CRF300RX ENDURO (2021) - Mulders Motoren

CRF300RX ENDURO (2021)

CRF300RX ENDURO (2021)

Introduction

Our decision to expand the CRF platform in 2019, with the introduction of the new CRF250RX is confirmed by the launch of the new CRF300RX Enduro 2021.
Based on the CRF250RX 2021 it is the “big bore” enduro version of RedMoto. Fast, powerful, agile and easy to handle, it is a formidable race bike but above all a splendid Honda enduro for all off-road lovers.
The new CRF300RX 2021 maintains all its strengths already highlighted in the 2020 model that have crowned it “best seller” among the RedMoto enduros in the past season. Lots of low and mid-range torque and lots of power, together with the aluminium frame and swingarm and dedicated suspension set-up to exploit its full potential, make the 300RX the perfect mix for every enduro rider.
As usual the street legal versions both for the Italian and the European market are made by Redmoto S.r.l, official partner of Honda Motor Europe Ltd. for the distribution of the CRF off-road range.

Model Highlight

The CRF300RX Enduro takes advantage of the solid base of its brother 250 from which it differs in the adoption of a cylinder with an increased diameter. It has a 7.3 litre tank, an 18” rear wheel and a dedicated suspension set up. The bike has a forged aluminium side stand.

For the 2021 model the ECU mappings have been revised for an even more homogeneous power delivery.
Already for the 2020, the development of the twincam 300cc engine was aimed at the improvement of torque at low and mid-range rpm. Honda’s engineers hit the mark. Thanks to a radically new design of the combustion chamber, the new twin-cam engine can claim both a higher midrange torque and more power at high revs.
Second gear ratio is now closer to third gear to reduce the natural rev drop during gear change. Clutch performance has been improved as well. Furthermore, optimized intake and exhaust flows and updated engine maps make riding even more effective.

Frame and swingarm on the CRF300RX are the same of the CRF 250RX, lighter but most of all they have an optimized rigidity. The new chassis takes full advantage of the new dedicated suspension set up, and improves stability, the feeling of control, and driving precision through high speed turns on rough terrains.

Main Features

Engine

• 3 EMSB dedicated Maps
• Ignition timing and gear by gear Honda PGM-FI maps
• Narrower second gear ratio to reduce rpm drop on gear change

 

The CRF300RX Enduro shares the engine with its 250 2021 brother, but features revised ignition and fueling mappings for a gradual and more manageable power delivery on the diversified funds typical of the enduro.
Max power is at 11,300rpm and maximum torque is at 9,500rpm. The rev limiter is at 14,300rpm, in order to let the rider use the same gear beyond max power, a very useful feature for the enduro racer.
The improvements have been achieved already from the 2020 model, through revised shaping of the inlet/exhaust ports, piston and combustion chamber, and a new cam profile which keep the exhaust valves open for longer with more overlap with the opening of the intake valves. The internal volume of the exhaust ports goes from 12cm3 to 12.7cm3, while the piston crown’s cutaways are re-shaped, increasing volume from 21.7cm3 to 22.2cm3. And to cope with the extra heat generated by the harder-working engine the radiator volume has been increased.

To maintain engine rpm when shifting from 2nd to 3rd the gap between the two gears is closer; 2nd is now 16 main/28 counter giving a 1.75 ratio (from 15/27, 1.8) while 3rd remains 17/25 and 1.47.
To improve durability 3rd and 4th gear gain a new surface treatment; and, like the CRF450RX, the addition of a gear position sensor allows the use of three specific ignition maps for 1st and 2nd, 3rd and 4th, and 5th. The clutch spring rate has also been increased, giving an 18% increase in performance.

Bore and stroke remains 86 x 50.9mm, with a 4.5mm cylinder offset to reduce friction. The valves are titanium; 33mm inlet and 26mm exhaust. Lift is 10.5mm inlet and 9.5mm exhaust and the valve angle is set at 20.5°. The valve springs themselves are oval in section; the inlet valves are fed by symmetrical straight-shot downdraft intakes.
The cylinder born in collaboration with ATHENA already in 2020 presents a chromium-plated steel barrel with nickel-chromium drowned in the casting. The design increases the capacity of the coolant; a 5-hole piston oil jet maintains optimum piston cooling and ignition timing. A scavenge oil pump system reduces friction and ‘pumping’ losses at high rpm, by discharging oil and air in the crankcase and maintaining negative pressure. The oil also lubricates the clutch and gearbox, with a total oil capacity of 1.25L.

The combined oil pump/drive gear, oil filter and oil way are on the right side of the engine – the oil’s path around the engine is short and straightforward. Valve train lubrication is routed through the cylinder head to the inside of both inlet and exhaust cam, directly feeding the sliding surface of cam and rocker arm. The 5-speed gearbox drives a sealed 520 chain.

Electronics

• HRC 3 modes launch control
• 3 power modes EMSB (Engine Mode Select Button)
HRC Launch Control, introduced on the 2019 model, offers the best stand still starting option in any situation. It has three modes:
Mode 3: 8,250 rpm, mud / beginner;
Mode 2: 8.500 rpm, dry surface / amateur;
Mode 1: 9.500 rpm, dry surface / expert rider.

Launch control activation is easy: just pull the clutch lever and press ignition switch. LED light flashes once to indicate mode 1. Press the ignition switch once more for 5 seconds, LED light blinks twice to indicate mode 2 has been selected. Repeat the procedure and LED light flashes three time to indicate mode 3 has been selected.
The Engine Mode Select Button lets the pilot choose the engine character that best suits the track conditions. From a standing position, with the engine idling, pressing the button for less than 1 second will select the map in ascending order. Rapidly pressing the button, the integrated LED indicates the selected map flashing the corresponding number of times (1 flash, mode 1 etc). Every time a different map is selected, the integrated LED flashes the corresponding number of times.

Mode 1 (Standard) uses a default combination of ignition and fuel injection settings.
Mode 2 (Smooth) offers a soft and smooth, easy to handle power delivery, perfect for slippery surfaces.
Mode 3 (Aggressive) offers the perfect combination of power and torque for maximum responsiveness.

The switchgear with commands like engine stop, EFI indicator, EMSB button and LED indicator are on the left handlebar.

Chassis

• Aluminium frame and swingarm 7th generation same of CRF 250RX
• Stability and riding precision through turns
• Enduro Showa suspension setup for better effectiveness braking and accelerating

The 2021 CRF300RX Enduro has the same seventh generation frame of the CRF 250RX, a well-aimed evolution of the 2019 CRF 450RX model. Thanks to a thinner swingarm pivot area and it is designed to have greater torsional and lateral stiffness to increase agility and riding through turns, but also to have higher angular yaw rigidity to improve stability and grip while turning.
The aluminium swingarm is balanced to work as one with the frame. The 4 tie footrests help to better remove mud and are also lighter. The battery is positioned lower to better centralize masses.
The caster angle is 27°18’ and trail is 116mm. Wheelbase is 1,486mm. Curb weight is 111kg. The 49mm upside down Showa fork is just like the ‘factory’ one used for racing, with a 14mm rod, a 39mm piston and a 25mm diameter cylinder.

Starting from the 2020 model, in order to improve response during hard braking, the diameter of the main ‘B’ oil duct on the rod is decreased to 1.6mm from 2.4mm, to decrease low speed dumping. The same way the main hydraulics of the shock absorber are modified to increase control under acceleration.
The Renthal Fatbar handlebar reduces the overall weight of the steering system and is flexible enough to reduce riding stress. Bar risers can be mounted in two different positions 26mm apart (back and forth) on the top yoke. Turning the risers by 180° the handlebar moves 10 more millimetres. This way there are 4 different positions available. The central bumper is standard equipment.
The front brake calliper, biting on a 260mm wave disk, has two pistons of different diameter, 30mm and 27mm to be lighter and to have a reduced fading under heavy breaking. It guarantees power and feel. At the back a single piston calliper bite on a 240mm disk. The 2021 CRF300RX Enduro uses rear brake pads that increase power and duration thus allowing to remove the read disc cover.
The light full black DID DIRT STAR aluminium wheels have direct-mount spokes to reduce unsprang masses. The front wheel size is 21×1,6” and the back-wheel size is 18×2,15. The Metzeler Six Days Extreme tyres size is respectively 90/90-21 and 140/80-18.

The 7,3 litres white fuel tank allows to check fuel level at a glance. The streamlined lines of the CRF design help the rider to move freely while the tight front area and the front conveyors help funnelling air to the radiator.

The CRF300RX Enduro has a sturdy finish with resistant HRC style stickers.

The front fender for the full led headlight perfectly integrates with the streamlined CRF design.

Sturdy back mudguard with integrated support for the registration plate, that also increases the resistance to the hits, typical of heavy off-road use.

The new side stand elastic band support perfectly integrates with the bike’s ergonomics.


 

 

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Specificaties CRF300XR (2021)
 

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