MenuMenuModern Bike

31.8 mm 40 mm Bicycle Stems

Bar clamp diameter is the diamater of the handlebar.

Stem length is measured from the center of one clamp to the center of the other clamp. This measurement is sometimes known as the reach or extension.

SortSort

Showing 49 products:

Salsa Guide Trail Stem- 40mm, 31.8 Clamp, 0 Degree, 1 1/8", Aluminum, Black
Salsa Guide Trail Stem- 40mm, 31.8 Clamp, 0 Degree, 1 1/8", Aluminum, BlackSalsa

The Guide Trail Stem translates your handlebar input into precise trail movements. It's an ideal choice for modern trail bikes that have a long front … read more

your price $45.00 + ships free

BuyBuyPART NUM 139349
TruVativ Hussefelt Stem 40mm 0deg 31.8 1-1/8  Black
TruVativ Hussefelt Stem 40mm 0deg 31.8 1-1/8 Black

TruVativ Hussefelt Mountain Stems feature forged 6061-T6 aluminum construction. Forged AL-6061-T6 construction Height = 50mm, 315 grams for 60mm … read more

StarStarStarStarStar 5 of 5 ( 1 ) 5 of 5 stars ( 1 review )

your price $43.00

BuyBuyPART NUM 251355
Whisky No.7 MTN Stem 40mm 31.8 0 Degree Black
Whisky No.7 MTN Stem 40mm 31.8 0 Degree BlackWhisky Parts Co.

No.7 Mountain stems offer a stout connection for modern mountain bars. They match the simple aesthetic of other Whisky cockpit components.  3D-forged … read more

your price $48.00 + ships free

BuyBuyPART NUM 601487
Industry Nine A318 Stem, (31.8) 40mm - Silver
Industry Nine A318 Stem, (31.8) 40mm - SilverIndustry Nine

7075 domestically sourced aluminum is machined, anodized and assembled in North Carolina 180 degree clamp wrap with high strength 316 stainless … read more

your price $145.00 + ships free

BuyBuyPART NUM 171546
Renthal Apex Stem: 31.8, 1-1/8, 40mm Reach, +/- 6 degree
Renthal Apex Stem: 31.8, 1-1/8, 40mm Reach, +/- 6 degree

Renthal Apex Stems. The Renthal Apex combines All Mountain strength, Enduro stiffness and XC lightweight that makes this stem the perfect choice for any … read more

StarStarStarStarStar 5 of 5 ( 1 ) 5 of 5 stars ( 1 review )

your price $140.45 + ships free

BuyBuyPART NUM 324497
Thomson Elite X4 Mountain Stem 40mm +/- 0 degree 31.8 1-1/8" Threadless
Thomson Elite X4 Mountain Stem 40mm +/- 0 degree 31.8 1-1/8" Threadless Thomson

Thomson X4 Mountain Stems feature smooth edges for carbon bar compatibility and use bolts that are custom heat treated with corrosion preventative plating. … read more

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

your price $114.95 + ships free

BuyBuyPART NUM 751094
Thomson Elite X4 Mountain Stem 40mm +/- 0 degree 31.8 1-1/8 Threadless
Thomson Elite X4 Mountain Stem 40mm +/- 0 degree 31.8 1-1/8 Threadless Thomson

Thomson X4 Mountain Stems feature smooth edges for carbon bar compatibility and use bolts that are custom heat treated with corrosion preventative plating. … read more

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

your price $114.95 + ships free

BuyBuyPART NUM 332850
Spank Spoon 2 Stem - 40mm 31.8mm 0 Degree Alloy Black
Spank Spoon 2 Stem - 40mm 31.8mm 0 Degree Alloy Black

Unique style, modern geometry, and rock solid construction, without the heavy price tag. Spank's Spoon Stem is 2D Forged and CNC optimized for strength … read more

your price $45.99 + ships free

BuyBuyPART NUM 664729
Renthal Duo Stem: 40mm 10 Degree 31.8mm 1-1/8" Black / Gold
Renthal Duo Stem: 40mm 10 Degree 31.8mm 1-1/8" Black / Gold

Made in Cheshire, UK CNC machined from 6082 T6 aluminium alloy Split stem design for maximum weight reduction U-shape cradle clamp eliminates handlebar … read more

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

your price $132.95 + ships free

BuyBuyPART NUM 741150
Industry Nine A318 Stem, (31.8) 40mm - Blue
Industry Nine A318 Stem, (31.8) 40mm - BlueIndustry Nine

7075 domestically sourced aluminum is machined, anodized and assembled in North Carolina 180 degree clamp wrap with high strength 316 stainless … read more

your price $145.00 + ships free

BuyBuyPART NUM 792048
Industry Nine A318 Stem, (31.8) 40mm - Gold
Industry Nine A318 Stem, (31.8) 40mm - GoldIndustry Nine

7075 domestically sourced aluminum is machined, anodized and assembled in North Carolina 180 degree clamp wrap with high strength 316 stainless … read more

your price $145.00 + ships free

BuyBuyPART NUM 623590
Industry Nine A318 Stem - 40mm, 31.8mm Clamp, +/-4.4, 1 1/8", Aluminum, Green
Industry Nine A318 Stem - 40mm, 31.8mm Clamp, +/-4.4, 1 1/8", Aluminum, GreenIndustry Nine

Industry Nine's A-Series mountain bike stems are crafted from domestically-sourced 7075 aluminum billet into a svelte design achieving a nexus of form … read more

your price $155.00 + ships free

BuyBuyPART NUM 320357
Industry Nine A318 Stem, 31.8 x 40mm, Pink
Industry Nine A318 Stem, 31.8 x 40mm, PinkIndustry Nine

7075 domestically sourced aluminum is machined, anodized and assembled in North Carolina 180 degree clamp wrap with high strength 316 stainless … read more

your price $145.00 + ships free

BuyBuyPART NUM 641398
Industry Nine A318 Stem, (31.8) 40mm - Black
Industry Nine A318 Stem, (31.8) 40mm - BlackIndustry Nine

7075 domestically sourced aluminum is machined, anodized and assembled in North Carolina 180 degree clamp wrap with high strength 316 stainless … read more

your price $145.00 + ships free

BuyBuyPART NUM 753762
Spank Spoon 2 Stem, 31.8 x 40mm, 0°, Blue
Spank Spoon 2 Stem, 31.8 x 40mm, 0°, Blue

Strong yet competitively lightweight alloy stem for all disciplines Unique style, modern geometry and rock-solid construction Chamfered … read more

your price $45.99 + ships free

BuyBuyPART NUM 392773
Truvativ ATMOS 7K Stem, 31.8 x 40mm, 1-1/8", +/-6d, Black
Truvativ ATMOS 7K Stem, 31.8 x 40mm, 1-1/8", +/-6d, Black

Lightweight, performance stem designed for trail and cross-country use All fasteners are adjustable via a T25 tool for easy,quick adjustments … read more

your price $75.00 + ships free

BuyBuyPART NUM 355310
ProTaper Trail Stem, 31.8 x 40mm, Limited Edition Polished
ProTaper Trail Stem, 31.8 x 40mm, Limited Edition Polished

The ProTaper stem may look simple, but under that beautiful veneer lies hours of 3D modelling, countless FEA revisions, and tons of real-world … read more

your price $104.99 + ships free

BuyBuyPART NUM 456171
Industry Nine A318 Stem, (31.8) 40mm - Red
Industry Nine A318 Stem, (31.8) 40mm - RedIndustry Nine

7075 domestically sourced aluminum is machined, anodized and assembled in North Carolina 180 degree clamp wrap with high strength 316 stainless … read more

your price $145.00 + ships free

BuyBuyPART NUM 611735
Industry Nine A318 Stem, (31.8) 40mm - Purple
Industry Nine A318 Stem, (31.8) 40mm - PurpleIndustry Nine

7075 domestically sourced aluminum is machined, anodized and assembled in North Carolina 180 degree clamp wrap with high strength 316 stainless … read more

your price $155.00 + ships free

BuyBuyPART NUM 207499
Industry Nine A318 Stem, (31.8) 40mm - Orange
Industry Nine A318 Stem, (31.8) 40mm - OrangeIndustry Nine

7075 domestically sourced aluminum is machined, anodized and assembled in North Carolina 180 degree clamp wrap with high strength 316 stainless … read more

your price $145.00 + ships free

BuyBuyPART NUM 515268
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

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.

Industry Nine

"Industry Nine hubs are handmade in Asheville, NC"

See all Industry Nine

Thomson

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

See all Thomson

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

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

These products are one of our best sellers.

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

Bar clamp diameter is the diamater of the handlebar.

Stem length is measured from the center of one clamp to the center of the other clamp. This measurement is sometimes known as the reach or extension.

S.H.I.S clamp diameter is the steerer tube diameter.

Stem angles are measured perpendicular to the clamp. For example, a 90 degree stem is straight. Sometimes, this may also be refered to as a 0 degree stem. If two measurements are listed, the stem can be flipped for angling up or down.

Stem Type

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

This is the part number or identifier for this item from the manufacturer

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.