– Detailed 2018 CRF250R Review of Specs + R&D Engineering, Development | CRF 250R Dirt Bike / Motorcycle Buyer’s Guide –
The “Absolute Holeshot” philosophy that helped revolutionize the latest-generation 2018 CRF450R now makes its way to the all-new CRF250R, a model that has earned no fewer than nine AMA Supercross championships and two AMA Motocross championships over the years. Updates are aimed at achieving maximum power (particularly at high revs) and superb handling, the vastly updated four-stroke engine now featuring a dual-overhead-cam design, twin exhaust ports, and more over-square dimensions. Mass is lower and more centralized, through vehicle- packaging updates like a titanium fuel tank and extruded-aluminum subframe brackets, while a lighter aluminum frame with optimized flex characteristics helps handling and rider feedback. An electric starter, powered by a lightweight lithium-iron phosphate battery, is now standard.
In a special unveiling event with top Honda amateur motocrossers during the AMA Amateur National Motocross Championship at Loretta Lynn’s Ranch, American Honda unveiled the all-new 2018 CRF250R. Designed and developed following the same “Absolute Holeshot” philosophy as the also completely overhauled CRF450R, the highly anticipated 250cc motocross model features a host of updates aimed at achieving maximum power and optimum handling.
“We’re excited to show this all-new, no-compromise model to our customers, and it’s appropriate that we do so with our family of Red Rider amateur motocrossers here at Loretta Lynn’s,” said Lee Edmunds, American Honda’s Manager of Motorcycle Marketing Communications. “The CRF450R has become the top-selling 450cc motocross model, and now that the CRF250R shares many of the same performance- focused updates, we’re confident it will enjoy similar success in the market and on racetracks everywhere.”
Here’s even more from the official 2018 CRF250R unveiling event, in the video below:
– Video | 2018 Honda CRF250R Unveiling –
What will you find below about the All-New 2018 CRF250R? Here’s a table of contents to help you find the specific information you may be looking for. Also, make sure to check back in a few hours as I have even more detailed cutaway pictures showcasing the new 2018 CRF250R DOHC engine plus loads more!
2018 CRF 250R Review Contents:
- 1. Quick overview (* for those of you in a hurry)
- 2. Introduction
- 3. Model overview
- 4. Key features
- Chassis / Frame
- 5. Technical specifications
* Quick Overview of 2018 CRF250R Details / Specs
For those of you that are in a hurry and don’t want to read the entire post going over all of the 2018 CRF250R vs 2017 CRF250R changes and all of the nitty-gritty detailed specs etc – Here’s a quick breakdown of everything you need to know about the all-new 2018 CRF250R from Honda:
2018 CRF250R Engine / Drivetrain (more details below)
In order to achieve their powerplant development goal of increased power (particularly at higher revs), engineers gave the 249cc engine an all-new dual-overhead-cam design, using a finger rocker arm with Diamond Like Coating (DLC). The titanium intake and exhaust valves are larger and have a higher lift and narrower angle, while the valve springs’ coils now have an oval cross-section to keep engine height as low as possible. The engine has more over-square dimensions, the cylinder offset has been increased, and the piston now features a bridge-box design–a first for a production Honda motocrosser. The intake system is now of a downdraft design for maximum efficiency, there are twin exhaust ports, and the dual exhaust features smoother routing and optimized pipe length. An electric starter is standard, powered by a small, lightweight lithium-iron phosphate battery. The end result of the copious changes is an engine with more power across the rev range, especially impressive at peak rpm.
- High-performance, 249cc single-cylinder engine with dual-overhead-cam design and higher rev limit.
- Cylinder offset changed from 4mm to 4.5mm for reduced friction.
- Finger rocker arm with Diamond Like Coating (DLC) maximizes valve lift while retaining a low engine height.
- Optimized bore and stroke, larger valves, and a narrower valve angle contribute to increased power and a higher redline.
- Oval-section coils on valve springs allow for increased valve lift while retaining a low engine height.
- Bridge-box piston converts combustion pressure to power with higher efficiency.
- Larger piston jet oil hole for weight reduction and reduced friction.
- New scavenging pump reduces pumping loss.
- Crankshaft with H-shape cross section enables weight reduction without sacrificing rigidity or inertial mass.
- Downdraft intake layout increases power and improves throttle response by reducing resistance, improving air-charging efficiency.
- Shorter intake length improves high rpm engine power and acceleration feeling.
- Dual exhaust ports improve air-charging efficiency.
- Compact dual muffler with more-gradual pipe bends smoothen exhaust flow.
- Electric-start standard for easy starting.
2018 CRF250R Chassis / Suspension (more details below)
The 2017 CRF450R set new standards for vehicle packaging in a motocross machine, with highly concentrated mass and a very low center of gravity; the 2018 CRF250R follows suit, with weight reduced overall but particularly up high and at the ends of the vehicle. Layout is slim and low, and the machine has superb rear-wheel traction but minimal front-end lift–ideal for strong starting and acceleration. The main spars of the new-generation, lighter aluminum frame are now tapered to optimize flex characteristics and provide good stability and reliable rider feedback, while a shorter wheelbase improves overall agility. An all-new titanium fuel tank and extruded subframe end save precious weight up high, a new Showa coil-spring fork contributes a plush suspension feel, and a lower, more centralized shock location improves stability. Bodywork mirrors the design of the CRF250R’s bigger brother in form and function, with a minimalist appearance and in-mold film graphics. Dunlop’s superb Geomax® MX3S tires are standard.
As a result of the engine and chassis updates, the 2018 CRF250R enjoys a three- percent improvement in start performance compared to its predecessor, along with improved acceleration and handling.
- Shorter wheelbase for lighter handling.
- Lower center of gravity reduces front-end lift and contributes to better acceleration performance.
- Reduced swingarm length improves rear-wheel traction
- Lightweight aluminum frame with tapered main spars improves rider feedback.
- Extruded-aluminum subframe brackets contribute to reduced weight and lower center of gravity.
- Titanium fuel tank contributes to reduced weight and lower center of gravity.
- Showa coil-spring fork enhances plush suspension feel.
- Lower, more centralized shock location improves stability.
- Dunlop Geomax MX3S tires for superior bump absorption and grip in wide variety of conditions.
- Smooth bodywork layout eases rider movement.
- In-mold film graphics for added durability.
- Carefully shaped front fender allows efficient air path to radiator.
– Video | 2018 Honda CRF250R Introduction –
Alright, now for those of you that want all of the detailed information about the completely revamped and redesigned 2018 CRF250R from Honda, here we go…
2. 2018 CRF250R Introduction
When it comes to competition it doesn’t get much tighter, or more committed than the MX2 class. And Honda’s CRF250R has consistently proved a worthy weapon for battle. It is a machine that has evolved over time, through increments and steps, into a base platform that the amateur MX enthusiast – as well as pro-racer – can get the most out of.
But the game moves fast and the 2018 CRF250R is making a giant leap, inheriting the Absolute Holeshot philosophy of the 2017 CRF450R. With its seventh generation frame, revised geometry and Showa suspension, evolution has been firmly replaced by revolution and it’s now armed with the exact same chassis as its CRF450R sibling plus a brand new DOHC engine.
Why? Top racers always want – and crucially can use – more power and the new CRF250R is designed purely around what Honda’s motocross / supercross racers require to do their job.
Of course with its switchable engine mapping and rider-focused ergonomics it’s still a motocrosser that the hobby rider can exploit to their individual level of ability. But the 2018 CRF250R’s performance parameters, in terms of output and handling ability, have been elevated with only one aim in mind. To put a winning machine into the hands of those that can win.
Mr Mikio Uchiyama, Large Project Leader (LPL) 2018 CRF250R:
“Our new CRF250R has been redesigned to achieve outstanding hole shot start acceleration AND much greater engine performance over a lap. We have replaced the Unicam power unit with a brand new DOHC engine that revs so much harder, and higher. It’s matched with our CRF450R chassis that improves handling and rear wheel grip. Developed with direct input from HRC to be the complete package, the 2018 CRF250R is a competitive, durable and formidable race machine.”
2018 CRF250R – “ABSOLUTE HOLESHOT!”
– Video | 2018 Honda CRF250R Review of Features / Specs –
3. Model Overview
The 2018 CRF250R leaves the 2017 CRF250R in its roost with a power-to-weight ration improvement of 5%. In a wheel-to-wheel test the new CRF250R is 3% faster from 0 – 32ft / 10m and 3.6% quicker over 98ft / 30m. That’s close to half a bike length, and a full bike length respectively.
Its DOHC engine, with over-square bore and stroke, bigger valves and revised inlet / exhaust setup makes a hefty 9% more horsepower up top, for far longer, with extended over-rev and higher redline. Out of the gate, and lap after lap, the 2018 CRF250R is built to pull out an advantage and cut lap times.
And the 2018 CRF250R’s new fully mass-centralized chassis – identical to the current 2018 CRF450R – can put the extra power to effective use, its geometry and lower center of gravity driving the rear tire into the ground harder. The new CRF250R also employs the same Showa 49mm steel-sprung front fork as the CRF450R offering familiar (and extensive) levels of adjustability.
Like the CRF450R, the CRF250R’s plastics outline neat aerodynamics and a smooth, organic shape giving the rider ample freedom to move. They also feature scratch-resistant film insert graphics, which deliver sharp visuals and a durable finish.
Like the 2018 CRF450R, the new CRF250R is fitted with an electric starter as standard equipment.
– Video | 2018 Honda CRF250R Overview of Specs / Features (Vital MX) –
4. Key Features
4.1 Engine | CRF250R
The 2018 CRF250R DOHC engine is a clean sheet design and has been built with the focus on top-end power for acceleration and drive, plus improved over-rev corner-to-corner. The simple facts: it makes 9% more peak power with a spread that delivers that power over a 2,000rpm higher range, and also features a 900rpm increase to the ‘redline’ figure.
And the dyno graphically tells the story. From 8,500rpm the 249.4cc engine simply takes off compared to the previous model and keeps building power and torque as the revs rise.
Central to the improved performance – which is all about much higher gas flow, in and out – is a revised bore and stroke of 79 x 50.9mm, with a 4.5mm cylinder offset to reduce friction (as opposed to 76.8 x 53.8mm, 4mm offset). This is a much more ‘over square’ layout, with bigger bore and shorter stroke which allows the use of larger titanium valves: 33mm inlet (which feature a neck shaped to reduce intake resistance) and 26mm exhaust (30.5mm/25mm).
Lift is also increased: 10.5mm inlet and 9.5mm exhaust (9.2mm/8.4mm) and the valve angle is more compact, going from 21.5° to 20.5°. The rocker arms feature Diamond Like Carbon (DLC) coating, a Nano-thin hard film that provides high wear resistance and lubricity; the valve springs themselves are now oval in section. The inlet valves are fed – via PGM-FI with 46mm throttle bore – by symmetrical straight-shot downdraft intakes, which are shorter for improved high rpm snap.
The new engine features twin exhaust ports, each of which has its own exhaust down pipe, with bends that radius gradually to smooth out gas flow. The twin mufflers are sited 24mm inward toward the center of the machine, to aid mass centralization.
Compression ratio goes up slightly from 13.8:1 to 13.9:1 but the piston shape is now a Bridged Box design – the first on a Honda MX machine. Its rigidity converts combustion pressure into high output efficiency and, despite the bore increase, the piston carries no extra mass. Four piston jet oil holes (rather than two) reduce friction and ensure optimized cooling.
The new H-Section crankshaft is 350g lighter while maintaining inertial mass, for response and stiffness, and rigidity. To make the engine as physically compact as possible the axis distance between the crank and balancer shaft is reduced by 0.5mm, and 1mm between the crank and primary gears. The cam chain is now on the right, to shorten the distance between the crankshaft and the mass of the Alternating Current Generator (ACG).
Incorporated into the CRF250R’s new engine is an electric starter motor, replacing the kickstarter. Located centrally (the new crankcase layout ensures all inertial masses are closer to the C of G, for improved handling), it drives the one-way clutch and idle gear via a press-fit torque limiter; its Lithium-ion battery is compact and weighs just 1.43 lbs. Engine weight with the electric starter added is increased by just 2.2 lbs.
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 – total oil capacity 1.32qt / 1250cm3 – as opposed to .89qt / 850cm3 engine and .79qt / 750cm3 gearbox of the previous design (1.69 qt / 1600cm3 in total).
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 has been simplified, shortened and 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. Lightweight water hoses are now 3mm, rather than 4mm in wall thickness.
While exactly the same physical size as before the clutch outer features a revised clutch basket. Delivering consistency in hard use it utilises differing friction material on the two outer plates. The clutch lever housing is also redesigned, simplified and lighter. The 5-speed gearbox is constructed from new, high-strength steel and is .44 lbs / 200g lighter; it also uses slightly shorter gear ratios for first and second, and the final drive ratio drops one tooth to 48T on the rear sprocket.
The engine stop switch and Engine Mode Select Button (EMSB) are incorporated into a small housing on the left side of the handlebar. Three maps are available to suit riding conditions and rider preference: Mode 1 (Standard), Mode 2 (Smooth) and Mode 3 (Aggressive). A small indicator light displays Mode selected.
On the right of the handlebar is the starter button. The resin slider of the throttle housing is now incorporated into the throttle cable itself, reducing load; a knurled nut adjusts free play.
4.2 Chassis | CRF250R
The 2018 CRF250R employs the same frame and suspension setup as the current CRF450R, with the same basic aims; connect the rider to the terrain with superlative feedback and gain rear wheel grip and drive through a rearward shift in weight bias, tied to a lower center of gravity.
Saving .74 lbs / 340g over the previous design the seventh-generation aluminum beam frame features tapered main spars with a carefully tuned balance between rigidity and flexibility, designed to deliver front-end stability plus a direct feel for traction.
Compared to the outgoing CRF250R design the chassis’ geometry markedly differs; wheelbase is 3mm shorter at 58.3 in / 1486mm and the distance between the swingarm pivot point and rear axle is 15mm shorter at 22.5 in / 573mm. Rake is set at 27.5° with trail of 4.6 in / 116mm. The C of G is .05 in / 1.4mm lower.
The rear subframe is now extruded aluminum (rather than forged) and is 20% lighter, aiding mass centralization. Seat height is .23 in / 6mm taller at 37.8 in / 957mm, with .19 in / 5mm more ground clearance at 12.9 in / 327mm. Wet weight (without fuel) is 227 lbs / 103.3kg, with fuel 238 lbs / 108.1kg.
The Showa SFF-TAC-Air front fork of the previous model has been replaced with a 49mm Showa USD coil-spring fork. Debuted on the current CRF450R it’s not an evolution of the older 48mm fork, but a version of the Showa kit fork supplied to MX race teams in the Japanese championship.
The cylinder has a 25mm diameter, the rod 14mm with the compression piston 39mm. As you’d expect from what is effectively full race-spec suspension the fork action is supple, smooth and always in control. It’s also fully adjustable.
With a top mount 39mm lower and located directly on the machine’s center line the fully adjustable Showa rear shock works the aluminum swingarm – .48 lbs / 220g lighter – through Pro-Link.
A 260mm wave-pattern disc delivers effective heat dissipation, power and feel from the two-piston brake caliper working it; a matching 240mm wave-pattern disc and single-piston caliper is at the rear. Lightweight aluminum rims, with directly attached spoke pattern layout reduce unsprung weight; the front is a 21 x 1.6in, the rear a 19 x 1.85in. Fitted as standard equipment are Dunlop’s GEOMAX MX3S tires, 80/100-21 front and 100/90-19 rear.
The new 2018 CRF250R also shares the CRF450R’s 1.6 gal / 6.3L titanium fuel tank, which at 2.2 lbs / 1039g weighs 1.1 lbs / 513g less than the plastic design it replaces. The loss of entire pound sat high on the machine contributes to the lower center of gravity, and the flattened tank cap and lower profile enables the rider to move forward easily.
Wearing plastics with smooth external lines to help the rider move easily the frontal area is also narrower; the front mudguard directs a more efficient funnel of air to the radiator. The bodywork also uses durable film inset graphics that cover a wide area with scratch resistant style.
5. Technical CRF250R Specs
|2018 CRF250R Specifications|
|Model||CRF250R (Model ID: CRF250RJ)|
|Engine Type||249cc liquid-cooled single-cylinder four-stroke|
|Valve Train||DOHC, four-valve; 33mm intake, titanium; 26mm exhaust, titanium|
|Bore x Stroke||79.0mm x 50.9mm|
|Induction||Programmed fuel-injection system (PGM-FI); 46mm throttle bore|
|Starter||Electric w/ lithium-iron-phosphate battery|
|Driveline||#520 chain; 13T/49T|
|Transmission||Constant-mesh 5-speed return; manual|
|Clutch||Multiplate wet (5 springs)|
|Front||49mm fully adjustable leading-axle inverted telescopic Showa SPG coil- spring fork; 12.0 in. travel|
|Rear||Pro-Link system; fully adjustable Showa single shock; 12.4 in. travel|
|Front||Single 260mm hydraulic disc|
|Rear||Single 240mm hydraulic disc|
|Front||Dunlop Geomax MX3S 80/100-21 w/ tube|
|Rear||Dunlop Geomax MX3S 100/90-19 w/ tube|
|Rake (Caster Angle)||27° 22’|
|Trail||116mm (4.6 in.)|
|Seat Height||37.8 in.|
|Ground Clearance||12.9 in.|
|Fuel Capacity||1.6 gal.|
|Curb Weight*||238 lbs.|
*Includes all standard equipment, required fluids and full tank of fuel—ready to ride. Meets current CARB and EPA off-road emissions standards