Run your favorite 31.8mm clamping diameter handlebar on a bike with Knock Block with the Rhythm Comp 31.8. It adds Knock Block compatibility to a durable stem with multiple lengths to let you fine-tune the fit to your ride.
Product details
Get 31.8mm handlebar compatibility with your Knock Block system
Also compatible with standard headsets and spacers
Knock Block system protects frame from impacts by fork and handlebars by eliminating over-rotation of bars
Available in a wide range of sizes for today's mountain rider
See Service Parts for other Knock Block parts
if (typeof dataLayer !== "undefined") {
dataLayer.push({
"ecommerce": {
"currency": "USD",
"impressions": [
{
"id": "32193",
"name": "Bontrager XXX Integrated Road Handlebar/Stem",
"price": "599.99",
"brand": "Bontrager",
"category": "Bike handlebars & accessories",
"variant": "black",
"list": "More Options",
"position": 1
}
,
{
"id": "22259",
"name": "Bontrager XXX Blendr Stem",
"price": "275.0",
"brand": "Bontrager",
"category": "Bike stems & seatposts",
"variant": "black",
"list": "More Options",
"position": 2
}
,
{
"id": "23234",
"name": "Bontrager Pro Blendr Stem",
"price": "114.99",
"brand": "Bontrager",
"category": "Blendr integration",
"variant": "black",
"list": "More Options",
"position": 3
}
,
{
"id": "31465",
"name": "Bontrager Elite Stem",
"price": "64.99",
"brand": "Bontrager",
"category": "Bike stems & seatposts",
"variant": "black",
"list": "More Options",
"position": 4
}
,
{
"id": "24160",
"name": "Bontrager Comp 31.8 7 Degree Stem",
"price": "29.99",
"brand": "Bontrager",
"category": "Bike stems & seatposts",
"variant": "black",
"list": "More Options",
"position": 5
}
,
{
"id": "14762",
"name": "Bontrager Kovee Pro 35 13 Degree Blendr Stem",
"price": "114.99",
"brand": "Bontrager",
"category": "Blendr integration",
"variant": "black",
"list": "More Options",
"position": 6
}
,
{
"id": "33106",
"name": "Bontrager Line Pro 35 0 Degree Blendr Stem",
"price": "99.99",
"brand": "Bontrager",
"category": "Bike stems & seatposts",
"variant": "black",
"list": "More Options",
"position": 7
}
,
{
"id": "24156",
"name": "Bontrager Line 35 0 Degree Stem",
"price": "39.99",
"brand": "Bontrager",
"category": "Bike stems & seatposts",
"variant": "black",
"list": "More Options",
"position": 8
}
,
{
"id": "23239",
"name": "Bontrager XXX Integrated Road Handlebar/Stem Legacy",
"price": "449.99",
"brand": "Bontrager",
"category": "Bike handlebars & accessories",
"variant": "black",
"list": "More Options",
"position": 9
}
,
{
"id": "24155",
"name": "Bontrager Line Pro 35 0 Degree Stem",
"price": "99.99",
"brand": "Bontrager",
"category": "Bike stems & seatposts",
"variant": "black",
"list": "More Options",
"position": 10
}
,
{
"id": "31115",
"name": "Bontrager Line Pro Factory Overstock Stem",
"price": "60.0",
"brand": "Bontrager",
"category": "Factory overstock",
"variant": "black",
"list": "More Options",
"position": 11
}
,
{
"id": "31114",
"name": "Bontrager Rhythm Pro Direct Mount Factory Overstock Stem",
"price": "50.0",
"brand": "Bontrager",
"category": "Factory overstock",
"variant": "black",
"list": "More Options",
"position": 12
}
,
{
"id": "24636",
"name": "Bontrager Rhythm Pro Factory Overstock Stem",
"price": "40.0",
"brand": "Bontrager",
"category": "Factory overstock",
"variant": "black",
"list": "More Options",
"position": 13
}
,
{
"id": "24637",
"name": "Bontrager RXL 7 Degree Factory Overstock Stem",
"price": "40.0",
"brand": "Bontrager",
"category": "Bike stems & seatposts",
"variant": "white",
"list": "More Options",
"position": 14
}
,
{
"id": "14351",
"name": "Bontrager Blendr Adjustable Quill Stem",
"price": "29.99",
"brand": "Bontrager",
"category": "Bike stems & seatposts",
"variant": "black",
"list": "More Options",
"position": 15
}
]
}
});
}
if (typeof dataLayer !== "undefined") {
dataLayer.push({
"ecommerce": {
"currency": "",
"impressions": [
{
"id": "21821",
"name": "Bontrager Ballista MIPS Road Bike Helmet",
"price": "",
"brand": "Bontrager",
"category": "Bike helmets",
"list": "",
"position": 1
}
,
{
"id": "21834",
"name": "Bontrager Starvos MIPS Cycling Helmet",
"price": "",
"brand": "Bontrager",
"category": "Bike helmets",
"list": "",
"position": 2
}
,
{
"id": "21797",
"name": "Bontrager Rally MIPS Mountain Bike Helmet",
"price": "",
"brand": "Bontrager",
"category": "Bike helmets",
"list": "",
"position": 3
}
,
{
"id": "21764",
"name": "Bontrager Circuit MIPS Cycling Helmet",
"price": "",
"brand": "Bontrager",
"category": "Bike helmets",
"list": "",
"position": 4
}
,
{
"id": "23999",
"name": "Bontrager Flare RT Rear Bike Light",
"price": "",
"brand": "Bontrager",
"category": "Bike lights",
"list": "",
"position": 5
}
,
{
"id": "23709",
"name": "Bontrager Ion 200 RT Front Bike Light",
"price": "",
"brand": "Bontrager",
"category": "Bike lights",
"list": "",
"position": 6
}
,
{
"id": "22466",
"name": "Bontrager Ion Pro RT Front Bike Light",
"price": "",
"brand": "Bontrager",
"category": "Bike lights",
"list": "",
"position": 7
}
,
{
"id": "14259",
"name": "Bontrager Ion 100 R/Flare R City Bike Light Set",
"price": "",
"brand": "Bontrager",
"category": "Bike lights",
"list": "",
"position": 8
}
,
{
"id": "13585",
"name": "Bontrager XR4 Team Issue TLR MTB Tire",
"price": "",
"brand": "Bontrager",
"category": "Bike tires",
"list": "",
"position": 9
}
,
{
"id": "14010",
"name": "Bontrager Montrose Comp Bike Saddle",
"price": "",
"brand": "Bontrager",
"category": "Bike saddles",
"list": "",
"position": 10
}
,
{
"id": "21588",
"name": "Bontrager Commuter Comp Bike Saddle",
"price": "",
"brand": "Bontrager",
"category": "Bike saddles",
"list": "",
"position": 11
}
,
{
"id": "21831",
"name": "Bontrager Garmin Edge 1030 GPS NA Cycling Computer",
"price": "",
"brand": "Bontrager",
"category": "Bike computers & GPS",
"list": "",
"position": 12
}
,
{
"id": "21829",
"name": "Bontrager RIDEtime Cycling Computer",
"price": "",
"brand": "Bontrager",
"category": "Bike computers & GPS",
"list": "",
"position": 13
}
,
{
"id": "23110",
"name": "Bontrager Gel Cork Handlebar Tape Set",
"price": "",
"brand": "Bontrager",
"category": "Bike handlebar grips & tape",
"list": "",
"position": 14
}
,
{
"id": "23595",
"name": "Bontrager XR Trail Comp MTB Grip Set",
"price": "",
"brand": "Bontrager",
"category": "Bike handlebar grips & tape",
"list": "",
"position": 15
}
,
{
"id": "25484",
"name": "Bontrager Elite Water Bottle Cage",
"price": "",
"brand": "Bontrager",
"category": "Bike water bottles & cages",
"list": "",
"position": 16
}
,
{
"id": "22370",
"name": "Bontrager Comp MTB Pedal Set",
"price": "",
"brand": "Bontrager",
"category": "Bike pedals",
"list": "",
"position": 17
}
,
{
"id": "22373",
"name": "Bontrager Comp Multi-Tool",
"price": "",
"brand": "Bontrager",
"category": "Bike tools & maintenance",
"list": "",
"position": 18
}
,
{
"id": "25255",
"name": "Bontrager Standard Schrader Valve Bicycle Tube",
"price": "",
"brand": "Bontrager",
"category": "Bike tubes & tubeless bike tire accessories",
"list": "",
"position": 19
}
,
{
"id": "25254",
"name": "Bontrager Standard Presta Valve Bicycle Tube",
"price": "",
"brand": "Bontrager",
"category": "Bike tubes & tubeless bike tire accessories",
"list": "",
"position": 20
}
,
{
"id": "26592",
"name": "Trek T-Shirt",
"price": "",
"brand": "Trek",
"category": "T-Shirts",
"list": "",
"position": 21
}
,
{
"id": "22824",
"name": "Bontrager Evoke Mountain Glove",
"price": "",
"brand": "Bontrager",
"category": "Full finger cycling gloves",
"list": "",
"position": 22
}
,
{
"id": "13675",
"name": "Bontrager Ballista Road Shoe",
"price": "",
"brand": "Bontrager",
"category": "Road bike shoes",
"list": "",
"position": 23
}
,
{
"id": "25335",
"name": "Bontrager Cambion Mountain Bike Shoe",
"price": "",
"brand": "Bontrager",
"category": "Mountain bike shoes",
"list": "",
"position": 24
}
,
{
"id": "21726",
"name": "Bontrager Espresso Road Shoe",
"price": "",
"brand": "Bontrager",
"category": "Road bike shoes",
"list": "",
"position": 25
}
,
{
"id": "21727",
"name": "Bontrager Cortado Women's Road Shoe",
"price": "",
"brand": "Bontrager",
"category": "Road bike shoes",
"list": "",
"position": 26
}
,
{
"id": "11723",
"name": "Bontrager Race 5" Wool Cycling Sock",
"price": "",
"brand": "Bontrager",
"category": "Cycling socks",
"list": "",
"position": 27
}
,
{
"id": "14798",
"name": "Bontrager Rapid Pack",
"price": "",
"brand": "Bontrager",
"category": "Bike bags, baskets & panniers",
"list": "",
"position": 28
}
]
}
});
}
We reserve the right to make changes to the product information contained on this site at any time without notice, including with respect to equipment, specifications, models, colors, and materials.
Weights are based off Trek pre-production products at time of publication. Weights may vary in final production.
