key element of Cane Creek's mission is to support the sport of cycling, including racing, charitable activities and cycling advocacy. Cane Creek believes strongly in the power of bicycles and their potential to effect positive change in our society. To that end, Cane Creek supports athletes and teams whose purpose encompasses more than competitive racing, such as getting more people on bikes, improving or promoting a healthy lifestyle, and making our world better through the use of a bike."

See all Cane Creek

Thomson

Thomson is leading with innovative design for two primary markets - aerospace and cycling.

See all Thomson

Whisky Parts Co.

"Whisky Parts Co. makes high quality carbon components designed with unique features that help you do more with your bike and stand out from the rest. We believe that our work can help every rider find a new level of confidence and performance with our sturdy and lightweight forks, bars, rims and more. So whether you are building a new bike or upgrading one you already have, you'll find an uncommon attention to detail in every product we offer."

See all Whisky Parts Co.

Dimension

Dimension makes quality components to repair or custom-fit the vast majority of bikes being ridden today, and provide the accessories that make them fun to ride.

See all Dimension

Ritchey

"Ritchey bicycle components have been raced to victory in some of the biggest cycling competitions in the world including the UCI World Championships, the Tour de France and the Olympics and it all began in a simple garage in Menlo Park, California with Tom Ritchey.'

See all Ritchey

Salsa

"At Salsa, we believe a sense of adventure makes life better. The bicycle can be so much more than just a bike; it's a path to new places, new people, and amazing experiences."

See all Salsa

Sunlite

"Every year bikes change, styles and trends evolve, old bikes are in need of repairs and new bikes are waiting for that personal touch. We provide the means to keep your bike on the road and fun to ride!"

See all Sunlite

Kind Shock

Kind Shock is an industry leader in suspension and dropper seat posts.

See all Kind Shock

Full Speed Ahead

"We move forward with a desire to deliver the best possible components to our customers and a determined spirit of competition."

See all Full Speed Ahead

RockShox

"An icon in the mountain bike industry."

See all RockShox

We define color as the main color of the item. It may have accents or highlights in other colors.

Weight

These products are one of our best sellers.

In Store products are available to view in our showroom. In Store orders usually ship the same or next business day.

These models are available for online purchasing and can be shipped directly to you.

The seatpost diameter must match to the seat tube diamater of your frame. If replacing a seatpost, you can usually find this measurement etched near the bottom of your current post.

Seatpost length is measured in millimeters. It is typically measured from the bottom of the post to the center of the rail mount.

Offset is often referred to as setback. This is the distance in mm that the clamp is offset from the center of the seatpost.

Seatpost Material

On a dropper post, this is the distance that the post will drop.

Suspension seatposts are designed with comfort in mind.

Seatpost Clamp Style

Clearance items can save you big.

Dropper posts have the ability to change heights. This has become a choice for mountain bike riders that prefer multiple riding positions.

Rigid seatposts are the most common type of seatpost with no suspension or dropping capability.

Our Lowest Price - This product is ineligible for additional discounts or rebates.

Weight

Buy this product and your entire order ships for free.

Some orders are inelligible for delivery discounts. See offer details for disqualifying products and destinations.