Two of the best from Honda
By TMX Archives on 27th Sep 07
THANKS to its virtually unlimitless funds and vast technology bank, not to mention the might of the HRC race department, Honda's motocross machines have always been at the cutting edge of motorcycle technology.
The list of developments that became standardmotocross issue which originated at Honda is a long one indeed and tothat you can now probably add Steering Dampers.
That's right, for the 2008, steering dampertechnology makes its appearance on a production motocross machine forthe first time when both the CRF250R and CRF450R arrive in dealershowrooms very soon.
In use since 2004 on factory Honda machines, firstin the US then on the GP circuit, the Honda Progressive Steering Damper(HPSD) has now been rolled out onto the production machines with theaim, says Honda, of not only assisting in straight-line handling andfront-wheel stability as is the case with after-market dampers butto also promote more aggressive, faster turning characteristics.
How big a deal is this? Well, where Honda leads,at least one of the other Japanese manufacturers follows, and as youread on you will discover that the HPSD really does seem to work verywell, so don't be surprised to see steering damper technology makingappearances elsewhere rather soon.
While confident that HPSD units usher in a new erafor Honda motocross machines and leave the 2008 CRF models at a levelabove the competition in terms of handling and stability, the companyhasn't held back and the biggest overhaul of the both the 450 and 250for three years has taken place.
As a result of the HPSD system improvingstability, the long-standing CRF450R and its smaller sibling bothreceive steeper steering-head geometry, moving from a 24mm off-set to22mm, for a more aggressive chassis feel, while the CRF450R alsoreceives new, stiffer suspension settings and a new Showa fork thatincludes a larger cartridge and oil piston for improved oil flow andless friction.
The CRF450R also receives a new tapered exhaustheader-pipe for improved low-end and mid-range power, a new multi-mapCDI unit adopted from the factory machines which provides specificmappings for each gear and thus boosts the torque and power outputsacross the board. The rev-limit is also increased by 50rpm to 11,270rpm.
A friction reducing coating has been added to theclutch basket and pressure plate to improve feel and clutch life, whilenew works style brake rotors have also been fitted to reduce unsprungweight.
The CRF250R, meanwhile, has been the focus ofsignificant engine modifications to boost the power output and thusbenefits from a new piston with increased 13.1:1 compression ratio, newcylinder head porting, lighter valve train components and and increasedrev-limit of 13,500rpm, new camshaft timing, a new exhaust system, andrevised carb settings.
The other big news, and it's not good I'm afraid,is that the longstanding CR125 and CR250 are no more. As part ofHonda's plans for an all four-stroke future, the trusty CR smokers havebeen consigned to the history books. It's a real shame but we've allknown it has been coming for a number of years now.
So with just the two four-strokes to ride, theEuropean press were invited along to the new Donington Park GP circuita couple of weeks back for the official launch.
JOHNNO WHITE:
SO 2008 is almost here and that can only mean one thing new bikes to test.
It's always a bind, honestly. It's a nightmareringing your sponsors up and asking for brand new kit, then having todrive to the newest GP circuit in the country, Donington Park, thenhaving to ride the latest bikes...what a shame for me hey?
This time round it was a chance to put my leg overthe new four-stroke offerings from Honda. There are no two-strokemodels anymore, they have finished production, so it was just the 2008CRF250R and CRF450R to put through their paces.
It was an interesting day because it was theEuropean launch and there were also quite a few GP stars there from thepast and present, including the now four-times world champ Dave Thorpehimself! I sat opposite him during lunch and considering he is such alegend in our sport he is a top bloke and a great role model for youngriders.
Anyway, enough of this nonsense. I have to go on abit so it looks like I've done loads of typing and then JD won't askfor more...
CRF250R
THE natural starting point was the CRF250R and in recent years I feel it has been playing catch-up a bit.
It seemed to make great strides forward in itsfirst couple of years, and its handling in particular has always beenright-up there at the top of the class, but its motor has never beenthe strongest and in the past couple of seasons it has been caught andpassed by more than one of its rivals.
For 2008 though, it seems Honda has really pushed the boat out to put the CRF250R right back up there.
Honda likes to state that it is always one stepahead of the pack and they are certainly the first manufacturer to fita steering damper on a motocross bike from the crate.
Yes that's right, the 2008 Honda range comesequip-ped with the Honda Progressive Steering Damper (HPSD) system thathas been in use on the factory bikes for a number of years. It's thebig USP of the CRF models for 2008 and it looks real factory too.
It mounts behind the number plate so you can'tactually see it unless you have a good nosey or you take the numberplate off, but on the track it seemed to work very well indeed.
For those of you who don't understand how itworks, I will try and explain. When you're going down a fast straightor through a fast corner with a lot of high speed bumps and you aregetting tired it is quite normal for the front-end to push and shakefrom side to side unless you have arms like Popeye. So, Honda hasfitted the damper to reduce this phemonenon. It's basically like a minishock-absorber for the steering system.
When you are in the paddock and you turn the barsslowly it doesn't seem to do that much but when you shake them back andforth quickly you can really feel the damper working so, when you're onthe track, it really becomes noticable.
It smoothens everything out, particularly on thefast choppy stuff and if you really go in to a corner hard, and thebumps and lumps that would ordinarily push the front-end away from youor cause you to get a bit of tank-slapper on, have noticeably lesseffect on the bike, and if you get out of shape the damper starts towork overtime, hence less scary moments on the track.
All this contributes to a bike that feelssignificantly more planted and stable, particularly at higher speeds,and, importantly, takes less energy to control, thus making it andeasier ride all round.
What is surprising is that this has been achieveddespite the fact that the front-end has been steepened by 2mm. This maynot sound a lot, but it has a huge impact on the geometry of amotorcycle and the result is a bike with a 2mm shorter wheelbase andsharper steering angle. In the past, this would have resulted in a bikethat turned faster but at the sacrifice of overall handling andstability, However, because of the addition of the steering damper,Honda has achieved the feat of getting a bike to turn faster andsharper whilst actually im-proving overall bike stability.
It's a big achievement and boosts rider confidencein the bike significantly, and I'm sure it won't be long before all theother Japanese manufacturers will be fitting one too. When you thinkabout it really, it's a bit of no-brainer, and does make you wonder whysteering damper technology hasn't been applied before.
As a result, the overall handling of the CRF250Rwas pretty damn good and a step-up again from what was already a sweethandling bike. It cornered very smoothly and always felt plantedentering and exiting, the seating position felt good and I found thebike was very easy to throw around. In fact, I didn't get out of shapeall day which isn't bad for me! Although I did have a bit of a scarymoment over the finish line tabletop but it is about 200 foot long slight exaggeration I know, but it is big.
The suspension was really good too, especially forslightly heavier riders than your usually featherweight schoolie. TheHSPD system allowed Honda to run slightly harder settings front andrear, and, while still very plush and supple off the bottom of thestroke, they were a bit firmer, which made a big difference for me andwill for heavier riders, as I wasn't ploughing through the stroke asquickly.
Ok, so the HPSD unit is great, onto the other stuff.>>
The overall look of the bike is pretty similar tolast year but with the ground-breaking (yeah right) new graphics asalways, and slightly modified rear fender and a new left side engineguard.
Power wise, the 2008 CRF250R was very impressivetoo. Although very useable, it's not exactly been the strongest motorout there over the past few years, but the 2008 model seems muchstronger than last year's bike which is great news.
Most noticeable was a much improved bottom-end. Ifound it to be very responsive out of the turns and a real pleasure toride, which is probably down to the new piston and 13.1:1 compressionratio as well as the new cylinder porting and lighter valve componentsthat help it rev out that bit further to 13,500 rpm. All the waythrough the rev-range though, the bike felt stronger and moreresponsive which is impressive.
To sum up, I think Honda are going to be back atthe front of the pack with their 2008 CRF250R, and cleverly, on Honda'sbehalf, I don't necessarily think it's be-cause it is loads better thanits rivals, it's not, although it is a contender for best all-roundbike in its class. I think it's going to be down to one little item,the HPSD steering damper. We all like to have the latest technology andthe Honda Progressive Steering Damper is definitely going to turn someheads in the paddock.
CRF450R
NEXT for me to swing my leg over was the daddy, the CRF450R.
IT seems like this bike has been round for an age now, and in fact it has, the first CRF450R came out in 2001.
I remember it well. I was racing a DRZ 400 in theBritish Four-stroke and MR Thumpercross champion-ship and rememberturning up at the first race of the season and the paddock being a seaof red. Nearly every lad in the paddock had bought a CRF450R that yearand boy were they fast, and as the years have gone by the CRF450 hasjust got better and better.
There have been handling problems sporadicallybe-cause of chassis changes but in general it has been a rock, alwaystopping the tables in magazine shoot-outs and dominating line-ups fromclubman races to GPs.
Anyway, looking round the 2008 450R it isvirtually identical to its little brother and adorned with the newplastics too and, in fact, it is only just short of 8kg heavier than the 250R.
Obviously, like the CRF250R, the CRF450R comesfitted with the HPSD unit too which, on the considerably more powerful450 machine, where unweighting of the front-end is more of an issue, isa bigger bonus.
I'll not go on about the workings of the dampertoo much because it's exactly the same principal as the CRF250R andyou've already read about its effect on the handling of the bike, but Iwould say everything that impressed with it on the 250F impressed me even more so on the CRF450R.
When you are really on the gas on the CRF450R, thefront-end has had a tendency to feel a little bit loose and light,which when big kickers and rough tracks were thrown into the mix couldgenerate a bit of head
-shake and front-end unstability, but the HPSD really helps to combat this and the front-end now feels rock solid.
It is also a lot easier to snap the bike aroundand throw it into corners too, thanks to the 2mm steeper front-endwhich results in an impressively nimble handler for a big 450. Myconfidence in the front-end of the CRF450R has increased significantly.
The power on this year's bike is improved again too, which is amazing really, considering how much grunt it already has.
There is a new tapered header pipe to improve lowto mid-range power and I have to be honest, the delivery was amazing.It's very strong indeed and continues to build all the way up to thevery top-end with impressive grunt.
The CRF450R also comes with a new multi-map CDIsystem with a transmission gear position sensor which helps the torquefeel stronger in first gear and produces a wider powerband in secondgear and a better stronger throttle response in the top-end torque ofthe last three gears and, out of the corners, I could feel just howmuch drive and torque the new model had. It physically pushes you backon the seat and just by riding the bike in prime of the torque it wasvery easy to get over the bigger jumps.
It is surely the strongest 450 motor on the marketand I realised how unfit I was, after just playing around for the lastfour years, very quickly.
Don't get me wrong, I totally enjoyed riding theCRF450R but I could only manage about five hard laps before I wasbreathing out of my...well you know what I mean!
As far as suspension was concerned, like itslittle brother, it is running a slightly stiffer set-up, but on some ofthe more polished-up corners and choppier sections I found thefront-end a little bit stiff or possibly over sprung for my liking. Iprefer a more progressive feel to the front-end and I didn't get muchfeeling from it. It's easily rectified, but perhaps Honda went a bittoo far this time. The rear end was fine, however, and trackedperfectly well all day.
In general, the CRF450R is again a great all roundbike. It's in its eighth year of production now but the CRF450R seemsto keep pushing on and improving every year, and although all fourJapanese manufacturers have a very good 450 of their own now, the CRFis still the bike to beat and will flood paddocks everywhere again.
SPECIFICATIONS
2008 model Honda CRF250R/ CRF450R
ENGINE
Type: Liquid-cooled four-valve SOHC single four-stroke
Displacement: 249.4/ 449 cc
Bore x Stroke: 78 x 52.2 mm/ 96 x 62.1 mm
Compression Ratio: 13.1 : 1/ 12 : 1
Max Power: 32kW @11,000 rpm/ 37.8kW @ 9,000 rpm
Max Torque: 29.3Nm @ 8,500 rpm/ 46.9Nm @ 7,000 rpm
Carburation: 40 mm (with TPS)/ 41 mm 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
Type: Semi-double cradle, aluminium twin-spar
SUSPENSION
Front: 47mm Showa invertedleading-axle twin-chamber cartridge-type telescopic fork with 16-step adjustable compresion and rebounddamping
Travel: 315 mm at axle
Rear: Pro-Link with Showadamper, adjustable low-speed (13-step) and high-speed (3.5- turn) compression and 17-step rebound damping
Travel: 313 mm/ 320 mm at axle
WHEELS
Front: 21 x 1.60 aluminium rim/ wire spoke
Rear: 19 x 1.85/ 19 x 2.15 aluminium rim/ wire spoke
TYRES
Front: 80/100 21 (51M)
Rear: 100/90 19 (57M)/ 110/90 19 (62M)
BRAKES
Front: 240 mm hydraulic disc with dual-piston calliper and sintered metal pads
Rear: 240 mm hydraulic disc with single-piston
DIMENSIONS
Length: 2,170 mm/ 2,189 mm
Width: 827 mm/ 825 mm
Height: 1,277 mm/ 1,283 mm
Wheelbase: 1,477 mm/ 1,489 mm
Seat Height: 965 mm/ 955 mm
Ground Clearance: 362 mm/ 340 mm
Weight: 101.2 kg/ 109 kg
Fuel Capacity: 7.3 litres/ 7.2 litres
Specification:
