The 2021 Honda CRF450R is the most anticipated motocross bike of the new model year release. Honda has revamped the CRF450R into a lighter, more refined machine! Here are some photos/illustrations as well as the changes/differences that were made from the previous year Honda CRF450R to the new 2021 model. If you want to listen to more CRF talk and why Honda made these changes in 21, click the PODCAST tab on Keeferinctesting.com to listen to the RMATVMC Keefer Tested Podcast.
Engine | Exhaust PortChange Points
๏ More centrally located๏ Oval shaped vs. round
Benefit
๏ Improved exhaust efficiency๏ Increased power: mid-to-high (5000 rpm, up)
Engine | ExhaustChange Points
๏ Single muffler๏ More direct path to rear
Benefit
๏ 2.7 lbs. weight savings๏ Narrower (rear & header area)๏ Improved exhaust efficiency๏ Improved rideability in low-rpm.
Design Decompression System Camshaft
Change Points
๏ Revised layout๏ Revised valve timing๏ Revised valve lift
Benefit
๏ Increased combustion stability: Low rpm๏ Engine power increase
Engine | ClutchChange Points
๏ 27% larger capacity๏ Additional clutch plate๏ Additional friction spring๏ Hydraulically actuated
Benefit
๏ Reduced slip / more consistant performance๏ Lighter lever pull
Engine | Air FilterChange Points:
๏ Air box: 4.1l vs. 1.8l (increase on clean side)๏ New air filter design & mount style๏ New air filter access point (left side)
Benefit:
๏ Improved torque feel at low speed range๏ Air filter easier to service๏ Air filter access: Only 1 bolt to remove
Engine | Fuel InjectorChange Points:
๏ Injector angle increased: 60° vs. 30°
Benefit:
๏ Improved cooling of air through intake path๏ Improved intake efficiency
Engine | Fuel PumpChange Points:
๏ Size reduction w/ same performance
Benefit:
๏ 120g weight reduction๏ Removed via 4 bolts vs. 6
Engine | RadiatorChange Points:
๏ Optimized angle of radiator fins๏ Optimized # of radiator fins
Benefit:
๏ 5% improvement in cooling performance
CHASSIS:
Chassis | FrameChange Points:
๏ Steering head๏ Redesigned downtube๏ Narrower main spars
Benefit:
๏ Reduced lateral rigidity: 20%๏ 1.54 lbs. weight reduction๏ Sharp cornering๏ Great stability
Chassis | SwingarmChange Points:
๏ Narrower design๏ Optimized rigidity
Benefit:
๏ Increased clearance in ruts๏ Improved traction and cornering
Chassis | Pivot PlateChange Points:
๏ Rearranged reinforcement ribbingBenefit:
๏ Reduced lateral rigidity*Frame’s torsional rigidity is unchanced
Chassis | SubframeChange Points:
๏ Simplified design๏ Eliminated seat support structure
Benefit:
๏ 2 lbs. overall weight — .7 lbs. reduction
SUSPENSION:
Suspension | Showa ForkChange Points:
๏ 5 mm more stroke๏ Revalved๏ Axle clamps: increased rigidity
Benefit:
๏ Improved bump absorption๏ Smoother fork movement
Suspension | Showa Shock
Change Points:
๏ Revised settings๏ Larger main piston valving๏ Super-lightweight steel spring๏ Revised Pro-Link ratio
Benefit:
๏ Improved responsiveness๏ .4 lbs. weight reduction
Suspension | Triple ClampChange Points:
๏ Top and bottom clamps with more flex
Benefit:
๏ Quick steering characteristics๏ Improved feel on corner entry
Geometry:
Wheelbase: 1 mm shorter
Rake: .5° steeper
Trail: Reduced 2 mm
Swingarm angle: Increased .9°
Ground clearance: Increased 8 mm
Design:
Design | SeatChange Points:
๏ Seat mounts redesigned๏ Design: Shorter & 10 mm higher at rear
Benefit:
๏ Improved freedom of movement๏ .4 lbs. weight reduction๏ Easier to remove/install seat
Design | Handlebar LayoutChange Points:
๏ Redesigned cable layout
Benefit:
๏ Reduced cable / weight at handlebar area
Design Bodywork Radiator Shrouds
Change Points:
๏ Redesigned, one-piece radiator shroud๏ Left-side panel: 50 mm inboard๏ Right-side panel: 20 mm inboard๏ All bodywork bolts: 8 mm head
๏ Hardware reduction: 8 bolts vs. 12
Benefit:
๏ Improved ventilation to radiators๏ Reduced maintenance time
Design | Fuel TankChange Points:
๏ Reshaped
*Dimensions & updates contribute to bike’s 3 lbs. overall weight reduction
