Hondas 2007 four-stroke range
By TMX Archives on 23rd Aug 06
SUBTLE refinements, rather than major developments or re-designs, has been the name of the game at Honda's R&D department over the past 12 months.
As the biggest and most successful motorcycle manufacturer in history, exciting and potentially era-defining developments have been Honda's forte for years, from the development of the aluminium twin-spar frame in 1997 to last year's dual-silencer CRF250R, and Electronic Fuel Injection in the near future it seems.
But for its 2007 range of CRF four-stroke machines, Honda has taken a more conservative approach and releases the award winning CRF450R and CRF250R motocross weapons, and CRF450X and CRF250X enduro spec machines with a small but significant number of minor modifications and tweaks in both the engine and chassis departments of both model ranges to further improve the power output, rideability and reliability of all the bikes and ensure that the Honda name remains synonymous with class-leading performance and quality.
Launched to the European off-road press at the superb Honda Park facility, near Mol, Belgium, the day after the recent Namur Grand Prix, the 2007 Honda CRF range may not be the most exciting or ground-breaking on the track next season, but as T+MX News found out, Honda has upped its game just that little bit more once again and the bikes continue to set a benchmark of on-track performance and build-quality that its competition aspire to.
Sadly, for two-stroke afficionados, however, the final nails in the coffin of the legendary CR125R and CR250R machines appear to be very close to being banged into place as it was announced during the technical presentation that both models remain unchanged for the third consecutive year and no models would be available to ride during the test. The future for Honda it seems is four-stroke only, unfortunately, some would say.
CRF450R...
THERE are few superlatives left to describe quite how good a motorcyle the CRF450R is that have not already been used since its inception in 2002. In that time it has consistently topped magazine shoot-outs, taken Grand Prix, AMA motocross and supercross victories, numerous domestic championships, and at any race meeting across the globe from AMCA level to international it is tellingly proliferous.
The combination of class-leading performance and Honda's legendary build quality won fans from the very beginning and with the CRF450R seeing improvments each year since, it has remained the class benchmark. This, despite the increasingly strong competition from its rivals in recent years, and the relatively minor changes to the 2007 model, which focus primarily on smoothing-off the power delivery yet further and centralising mass for a more stable, responsive chassis, ensures that the 2007 version of the CRF450 remains a winner.
Engine-wise, the CRF450R benefits from smaller exhaust valves to improve gas flow (to smooth-off power delivery further), new ingnition mapping, new accelerator pump in the carb for improved throttle response, a lighter, more compact decompression system and, finally, a strengthened clutch basket and clutch centre for improved durability.
Leading the way in chassis modifications is a new sub-frame design which allows the silencer to be mounted closer to the engine block and leads to improved mass centralisation and machine stability.
The front suspension also receives attention and arrives with new valving for improved bump-absorption, while teamed with this is a new front-brake master cylinder that improves braking power by a claimed 15 percent and a new Dunlop 742FA tyre. A new one-piece throttle cover and lighter rear chain-guide, which are rolled out to the entire range, completes the developments.
I, personally, felt that Honda made big steps forward to improve the front end stability, overall handling, and smoothing-off of the potent power of the CRF450 this season and after a couple of laps of the Honda Park I was pleasantly surprised to find that the Honda R&D guys had managed to improve the bike in all these areas once again.
The ergonomics and riding position of the Hondas have been the most neutral, natural and comfortable on the motocross market, I think, for the past few seasons and the new sub-frame does not alter this, but by moving the silcencer further forward, Honda has made the CRF450 feel just that bit more centred and balanced. It is not a huge improvement by any stretch of the imagination but, over last year's, the bike feels as if the bulk of the weight is just a bit more centralised and as such is slightly more stable and manouverable out on the track all round, but particulary in rougher, sweeping corners. As a result, you feel more confident in what the bike is doing underneath you, giving the rider more confidence and allowing them to focus more on the track.
The new front suspension valving again is not massively different or improved, but is, I feel, a bit more supple through the early part of the stroke making it better in braking bumps and choppy sections, and teamed with the other handling benefits delivered by the new sub-frame and exhaust mountings it further improves the overall stability and control of the bike, making it more rider friendly, nimble and generally just a slightly more managable and enjoyable ride.
Rideability and smoother power have been the watch-words for all the big 450s over the past couple of seasons and the 2007 CRF450 has followed this line again, with the minor tweaks to the exhaust valves, carb and ignition further smoothing-off the power delivery over 2006 to make the bike even more rideable and user friendly for riders right across the board, which can only be a good thing.
The once fiery transition from low-end to mid-range is long gone, replaced with an incredibly user-friendly, smooth transition that belies the actual power the motor is putting out and enables riders to make better use of the bike's ability for longer periods of time. With the bike being just that bit smoother it leaves room for the rider to be more agressive and ride the bike harder without fear of repurcussions or the bike wearing them out, and combined with the more stable handling the smoother power creates a 450 that is begining to feel lighter, more controllable and increasingly like a 250F in its personality.
All in all, the '07 CRF450R is not the most radical or exciting 450 on the market this year, but it is probably still the best. Using its vast resources and knowledge, Honda has done just enough to make sure the bike has improved once again in areas that really matter to riders.
Faster, smoother, better handling, what more do you want?
SPECIFICATIONS 2007 Honda CRF450R
ENGINE
Type: Liquid-cooled four-stroke four-valve
SOHC single
Displacement: 449cc
Bore x Stroke: 96 x 62.1mm
Compression Ratio: 12 : 1
Max Power: 38.5kW @ 9,000rpm
Max Torque: 47.2kW @ 7,000rpm
Carburation: 40mm Keihin FCR flat-slide carburettor
Ignition: Computer-controlled digital capacitor
discharge with electronic advance
Starter: Primary kick
Transmission: 5-speed
Final Drive: #520 roller chain
CHASSIS
Frame: Semi-double cradle, aluminium twin-spar
SUSPENSION
Front: 47mm Showa inverted leading-axle
twin-chamber cartridge type telescopic
fork with 16-step adjustable compression
and rebound damping
Travel: 315mm
Rear: Pro-Link with Showa damper,
adjustable low-speed (13-step), high-
speed (3.5-turn) compression and 17
step rebound damping
Travel: 320mm
WHEELS
Front: 21 x 1.60 aluminium rim/ wire spoke
Rear: 19 x 2.15 aluminium rim/ wire spoke
TYRES
Front: 80/100-21 51M
Rear: 110/90-19 62M
BRAKES
Front: 240mm hydraulic disc with dual-piston
calliper and sintered metal pads
Rear: 240mm hydraulic disc with single-piston
calliper and sintered metal pads
DIMENSIONS
Length: 2,191mm
Width: 825mm
Height: 1,262mm
Wheelbase: 1,491mm
Seat Height: 955mm
Ground Clearance: 340mm
Dry Weight: 103.2kg
Kerb Weight: 108.7kg
Fuel Capacity: 7.2 litres
CRF250R...
BY comparison to its bigger sibling, the CRF250R should be much improved in its engine performance and power output thanks to some significant modifications including a new camshaft and cylinder-head porting, intake valves, crankcase venting, exhaust header, revised ignition mapping with 13,370pm rev-limiter and the new accelerator pump in the carb. However, I was left feeling a little underwhelmed by these changes.
This is not to say that the CRF250R is a bad bike, it is probably the most complete package in the class in my opinion, and definitely has the best chassis, but with hugely powerful competition in the shape of the KTM 250SX-F and new motors from Kawasaki and Suzuki just released or on the way it is just that I was expecting a bit more from these modifications.
Perhaps I expected too much, but while the top-end power has indeed been increased and the bike pulls just that bit longer in each gear I found no discernable power increase in the low to mid-range, which personally I think there is room for without damaging the machine's rideability and mass appeal.
The motor as a whole is super-smooth and free-revving, incredibly rider-friendly and responsive, with enough power for all but the very best riders, however, so these grumbles are minor and do not detract from the overall performance of the motor.
It is still a very competitive machine and the easiest bike in its class to get on with and get the most out of, especially teamed with the superb chassis that the CRF250R has.
Undoubtedly, the chassis stability and impecable handling of the CRF250R is the most impressive thing about the bike to me. I don't think there is a more planted, sharper or more responsive bike on the market and the whole set up makes the bike feel so light and nimble that you can't help but feel comfortable and confident with the bike almost instantly.
The chassis is incredibly well balanced and tracks superbly no matter what you throw at it or where you point it and the general feeling of lightness and nimbleness make fast changes of direction and jumping and absolute doddle. The re-valved front suspension improves the handling even further, particularly in the choppy stuff and further adds to the overall performance of the chassis just that bit more, helping the bike to remain at the top of the tree chassis-wise.
All-in-all the CRF250R is a phenomenal piece of engineering that combines a solid, if unremarkable motor with impecable handling to produce a strong all round perfromer that is once again going to be hard to beat.
SPECIFICATIONS 2007 Honda CRF250R
ENGINE
Type: Liquid-cooled four-stroke four-valve
SOHC single
Displacement: 249.4cc
Bore x Stroke: 78 x 52.2mm
Compression Ratio: 12.9:1
Max Power: 32kW @ 11,000rpm
Max Torque: 29.3kW @ 8,5000rpm
Carburation: 40mm Keihin FCR flat slide carburettor
Ignition: Computer-controlled digital capacitor
discharge with electronic advance
Starter: Primary kick
Transmission: 5-speed
Final Drive: #520 roller chain
CHASSIS
Frame: Semi-double cradle, aluminium twin-spar
SUSPENSION
Front: 47mm Showa inverted leading-axle
twin-chamber cartridge type telescopic
fork with 16-step adjustable compression
and rebound damping
Travel: 315mm
Rear: Pro-Link with single Showa damper,
adjustable low-speed (13-step), high-
speed (3.5 turn) compression and 17
step rebound damping
Travel: 313mm
WHEELS
Front: 21 x 1.60 aluminium rim/ wire spoke
Rear: 19 x 1.85 aluminium rim/ wire spoke
TYRES
Front: 80/100-21 51M
Rear: 100/90-19 57M
BRAKES
Front: 240mm x 3mm hydraulic disc with dual
piston calliper and sintered metal pads
Rear: 240mm x 4mm hydraulic disc with single
piston calliper and sintered metal pads
DIMENSIONS
Length: 2,172mm
Width: 827mm
Height: 1,277mm
Wheelbase: 1,479mm
Seat Height: 965mm
Ground Clearance: 361mm
Dry Weight: 93.2kg
Kerb Weight: 101kg
Fuel Capacity: 7.3 litres
CRF450X...
WITH T+MX News' resident enduroist, Jonty Edmunds, absent from the test it was left to me to give the CRF450X and CRF250X enduro machines a good going over in the tight little woodland enduro course laid on by the Honda Park staff.
As I am far from an enduro specialist, this is not a fully comprehensive test of the X models and should not be taken a such, more of a brief rundown of what's new for 2007 for the 450 and 250X machines and my initial opinions on the bikes pending a more comprehensive test from our enduro test team at a later date.
The flagship CRF450X is effectively unchanged from the current model, benefitting only from a new accelerator pump and linkage in the carburettor for improved throttle response, the new one-piece throttle cover that adorns the entire range and a lighter new rear chain guide, and as such its performance remains on a par with the 2006 machine.
Personally, I found no discernible improvement in the throttle response from the new accelerator pump, but with the loose, dry sand on the enduro trail, feedback from the rear tyre was limited. The bike, however, remains an impressive all-rounder which will appeal to everyone from Sunday afternoon trail riders to serious enduro competitors, thanks to its broad, useable spread of power and steady, reliable handling characteristics out on the going.
The bike is equally comfortable labouring along open tracks on the torque as it is being revved and ridden hard in a special test type situation, although the tight confines of test track meant it was not really possible to get the bike really wound-up and motoring, and the comfortable, neutral ergonomics and typically Honda-like robust handling make for a bike that, although not the sharpest and most nimble on the market, is rock-solid and very controllable.
The CRF450X is not the lightest bike however, and my only complaint would be that in the slow, tight, wooded sections the bike felt a little heavy and sluggish, making you work hard to keep everything flowing smoothly.
SPECIFICATIONS 2007 Honda CRF450X
ENGINE
Type: Liquid-cooled four-stroke four-valve
SOHC single
Displacement: 449cc
Bore x Stroke: 96 x 62mm
Compression Ratio: 12 : 1
Max Power: 36.2kW @ 7,500rpm
Max Torque: 46.8Nm @ 7,000rpm
Carburation: 40mm Keihin FCR flat-slide carburettor
with throttle position sensor (TPS)
Ignition: Computer-controlled digital capacitor
discharge with electronic advance and
lighting coil
Starter: Electric/ Primary kick
Transmission: 5-speed
Final Drive: #520 T-ring sealed chain
CHASSIS
Frame: Semi-double cradle, aluminium twin-spar
SUSPENSION
Front: 47mm Showa inverted leading-axle
twin-chamber cartridge type telescopic
fork with 16-step adjustable compression
and rebound damping
Travel: 315mm
Rear: Pro-Link with Showa damper,
adjustable low-speed (13-step), high
speed (3.5 turn) compression and 17
step rebound damping
Travel: 315mm
WHEELS
Front: Aluminium rim/ wire spoke
Rear: Aluminium rim/ wire spoke
TYRES
Front: 80/100-21 51M
Rear: 110/100-18 62M
BRAKES
Front: 240 x 3mm hydraulic disc with dual-piston
calliper and sintered metal pads
Rear: 240 x 4mm hydraulic disc with single
piston calliper and sintered metal pads
DIMENSIONS
Length: 2,176mm
Width: 825mm
Height: 1,254mm
Wheelbase: 1,478mm
Seat Height: 963mm
Ground Clearance: 348mm
Dry Weight: 115.7kg
Kerb Weight: 122.6kg
Fuel Capacity: 8.3 litres
CRF250X...
BY comparison to its bigger brother, the CRF250X receives a myriad of developments to both the engine and chassis for increased performance and endurance and out on track it is a noticably imporved machine over the 2006 model.
Taking its cue from the developments to the CRF250R on which it is based, the CRF250X benefits from adopting the same piston and rings as used on the 'R' version, new cylinder head porting, a revised ignition mapping and stronger clutch basket and centre for improved durability, as well as recieving a new lighter front hub and the same one-piece throttle housing and lighter rear chain guide as the 450X.
The aim of these developments was to produce a more free revving, responsive and powerful machine and once out on the track it was immediately noticeable that Honda's engineers have achieved just that.
The thing that I liked most about the CRF250X over the past couple of years was that its smooth, torquey power delivery made it a great bike for slower speed riding and more trail-riding orientated situations, and thus perfectly suited to Clubman level and fun riders. However, in faster going and when you really pushed the bike hard, it was a little too docile and did not really rev-out enough.
Thanks to the new piston, porting and ignition mapping though, the 2007 model manages to rev more freely right off the bottom-end and produce an Expert-pleasing increased top-end power and over-rev whilst retaining that user-friendly bottom-end and mid-range torque, making it a more potent and competitive performer all round. Another big benefit the increased top-end power and the free-revving motor has, is that you can hold a gear longer and don't have to work the gearbox so hard to keep the bike singing, thus giving you more time to focus on just attacking the course and posting faster test times and conserving energy.
Like the 450X, the handling and the bike's chassis performance remains steady and predictable, neither particularly outstanding nor drastically underperforming in any area, although it does perform in slow, tight sections better than its big brother, but to me the bike is a bit more suited to fun riders than serious enduro racers.
So there we have it, the 2007 Honda range. A tweak here, a tweak there and still right at the top of its game. What else do you expect?
Excitement? Best keep your eyes and ears open then, Honda has something really big up its sleeve!
SPECIFICATIONS 2007 Honda CRF250X
ENGINE
Type: Liquid-cooled four-stroke four-valve
SOHC single
Displacement: 249.4cc
Bore x Stroke: 78 x 52.2mm
Compression Ratio: 12.9:1
Max Power: 21.9kW @ 9,000rpm
Max Torque: 24.2kW @ 8,000rpm
Carburation: 37mm Keihin FCR flat slide carburettor
with throttle position sensor (TPS)
Ignition: System Computer-controlled digital
capacitor discharge with electronic
advance and lighting coil
Starter: Electric / Primary kick
Transmission: 5-speed
Final Drive: #520 T-ring roller chain
CHASSIS
Frame: Type Semi-double cradle, aluminium
twin-spar
SUSPENSION
Front: 47mm inverted Showa leading-axle
twin-chamber cartridge type telescopic
fork with 16-step adjustable compression
and rebound damping
Travel: 280mm
Rear: Pro-Link with single Showa damper,
adjustable low-speed (13-step), high
speed (3.5 turn) compression and 17
step rebound damping
Travel: 312mm
WHEELS
Front: Aluminium rim/ wire spoke
Rear: Aluminium rim/ wire spoke
TYRE
Front: 90/90-21 M/C 54R
Rear: 120/90-18 M/C 65R
BRAKES
Front: 240 x 3mm hydraulic disc with dual-piston
calliper and sintered metal pads
Rear: 240 x 4mm hydraulic disc with single
piston calliper and sintered metal pads
DIMENSIONS
Length: 2,174mm
Width: 827mm
Height: 1,261mm
Wheelbase: 1,481mm
Seat Height: 958mm
Ground Clearance: 346mm
Dry Weight: 106kg
Kerb Weight: 114.8kg
Fuel Capacity: 8.3 litres (1.5 litre reserve).
Specification:
