RockyMounts Tomahawk Roof Bike Rack or RockyMounts BrassKnuckles Upright Roof Bike? Which RockyMounts Model to Buy
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Choosing between the rockymounts tomahawk roof bike rack vs brassknuckles upright roof bike depends on your specific tire needs. Both models mount to roof crossbars and secure bikes without touching the frame. They share a similar weight profile and hold single bicycles. The main difference lies in tire compatibility. The Tomahawk supports wider tires out of the box, while the BrassKnuckles offers a more compact footprint for standard road and mountain bikes.
Key differences
| Aspect | RockyMounts Tomahawk Roof Bike Rack | RockyMounts BrassKnuckles Upright Roof Bike Rack |
|---|---|---|
| Tire Width Capacity | Up to 5 inches out of the box | Up to 3.0 inches (5 inches with optional fattie kit) |
| Dimensions | 38 inches wide, 13 inches high | 37 inches long, 5.98 inches high |
| Weight | 18 pounds | 18 pounds |
| Mounting Straps | Not listed | Form-fitting stainless steel straps |
Which one should you choose?
Choose RockyMounts Tomahawk Roof Bike Rack if
- You ride fat bikes with tires up to 5 inches wide and want immediate compatibility without extra parts.
- You prefer a rack that adjusts easily for driver or passenger side installation.
Choose RockyMounts BrassKnuckles Upright Roof Bike Rack if
- You prioritize a lower profile design with a height of under 6 inches for reduced wind resistance.
- You want ergonomic brass knuckle-shaped handles for easier loading and unloading.
Verdict: Select the Tomahawk if you frequently ride fat bikes or need maximum tire clearance without accessories. Choose the BrassKnuckles for a slimmer profile and ergonomic handling with standard road or mountain bike tires. Both racks provide secure, frame-free transport for your bicycle.
Tomahawk vs BrassKnuckles Key Specs
Overall Dimensions
The RockyMounts Tomahawk measures 38 inches in length, making it slightly longer than the BrassKnuckles at 37 inches. Height differs significantly, with the Tomahawk standing 13 inches tall compared to the BrassKnuckles at just under 6 inches. Width is also distinct, as the Tomahawk is 3.46 inches wide while the BrassKnuckles spans 24 inches across. These physical footprints affect how each unit sits on your roof rack. You should check your crossbar spacing to ensure either model fits comfortably without overhang. The Tomahawk is taller, which may impact aerodynamics differently than the lower-profile BrassKnuckles design.
Tire Compatibility
Both racks handle a wide range of wheel sizes from 20 to 29 inches. The Tomahawk supports fat bike tires up to 5 inches wide right out of the box, including extensions. The BrassKnuckles handles road tires up to 3.0 inches and mountain bike tires naturally, but requires an additional fattie kit to reach that 5-inch width limit. If you frequently ride fat bikes, the Tomahawk offers immediate readiness. For standard road or trail bikes, both work well. You need to decide if carrying that extra fattie kit for the BrassKnuckles is worth the storage space.
Weight Profile
Both the Tomahawk and the BrassKnuckles weigh exactly 18 pounds. This identical weight means neither unit adds significant extra load to your vehicle’s roof. You will not notice a difference in fuel efficiency or handling based on the rack’s mass alone. The balance of weight distribution might vary slightly due to the different shapes, but the total mass is equal. This makes them comparable in terms of raw weight impact on your car. You can choose based on other features without worrying about one being noticeably heavier than the other.
Crossbar Compatibility
Each model mounts to round, square, factory, and aero crossbars. The BrassKnuckles specifies a minimum crossbar spread of 24 inches and a maximum of 43 inches. The Tomahawk data does not list specific spread limits, only that it mounts to all styles. You should verify your crossbar width falls within the BrassKnuckles range to ensure a secure fit. The Tomahawk’s swingarm adjusts for driver or passenger side installation, offering flexibility in placement. Both use form-fitting straps to secure the base. Check your bar spacing carefully before purchasing either option.
Load Capacity
The BrassKnuckles specifies a maximum bike weight of 45 pounds on RockyMounts, Thule, or Yakima bars, and 35 pounds on factory crossbars. The Tomahawk data does not list a specific weight limit for the bicycle. You must assume the Tomahawk has a limit, but it is not provided in the specs. If you carry a very heavy e-bike, the BrassKnuckles gives you clear numbers to follow. For lighter bikes, both likely handle the load. Always prioritize the lower limit if using factory bars with the BrassKnuckles.
Which RockyMounts Rack Fits You
You have fat bikes with wide tires
The Tomahawk accommodates tires up to 5 inches wide right out of the box. It includes two wheel strap extensions to handle this extra width. The BrassKnuckles requires a separate fattie kit for tires wider than 3 inches. If you ride fat bikes, the Tomahawk saves you the cost and hassle of buying additional accessories.
You want a lower profile for wind
The BrassKnuckles stands only 5.98 inches tall. The Tomahawk is significantly taller at 13 inches. A lower height reduces wind resistance and noise while driving. The BrassKnuckles also has a narrower width of 24 inches compared to the Tomahawk. This compact shape may help you fit more gear on your roof alongside the rack.
You need adjustable swingarm positioning
The Tomahawk features a swingarm that adjusts for driver or passenger side installation. This allows you to place the bike closer to the center of the vehicle. The BrassKnuckles data does not mention this adjustable positioning feature. If you want to optimize balance or access your rear hatch easily, the Tomahawk offers this specific mechanical advantage.
The products compared
RockyMounts Tomahawk Roof Bike Rack
Best for: fat bikes and frame-safe transport
- Mount Type
- roof
- Tire Width
- up to 5"
- Frame Contact
- no bike frame contact
- Size
- One Size
- Dimensions
- 3.46 × 38 × 13 inches
- Weight
- 18 pounds
View on Amazon: RockyMounts Tomahawk Roof Bike Rack Affiliate link
The RockyMounts Tomahawk is an upright roof bike rack that holds bikes by the front wheel only. It features a 38-inch width and weighs 18 pounds. The design avoids frame contact, making it safe for various frames. It fits crossbars of all shapes and supports tires up to 5 inches wide. This rack suits drivers who need a secure, upright solution for standard or fat bikes without touching the frame.
Pros
- No bike frame contact for frame safety
- Supports fat bikes up to 5-inch tires
- Swingarm adjusts for driver or passenger side
- Mounts to round, square, factory, or aero bars
Cons
- 18-pound weight is substantial for loading
- 38-inch width requires adequate roof space
- Does not fit bikes with front fenders
Good fit if
- You need to transport fat bikes with wide tires
- You want to avoid contact with your bike frame
- You have roof crossbars of any common shape
Skip if
- You use bikes with front fenders attached
- You prefer a low-profile rack under 15 pounds
- You have very narrow roof crossbars
Verdict: The RockyMounts Tomahawk Upright Roof Bike Rack is a sturdy, frame-safe option for riders with fat bikes or varied crossbar shapes. It fits best for drivers who prioritize frame protection and wide tire compatibility over lightweight portability.
RockyMounts BrassKnuckles Upright Roof Bike Rack
Best for: single bike owners avoiding wheel removal
- Bike Capacity
- 1
- Mount Type
- roof
- Size
- One Size
- Use
- Bike
- Dimensions
- 37 × 24 × 5.98 inches
- Weight
- 18 pounds
View on Amazon: RockyMounts BrassKnuckles Upright Roof Bike Rack Affiliate link
This rack carries one bike upright without removing the front wheel. It secures the bicycle by the front wheel, avoiding frame contact. It fits road tires up to 3.0 inches wide and mountain bike tires up to 5 inches with an optional kit. The rack supports wheelbases from 34 to 48 inches and handles bikes up to 45 pounds on dedicated bars or 35 pounds on factory crossbars.
Pros
- No front wheel removal required
- Fits tires up to 3.0 inches wide, or 5 inches with fattie kit
- Compatible with wheelbases from 34 to 48 inches
- Secures bike by front wheel to avoid frame contact
- Fits crossbars from 24 to 43 inches wide
Cons
- Carries only one bike
- Heavier at 18 pounds
- Requires fattie kit for tires wider than 3.0 inches
Good fit if
- You want to avoid removing the front wheel
- You have wide tires up to 3.0 inches
- You need to protect your bike frame from contact
Skip if
- You need to carry more than one bike
- You have tires wider than 5 inches
- You want a lighter rack under 10 pounds
Verdict: RockyMounts BrassKnuckles Upright Bike Rack is a solid option for riders who prefer not to remove their front wheel. It suits those with standard to moderately wide tires who value frame protection over carrying multiple bikes.
Specifications side by side
| Spec | RockyMounts Tomahawk Roof Bike Rack | RockyMounts BrassKnuckles Upright Roof Bike Rack |
|---|---|---|
| Bike Capacity | not stated | 1 |
| Mount Type | roof | roof |
| Tire Width | up to 5" | not stated |
| Frame Contact | no bike frame contact | not stated |
| Size | One Size | One Size |
| Use | Bike | Bike |
| Dimensions | 3.46 × 38 × 13 inches | 37 × 24 × 5.98 inches |
| Weight | 18 pounds | 18 pounds |
| Color | Black | Black |
| Model | 1222 | 12010 |
Frequently asked questions
Do the Tomahawk and BrassKnuckles use the same mounting hardware?
Both racks mount to standard roof crossbars. They share the same 18-pound weight, indicating similar structural robustness. The Tomahawk is model 1222, while the BrassKnuckles is model 12010. You should verify that your vehicle’s crossbars match the clamp requirements for upright roof bike racks before purchasing either option.
Which rack is better for wide fat bike tires?
The Tomahawk is designed for fat bikes and wide tires. It accommodates tires up to 5 inches wide using included wheel strap extensions. The BrassKnuckles is better for standard to moderately wide tires. It requires a separate fattie kit to handle wider profiles, making the Tomahawk the more ready-to-use choice.
How much roof space does each rack occupy?
The Tomahawk is 38 inches long and 3.46 inches wide. The BrassKnuckles is 37 inches long and 3 inches wide. Both are One Size. The Tomahawk is slightly longer and wider. This minimal difference means either rack will fit on most standard roof crossbar setups without significant spatial issues.
Will these racks damage my bike frame?
No, neither rack touches your bike frame. Both are frame-safe options that secure the bike by the wheels. The Tomahawk is noted for frame protection. The BrassKnuckles also avoids frame contact. This design protects your paint and frame integrity during transport, regardless of which model you choose.
Is one rack significantly lighter than the other?
No, they weigh the same. Both the Tomahawk and the BrassKnuckles weigh 18 pounds. This identical weight profile suggests similar material density and construction quality. You will not gain any portability advantage by choosing one over the other based on weight alone. Both are substantial upright racks.
Can I use the BrassKnuckles for a fat bike without extra parts?
You cannot use it out of the box for very wide tires. The BrassKnuckles suits standard to moderately wide tires. For fat bikes, you need a separate fattie kit. The Tomahawk includes the necessary extensions for wide tires. If you own a fat bike, the Tomahawk is the direct fit.
What are the height differences between the two models?
The Tomahawk is 13 inches tall. The BrassKnuckles is 5.98 inches tall. This is a significant difference in vertical profile. The lower height of the BrassKnuckles may result in a slightly lower center of gravity. The Tomahawk’s taller design accommodates its wider tire capacity structure.
Are these racks suitable for carrying multiple bikes?
No, both are designed for single bike owners. Each rack holds one bicycle. The Tomahawk prioritizes frame protection for that single bike. The BrassKnuckles also suits single bike owners who avoid wheel removal. You would need additional racks if you plan to transport more than one bicycle at a time.