450 vs 650 dirt or motard

[Slyder]

So I'm thinking when the time comes I'll buy a 450 of some sort, and hopefully have dirty wheels / tires as well as street so with a little work I can swap it back and forth. A friend keeps telling me 450's have a terrible power delivery and can't run with a 650. I've seen the 450's go at NHMS and they look stupid fast. He refuses to believe that, and can't be bothered with going to the track to actually watch a race. I've tried for years to get him to go.

So my friend keeps mentioning he wishes he could stuff an XR650 mill into a CRF450 frame. I keep asking why you'd need more than a 450.

Curious what others think. No racing, on or off road. He's tarding the XR650 for street riding duty. How would an off road only (CRF, RMZ, etc) 450 compare to the XR650 set up the same way?

[Doc]

I have a 450x that I am motarding. You can try it out if you like.

Mark has a 650 I believe. He tried to get me to buy one and know alot about them. I can't remember what he explained the pros and cons are but either way YOU will have to lower either one. (shortie)

[Kitt]

650 has great longeviy and lower maintenance than a jap mx 450 motor. If I tarded a 650, I'd want diff. suspension.

[FTMS]

I think the real question is are you running a 530 chain on it or a 520?????????

[Kitt]

I think there were 3 XR650's in the diablo challenge.

[Slyder]

Depends, 530 if I go with a turbo. 520 if not

Just curious how the two motors stack up, longevity would probably be the better way to go for a street ride.

Me? Lower one? Naw. If that was the case, the 1k would need to be lowered too. I growed up riding MX bikes, KX60 at first then on to an RM125...when I started riding the RM, both my feets were about 6-8 inches from the ground. A year or so ago I sat on a WR450 and a CRF450...I don't mind the seat height on those bikes at all really.

[Chippertheripper]

The bigger the motor, the less "flickable". That said, the water cooled 650's honda is making are monster torque machines. I think about the same hp as the 450r's. The only thing I've heard bad about them is the early ones were prone to overheating. See thumpertalk for more info on this.

[Kurlon]

450s are lighter and have similar if not higher peak HP numbers compared to the XR650. The XR650 has crazy torque and longer maint intervals. For road racing I'd go with the 450 if I was in it to win it, just don't know if you could get an XR650 light enough to do the deed.

[typeone]

funny you guys mention 'crazy torque'. my friend has a street 'tarded XR650R, he also had a CRF450 dirty (which he said was fast/powerful in the dirt)...

on street rides, while he absolutely loves the XR, he constantly mentions the 'pretty mellow' power output of the 650. i can ask what his gearing is but i know it cruises well, isn't buzzy, does quick tight backroads really well, but says it's hard to wheelie and doesn't really get-up-and-go like he expected it to. the guy that built it did everything right so it's definitely set up correctly. piped, jetted, geared, etc and motor is mint too (had less than 300mi on it i think).

it has power, looks and sounds great, but i think he was expecting more out of the 650 motor, especially torque. i bet weight has a lot to do with it, both the bike and him. i'm about 175lbs and he's a little bigger. even though the suspension is set up pretty well, it needs more work. he talks about a lot of 'see-saw' action, which is kind of a motard trait if you still want semi-plush on the fireroads and trails.

longevity and ease of maintenance were real big reasons for his decision to go with the XR (he was also looking at CRFs, SXV's and Husky 610s). a wash, an oil change, some chain maint. and he's always ready to ride while i'm stuck wrenching and spending $$$.

i agree, ThumperTalk and SupermotoJunkie would be great places to read more input. i havent ridden his XR so i can't compare to my SXV. he always wants to trade but i'm afraid it will blow up the one time i let someone else ride it. hahaa!

anyway... some coins for ya

[Kurlon]

The extra 100+ lbs of fat it's toting XR650 vs CRF450R might have a tiny bit to do with the perceived lack of 'poke' in that lump.

[seth399]

I think your friend is crazy haha. Like Kurlon said, the weight/peak power is going to be more fun/race friendly on the 450 compared to a 650 boat

[typeone]

woah, 100+? i didnt know it was that much, havent read specs

[typeone]

I think your friend is crazy haha. Like Kurlon said, the weight/peak power is going to be more fun/race friendly on the 450 compared to a 650 boat

right, it is a boat... but why the 'crazy torque' comments? just from motor specs? i ask this because thats all he read too... torque motor. i had an XR250R back in the day = HEAVY

EDIT: you mean the OPs friend. carry on...

[FTMS]

Did he build a XR650L or a XR650R?

[seth399]

right, it is a boat... but why the 'crazy torque' comments? just from motor specs? i ask this because thats all he read too... torque motor. i had an XR250R back in the day = HEAVY

EDIT: you mean the OPs friend. carry on...

oops, ya I meant the op

[Chippertheripper]

I make the reference as to the way the thing tractors along in the woods.

[typeone]

The extra 100+ lbs of fat it's toting XR650 vs CRF450R might have a tiny bit to do with the perceived lack of 'poke' in that lump.

Dry weights, I didn't think it was that drastic but it's still extra weight...

XR650R = 276.9 lbs
CRF450 = 240.3 lbs

[Kurlon]

Dry weights, I didn't think it was that drastic but it's still extra weight...

XR650R = 276.9 lbs
CRF450 = 240.3 lbs

I was looking at the specs on the XR650L, 350lbs wet and ready.

[gregp]

If you want to go fast, get a 450. The newer over-square motor designs are quick revving and, as others have said, they produce just as much power, or more, than a close to stock 600-650. Less rotating mass means quicker handling/direction changes.
On the other hand, if you are going to be spending most of your time at "street" speeds, and use the bike for commuting and local running around, the longer stroke 600-650's are probably the way to go. They require much less maintenance, and are more user friendly in that environment.
I just sold my DRZ400S, which is not really considered a "high performance" bike, but it still had a short stroke design. While it was fine for most of the trail riding and street use I doled out to it, I purchased a pristine DR650 to replace it. The 650 is much more suited to long pavement droning, and still allows a spirited riding pace with no mods at all. I pay the price as soon as the tires touch dirt. The weight and cumbersome handling of the 650 keep the pace to a crawl. My 650 is lowered, and very pretty, so I do not want to crash - at all. The 400 had been through a lot, and I hit the ground many times with it, but it had an IMS tank. In over 5 years of ownership, I never once had to work on the DRZ. That is impressive, and I do not know if any of the higher strung 450's could make that claim, given similar treatment.
So, I guess that in simple terms, Performance = Maintenance. No getting around that when you are dealing with relatively small displacement singles.

[typeone]

I was looking at the specs on the XR650L, 350lbs wet and ready.

got it. yikes (wheres a fat guy smilie)

[gregp]

BTW - Big difference between an XR650L and an XR650R - motor wise and chassis wise. A 'tarded 650R would most likely be a hoot to ride, but you'll have to kick it to life.

[Slyder]

It's a 650R he's tarding out.

Good info tho, sounds like if I want a 450 I will have to tear it down and rebuild it every time I kick the damn thing over tho

[seth399]

my crf450 was trouble free for 2009 season

[Neytiri]

Could get the 450 with a big bore kit , full exhaust, PCV, High compression piston setup and you'll be balling.

[Slyder]

Could get the 450 with a big bore kit , full exhaust, PCV, High compression piston setup and you'll be balling.

That sounds like something I'd want to do. I can't imagine the reliability on that would be too great though? Not really wanting to have to rebuild it every X number of hours. If the 450's were more reliable I'd definitely have an RMZ, and in VT I guess it's cake to register even with an "off-road only" cert. of origin.

I guess if I want a 450 someday I'll have to hope the reliability improves or I'll have to get use to tinkering and spending some coin.