Does a 4 spd have a wider ratio tranny than a 5 or 6 speed?

[mikesbaron]

Just always wondered if the 4 speed RMZ450s and Kawis would have to have a wider ratio gears in them being that they are 4 speeds as opposed to 5 speeds? It seems in my mind they would have to be in order to cover the same speed range through gears.

If they are wider ratio, wouldn't the 4 speed bikes be better for off-road type of riding where the wide ratio off-road bikes like the Yamaha WR and Honda CRFX do well with their tranny?

[Chas_M]

If they are wider ratio, wouldn't the 4 speed bikes be better for off-road type of riding where the wide ratio off-road bikes like the Yamaha WR and Honda CRFX do well with their tranny?

I fail to see the logic here. For sure the 4 speed wouldn't have anywhere near the total ratio spread of a 5 speed WR or CRFX. The advantage of a wide ratio 5 or 6 speed is that it is very versatile covering a wide range of riding conditions. A 4 speed, even if it was wide ratio which I doubt, couldn't even begin to handle the same riding range as the wide ratio 5 or 6 speed bikes.

[zig06]

When Kawasaki added a 5th gear to the KXF-450 in 2007 they didn't mess with the first four gears, they only added a higher 5th gear. So it only added more top end speed. When Suzuki went to a 5 speed in 2008 they closed up everything but pretty much left 1st gear where it was. So there's a smaller speed gap between each gear and more top end speed with the RMZ 5 speed transmission.

With the RM-x450, Suzuki did lower 1st and 2nd gear and give it a faster 5th gear as compared to the RM-z450. And while there's a bunch of riders that love their 4 speeds in the woods, I have to believe that when things really open up having a 5th gear would be nice.

And for what it's worth, here's a speed chart for the 2007 450's

[07RMZ450RC4ME]

I would doubt I hit over 77 at the track. I have been pretty deep into 4th but never felt like I needed another gear. I could see where on long trails you could run it at lower RPM's however in 5th.

[souphmars]

90.... That is scary.

[legdiks]

MY FOUR SPEED FOR ME HAS BEEN JUST FINE HANGTOWN,E-STREET,

ARGYLE,THE FOREST I LIVE I NOR CAL AND RIDE EVERYWHERE MY 450 LIKES 3rd, AND 4th and pulls on most . if it revs out @ 77 im ok with that i dont need to be that fast before the next turn.

[snb73]

No. I have an 07RMZ450 and ride with a buddie who has an 05YZ450F. On the fire roads I am tapped out in forth and he continues to pull away and then shifts to 5th.

The 4 speed RMZ450 is designed for an MX/SX track. On average the speeds never exceed 60-65 mph.

[legdiks]

yeah i see your point my cousin has an 02 kx 250 and can hit a lot higher speeds in wide open terrain than i can , but in single track and mx / sx i does work well

you can also play around with front and rear sprockets for different riding situations

[NorCal]

I've tapped 5th at the Liliputian cross country at Hangtown. It was pretty scary. A 4 speed

would have been no bueno.

[alstar250]

No. I have an 07RMZ450 and ride with a buddie who has an 05YZ450F. On the fire roads I am tapped out in forth and he continues to pull away and then shifts to 5th.

The 4 speed RMZ450 is designed for an MX/SX track. On average the speeds never exceed 60-65 mph.

The only way he "pulls away and shifts into 5th" is if he swapped in some WR450 gears... Yamaha YZ450's didn't get the 5th cog until the Aluminum frame version in 2006