Constant speed WR450F?


15 replies to this topic
  • Dazza83

Posted August 31, 2006 - 03:18 AM

#1

Hey guys,

I was speaking with a dealer about the WR450F and he said, like the sticker says, that its not designed for highway use... fair enough, and he also said that you shouldn't ride it at constant high speed or high RPM.

My question is, what is the worst case scenario should one keep the bike at a high RPM and what is the maximum speed do you think one could get away with if they were to sit on it constantly for 20 mins or so?

Apparently the engine is designed to vary in revs heaps, but what would/could be the problem if we revved them constantly?

Has anyone taken them for a constant high speed burst and had any drama's or has anyone had any problems with this?

Cheers guys,
Thanks
Daz.

  • 89TRX350RX

Posted August 31, 2006 - 05:22 AM

#2

My '02 is street legal here in Canada... I run a 15 tooth on the front and a stock rear sprocket. I run it all around town with the occassional run down the hwy at 90-100kph. No problems yet! I've got 1600kms on it so far this summer...

Good luck!

I'm sure others will chime in!

  • Alley Cat

Posted August 31, 2006 - 05:37 AM

#3

Hey guys,

I was speaking with a dealer about the WR450F and he said, like the sticker says, that its not designed for highway use... fair enough, and he also said that you shouldn't ride it at constant high speed or high RPM.

My question is, what is the worst case scenario should one keep the bike at a high RPM and what is the maximum speed do you think one could get away with if they were to sit on it constantly for 20 mins or so?

Apparently the engine is designed to vary in revs heaps, but what would/could be the problem if we revved them constantly?

Has anyone taken them for a constant high speed burst and had any drama's or has anyone had any problems with this?

Cheers guys,
Thanks
Daz.

Hey Daz, Up in the NT mate, lots of high speed stuff here!!! When you say high speed, do you mean full throttle? I venture over 150km/h just about every ride (depends who's with me), I got 14/48 gearing. Tops out at 170 - 175km/h. If all I was doing was high speed stuff, I would go back to 15/50.

It is the high rpm that wears things out. Saying that, I got ~5000kms on my '05 now, but it is due for some new rings now. Just trying to justify money for bigbore kit at the moment, and this is helping.........

Doing this type of riding, I keep oil changes to every 5hrs (motul 5100), and keep a regular check on the valve clearances. Mine haven't moved yet.

The older models used to have 5th gear go in them, but that seems to be fixed from '04 on.

May I suggest you run the main jet slightly on the rich side too. Helps keep things cool.

  • Audun

Posted August 31, 2006 - 05:40 AM

#4

Had a husebarg 650 before. I used it everyday to school job and friends.. even during winter(-5 - -30 degrees celsius).. And there was no problem as long as i kept to the service intervals..

But to put it some other way.. if u run at high rpm.. lets say for 75% or more og max rev, it would be like riding my Yamaha R6 at 13000 rpms or more..(both as a rpm comparison and power comparison since the R6 gives little power at low rpm). This is clearly not desirable.. but change oil often, use high quality oil. Im about to change my sprockets so i kan go about 80 kmp at low rpms(<50% of maximum) with my 450.. I have to sets with chain and sprockets.. so its easy to cahnge between road and offroad use..

  • odonnks

Posted August 31, 2006 - 06:16 AM

#5

On any machine, the higher the RPM,s the greater the wear rate.

My greater concern would be the lack of cush-drive. W/O cush-drive the drive train could see much sharper load changes since there is allot less tire slippage on street compared to dirt.
These bikes are all made for off road competition and the mfg's have shaved the internals as much as possibleto save weight. Add greater traction and agressive throttle or shifting and component wear (tranny gears, chain, sprocket, conrod bearings, clutch, etc) will increase fast.
I make an effort to not 'hammer' on the bike when traction is high like on the street.

  • nitronaf

Posted August 31, 2006 - 11:09 AM

#6

i commute on my supermoto 300 - 400km per week
seems fine
longest ive held 130 - 160kmh was about 45minutes
done about 8000km on my 06 all good

PS commuting on a WR gives u an a$$ of steel

  • Dazza83

Posted September 01, 2006 - 12:11 AM

#7

Thanks for replies guys,

I was just told not to keep a constant RPM, especially higher up the rev-range as it is apparently bad for them. Theoretically what would be the drama's with this? simply overheating??

And I meant to ask, how much would a cush-drive be to install into the bike? am I looking at a fair bit of dosh and stuffing about? I plan to commute on the bike regularly, so it will see probably see a fair bit of on-road stuff (60% probably), and of course, the off-road stuff.

Having a WR and not taking it off road is like having a meat pie without tomato sauce - its just not on!!

Cheers,
Daz.

  • uncleroby

Posted September 01, 2006 - 01:28 AM

#8

I apologize for my poor technical english.

The problems are two:

1) The lubrification: 1 liter of oil may be not enough to lubricate the engine parts. When you drive at high speed the whole oil is circulating and you have no reserve in case you need extra.

2) All the motor with one piston are not balanced and they transfer all the strenghts to the engine parts creating vibrations.
The counter shaft helps but do not eliminates them.
At high rpm such high frequency vibration are very harmful for the engine.

3) Riding at constant speed may create resonance.

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  • bergermeister

Posted September 01, 2006 - 10:54 AM

#9

Hey mate,

I wouldn't be too concerned about the cush drive if you are running knobbed tyres. If you are running motard style tyres you should consider it though. The knobs will soak up the added shock from the high traction surface. I have used my Husaberg FE650 and WR250F as commuters with no worries. You definately don't want to get sloppy with your oil changes though. I also made a point of punching the throttle whenever I could to vary the revs a little.

  • windaddiction

Posted September 01, 2006 - 11:17 AM

#10

um I rode my motarded all summer with no cush drive, the only bad part was the surging.... like the bike had only 2 thortle postions that it liked wide open and closed lol. But I have had no problems never even overheated sitting in rush hour traiffic.

  • dirtysouth

Posted September 01, 2006 - 11:21 AM

#11

Dude I have been riding daily for nearly a year now and as long as you change out your oil bout every 600 the only trouble you will have is vibration. Stuff falls off of my bike here and there if I don't look over it every now and then...main things are sprocket bolts. Just feel around now and then and you would be golden.

As far as motors are concerned..the valves may need adjusting with alot of high revving but I can honestly say that these motors are great. Plus, if your ridin highways you'll always find a little cut through or country road and won't be able to help yourself from floggin around through those places. I don't like long straight shots. My longest truck on road surface was from Birmingham AL to Mobile AL (250 +- mi)....rode county roads at around 60-65 mph mostly and had no troubles. Just had to stop every time I saw a gas station and fill up cuz I didn't know if I was gonna see another one.... :thumbsup:

  • bluemax250

Posted September 01, 2006 - 01:05 PM

#12

Just as a reference, at the piston speed of 3500 feet per minute, the WR450 is going about 70 - 75 MPH with stock gearing.
3500 fpm is a theoretical "maximum" piston speed for longevity. (Piston airplane engines are built to run at or under this speed.)
From the engine's point of view, you should be able to run 65 all day.
However, the rest of the bike is a dirt bike, remember. I don't know if I would want to be riding any faster than that on the road, on a dirt-sikkle. Enjoy.

  • simon@vic

Posted September 01, 2006 - 04:48 PM

#13

high rpms all day is fine if you have good clean oil in it!!!!
and a clean air filter/ proper jetting!

  • Dazza83

Posted September 01, 2006 - 05:24 PM

#14

Thanks everyone, the advice has been very much appreciated.

I'm still tossing up options but the WR450F seems to be a worthy contender, something I've researching on a fair bit.

Whatever I choose, I'll be looking to get one by the end of September.

Thanks again
Daz.

  • PfM

Posted September 02, 2006 - 05:59 AM

#15

Has anyone else had surging problems at low throttle/constant speed on the road ?
I had lots of problems with this on my DRZ, but some jetting changes pretty much eliminated it.

Still considering WR...

Cheers

  • chrispy1202

Posted September 04, 2006 - 04:13 PM

#16

Last fall i bought a '00 DRZ 400E and put about 3500 km on it with no problems, except not enough juice (on/off road). This spring I bought an
'03 WR450 and have put about 5000+km on it (as much dirt as possible). I need to look at the valves shortly again, but other than that i have had zero problems except wiping that sh#t eating grin off of my face. :thumbsup: I have the trailtech endurance computer on my bike and am running a 14/50, 15/50(off road), 15/42(highway) and am getting a max top speed of 145km/h. Wouldn't suggest the 15/42 as it is tough on the motor in 5th. will be going to a 15/46 or 45 soon. I put on the 6.6 gallon tank and can ride until my butts too sore to ride anymore. Keep the oil clean and the air filter clean. Don't notice any surging problem, cause it's allways pulling hard. Eats lots of tires (trackmaster 2), 3 so far this year. need to look at other tire options.
chris.




 
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