How to Choose Mountain Bikes
Co-op Cycles DRT 4.1 Fat-Tire Mountain Bike
$898.93Compared to $1,499.00* Save 40%
When life gives you roots, rocks, sand or snow—anything, really—you'll be thrilled that you can roll over it like it's shag carpet when you're astride the Co-op Cycles DRT 4.1 fat-tire mountain bike.
Key Details
Wheel Size
26 inches
Number of Gears
12 gear(s)
- Strong, rigid aluminum frame keeps the ride fast and saves the weight of a suspension fork—who needs it with those tires soaking up the bumps!
- Fat-tire bikes are all about floating; this one rolls on Innova 26 x 4.8 in. (!) tires that'll glide over just about anything but have low-profile knobs for speed on hardpack
- 1 x 12 drivetrain with SRAM X1 1000 Eagle™ crankset and SRAM SX Eagle 12-speed rear derailleur for swift, streamlined shifting and reduced overall weight
- Shimano hydraulic disc brakes deliver reliable stopping power on or off road and in variable weather conditions
- Front and rear thru axles provide added rigidity
- Bicycle weight limit is 300 lbs. total, including rider plus all gear carried on the bike and on the rider's body
- Pedals not included
- NOTE: Specs and images are subject to change based on component availability
Imported.
This bike comes with Coast to Coast Support, which includes:
New bikes go through a normal break-in period, after which they should be readjusted. All bicycles sold at REI include free adjustments for one year after purchase date—as many times as you need. Included: derailleur and brake adjustments, lateral wheel truing, hub and headset bearing adjustments, tire inflation and chain lubrication. Not included: replacement or installation of new components or accessories, any other services. Call your local REI Co-op Bike Shop for more information.
View the Co-op Cycles DRT Product LineView all Co-op Cycles Rigid Mountain Bikes- 1 year of free adjustments (see more below)
- In-store bike assembly
- Pickup in store or curbside
- Bike experts available at 170+ bike shops
- 20% off shop services
- Free tubes with purchase of flat tire repair (Co-op Cycles brand tubes only; tube must be installed at time of purchase)
New bikes go through a normal break-in period, after which they should be readjusted. All bicycles sold at REI include free adjustments for one year after purchase date—as many times as you need. Included: derailleur and brake adjustments, lateral wheel truing, hub and headset bearing adjustments, tire inflation and chain lubrication. Not included: replacement or installation of new components or accessories, any other services. Call your local REI Co-op Bike Shop for more information.
| Best Use | Mountain Biking |
|---|---|
| Frame | Co-op Cycles 6061 aluminum |
| Mountain Bike Style | Fat-tire |
| Bike Suspension | No Suspension |
| Fork | 6061 aluminum |
| Crankset | SRAM X1 1000 Eagle™ DUB fat 5 |
| Bottom Bracket | SRAM DUB English BSA 100mm fat |
| Shifters | SRAM SX Eagle 12-speed |
| Rear Derailleur | SRAM SX Eagle 12-speed |
| Rear Cogs | SRAM Eagle, 11-50t, 12-speed |
| Number of Gears | 12 gear(s) |
| Brake Type | Hydraulic Disc Brake |
| Brakes | Shimano Acera MT-400 hydraulic disc |
| Brake Levers | Shimano |
| Rims | 26" aluminum |
| Front Hub | 15mm thru axle |
| Rear Hub | 12mm thru axle |
| Wheel Size | 26 inches |
| Tires | Innova 26 x 4.8 in.; 60 TPI |
| Tire Width | 4.8 inches |
| Handlebar Shape | Riser Bar |
| Handlebar | Co-op Cycles alloy butted aluminum riser |
| Stem | Co-op Cycles 6061 aluminum |
| Seat Post | Co-op Cycles 6061 aluminum |
| Saddle | WTB Pure Sport |
| Pedals | Not included |
| Headset | Internal headset |
| Chain | SRAM SX Eagle |
| Weight | 39 pounds |
| Bike Weight | Bike weight is based on median size, as sold, or the average of two median sizes. |
| Gender | Unisex |
| Sustainability | From a Climate Label Certified brand |
Co-op Cycles Bikes (172198)
| XS | S | M | L | XL | |
|---|---|---|---|---|---|
| Reach | 400 | 425 | 450 | 475 | 500 |
| Stack | 573 | 577 | 587 | 596 | 610 |
| Effective Top Tube | 564 | 591 | 618 | 646 | 675 |
| Seat Tube Center-Top | 360 | 395 | 430 | 465 | 500 |
| Standover Height | 704 | 728 | 750 | 773 | 795 |
| Head Tube Angle (degrees) | 68 | 68 | 68 | 68 | 68 |
| Seat Tube Angle (degrees) | 72 | 72 | 72 | 72 | 72 |
| Wheelbase | 1100 | 1127 | 1156 | 1185 | 1215 |
| Chainstay | 445 | 445 | 445 | 445 | 445 |
Sizing Notes
Measurements are stated in millimeters unless otherwise indicated.
How we measure bikes
- Standover Height Standover Height is a measurement from the ground to the top of the top tube, measured at the midpoint of the top tube.
- Reach Reach is the horizontal distance from the center of the cranks to the center of the head tube, measured at head tube level.
- Stack Stack is the vertical distance from the center of the cranks to the center of the head tube, measured to the top of the head tube.
- Effective Top Tube Effective top tube is the distance from the center of the head tube to the center of the seat tube/seat post, measured parallel to the ground.
- Seat Tube Center to Top Seat Tube length is the measurement of the seat tube, from the center of the cranks to the top of the seat tube.
- Head Tube Length Head Tube Length is measured from the bottom to the top of the head tube.
- Head Tube Angle Head Tube Angle is the acute angle between the head tube and the ground (measured towards the rear of the bike)
- Seat Tube Angle Seat Tube Angle is the acute angle between the seat tube and the ground (measured towards the rear of the bike).
- Bottom Bracket Height Bottom Bracket Height is a measurement taken vertically from the ground up to the center of the cranks.
- Wheelbase Wheelbase is the measurement from the center of the front axle to the center of the rear axle.
- Chainstay Length Chainstay Length is the measurement from the center of the cranks to the center of the rear axle.
- Fork Offset Fork Offset, or rake, is the distance from the front axle to a line drawn parallel to the center of the head tube or steering axis.
Buying Advice
Better gear is built together
From feedback to field testing, all of our gear is dialed-in by REI Co-op members. Their adventures informed every stitch and detail—making for better, longer-lasting gear.
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Customer Images
Rock Paperstone
Florida
Through Axles and 4.8 Inch Tire Makes Sand Do-Able
1 year ago
This is my first fat bike and I'm in love with it. I choose the 4.1 based on its componentry and price. I bought this bike on-sale at $1199. I've been a member of the REI Coop since the '90s so I'll be getting a year-end dividend too. At the time I was looking (Memorial Day,) there was no other fat bike, I repeat... no other fat bike available with this level of componentry, service and warranty that could compete with it. I know because I looked, and I looked hard. Luckily, my local REI had a Small 4.1 that I could ride. My inseam is around 29". Normally I buy a size medium in my bikes because I like the extra stretch. Of course, that makes the top bar potentially dangerous, and the 4.1 Small was a little snug but still had some tickle room left. The 4.1 has an excellent set of Shimano hydraulic brakes that stops the 4.1 on a dime and gives change. The Sram 1X12 gear set has performed flawlessly. It has a granny gear I use for the soft stuff and a 12th gear that gets me 15 mph on pavement. My 4.1 weighed in at 37.8 pounds with an add-on aluminum bottle cage. It can be awkward and heavy to load so plan accordingly. I live in Florida so there's plenty of sand here that ordinary mountain bikes can't handle. I took the 4.1 to a beach near St Augustine tried it out. With the granny gear, it handled the soft, dry sand just fine. Wet packed sand was good too. But I just didn't have the legs to power it through unpacked sand on an incline. Still way better performance than my 29'r under like conditions. The 4.1 performed well on pavement too with 17 psig in the tires. The following are things that I might change on the 4.1; Insert metal end caps on the handlebars to protect the grips from ground events, a wider seat for when wearing unpadded shorts and installation of Shrader valves vs the Prestos might make it more pump friendly. Finally, I'm worried about flats and it's been mentioned here before... would tubeless tires and rims make this a better bike? All in all, the 4.1 has expanded my bicycling realm by allowing me to ride where I never could before and for that, I heartily endorse it!
Age:65–74
Weight:125–150 lbs.
Inseam:30"
Height:5'3"
Experience Level:Experienced
Riding Frequency:Multiple times per week
Yes , I recommend this product
JonR
Phoenix, AZ
Great Value
4 years ago
Overall, I think this bike is a great value and a solid example for a fat bike. Co-op has done a great job on the build and components and the bike rides very comfortably and performs well. My main gripe is with the paint. It seems to chip VERY easily. And since REI doesn't seem to offer any touch up paint for the Co-op line, I'm concerned about how this bike will hold up over time. I was holding a small allen wrench about an inch or so above the frame as I was adjusting the handlebars. It slipped out of my hand and hit the top of the frame. Not much of a drop or anything. A nice nick of paint came off exposing the aluminum underneath. I lightly touched the nick and more paint flaked off. I took a quick look around the frame and noticed 3 other nicks from I have no idea what. I've had the bike for 2 weeks, got pedals a week ago, and only ridden a couple times around the neighborhood with my daughter to get a feel for it. I just know it's going to get beat to heck with little rocks and things from the tires when I get it on a trail. This to me is a big deal for a bike that costs $1299 and paint should be the least of my worries unless I am careless or hit something. I'm pretty disappointed. I didn't want to blast the bike in a review over just this as it's really cosmetic and doesn't interfere with the operation of the bike. Still, I think others needs to know what to expect. Pics aren't awesome, but you can see what I mean.
Age:45–54
Weight:150–175 lbs.
Inseam:30"
Height:5'7"
Experience Level:Casual
Riding Frequency:Once per week
Yes , I recommend this product
Anonymous
Carmel, IN
Quality CO-OP Fat Bike
3 years ago
Once I saw this was back in production, I knew that I had to have one. I placed an online order and it showed up to my local REI within a week. Honestly I have zero complaints w this bike. Great components and fair price w an alloy frame! I found that the Blackburn fat tire cargo rack works great on this bike. A few more packs and I'll be ready for some bike packing. As always REI is excellent to work with.
Age:35–44
Weight:200–225 lbs.
Inseam:32"
Height:5'11"
Experience Level:Experienced
Riding Frequency:Multiple times per week
Yes , I recommend this product
Brian W
Beaufort, SC
Love the bike, but…
3 years ago
This was my first Fat-Tire Bike and I really enjoy riding it, the components are quality and appropriate for the bike. The paint looks good in a flat orange, however the paint not having a clear coat is very soft; any straps or hook and loop used to secure frame bags, feed bags, top tube bags etc will rub the paint through to the aluminum frame quickly. I have had to purchase helicopter tape to cover where I know the paint is being rubbed or will be rubbed by straps etc.
Age:45–54
Weight:200–225 lbs.
Inseam:32"
Height:6'0"
Experience Level:Experienced
Riding Frequency:Multiple times per week
Yes , I recommend this product
Adam
Maryland
Worth every penny I paid...
1 month ago
I had been looking at this fat tire bike for whst seems like a few years now. When I noticed it was on sale, it was a no brainer for me! I ordered a size large according to the sizing chart and it worked out perfectly! Couldn't be happier with the quality you get for whst you pay, especially the sale price. Our local (Columbia MD) REI had the bike ready to go just a few days after it was ordered. I did upgrade a few things myself but that was my decision and not done due to faulty parts. I also installed some paint protection on some parts of the frame because of reports from others about having issues with the paint. The bike rolls like you're floating on a cloud and I couldn't be happier with it! Many thanks REI
Age:45–54
Weight:150–175 lbs.
Inseam:32"
Height:5'9"
Experience Level:Experienced
Riding Frequency:Multiple times per week
Yes , I recommend this product
Mark C
Sparks, NV
Lichen this Bike
1 year ago
Great fat bike for the price - very satisfied with the fit and geometry and love floating over the soft sandy stuff for a change. One thing I would have loved to see was tires and wheels that are tubeless compatible. The tires have great tread pattern and love the size, but they weren't thick enough to beat the goatheads - three flat tires as a result of my first ride of 23.5 miles. Easy enough to patch, but not really how I wanted to spend my time.
Age:55–64
Weight:175–200 lbs.
Inseam:32"
Height:5'9"
Experience Level:Experienced
Riding Frequency:Daily
Yes , I recommend this product
George
Florida
Ploughing Through the Sand
3 years ago
My wife and I have been riding fat-tire bikes on the beach for five-plus years. The Co-Op DRT 4.1 has taken the experience to the next level. Love the drive train and hydraulic disc brakes. Thanks to REI team members Blake, Charlotte, Craig, and Jake for pointing us in this direction and making it a reality.
Weight:125–150 lbs.
Inseam:32"
Height:5'8"
Experience Level:Experienced
Riding Frequency:A few times per month
Yes , I recommend this product
Robert
Middleburg, FL
Quality fat bike that goes anywhere
1 year ago
Great fat bike with quality components. Love the nearly 5” wide tires. This thing will go anywhere and is surprisingly light for its size. Buy it- you won’t regret it.
Age:45–54
Weight:125–150 lbs.
Inseam:32"
Height:5'8"
Experience Level:Experienced
Riding Frequency:Multiple times per week
Yes , I recommend this product
Ken S
West Bloomfield Michigan
Great bike for a great price.
4 years ago
This was my first fat tire bike and I'm pretty happy with it so far. I'm 5'10" and 225lbs and a Large frame fit pretty well. It is quite a bit slower and uses quite a bit more leg power to move, but i expected that. Braking seems decent. Shifting was a bit harsh with how hard it shifts, but isn't a deal breaker. For the money, I was very happy with it compared to other brands.
Age:45–54
Weight:200–225 lbs.
Inseam:32"
Height:5'10"
Experience Level:Experienced
Riding Frequency:Multiple times per week
Yes , I recommend this product
Carl
Minneapolis, Mn
Hard to beat for the price
3 years ago
Bought this bike when if first came out to replace an old and outdated fat bike. This bike has nice modern geometry and is in line with the current trends. I also bought this bike knowing I would be upgrading parts like the derailleur, shifter, and tires. Had to replace derailleur fairly soon as a stick got caught in rear mech and removed it for me:) Replaced with sram GX and it has been running like a champ ever since! I use this bike in the winter only for riding snowy single track and my daily commute to work. A quick change of tires to suit conditions makes a huge difference in how it performs. It has about 1,000 miles on it and I have been very pleased! The paint does chip easily as you may have read but I see this bike as a tool and i am not too concerned about it.
Age:25–34
Weight:175–200 lbs.
Inseam:30"
Height:5'10"
Experience Level:Experienced
Riding Frequency:Daily
Yes , I recommend this product
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