My hawk 250 build

[Ariel Red Hunter]

Originally Posted by pete

changing the oil won't make the forks stiffer... springs do that...
diffrent oil will just change the damping speed...
make spacers for the top of the springs or longer ones if it already
has them that will put more pre-load on the springs...
PVC water pipe works ok for spacers...

green.... yer got the kawasaki version....


...

Pete, Americans always describe hydraulic shocks, car, front forks, trucks, rear shocks as too hard or too soft. I think that's because for almost a century, the only way an owner over here could adjust ride and handling was by changing shocks, or by changing hydraulic oil in re-fillable shocks. When Progressive, or Works Performance starts winding variable rate front springs, that will make a bigger difference than just changing to a more or less viscous hydraulic oil. Dexron ATF really makes a difference in these forks. The oil that comes in them is little better than Kerosene.

[chuck]

Originally Posted by Sir kayakalot

Forgot to say that I also upgraded the spark plug. JerryHawk how do you like your gearing upgrade?

Great SHOT!!!!!!!

[chuck]

Great SHOT!!!!!

[pete]

[QUOTE=Ariel Red Hunter;240090]
Dexron ATF really makes a difference in these forks.
/QUOTE]

Why would yer ever use a ATF oil of a unknown CST rating
when theres so meany perpose made fork oils of diffrent
CST ratings to tune the fork action with...

kerosene... Yamaha's standard 00 fork oil "CST 2.5" used standard in most of there dirt
bikes is not much thicker than water


.

[Ariel Red Hunter]

[QUOTE=pete;240139]

Originally Posted by Ariel Red Hunter

Dexron ATF really makes a difference in these forks.
/QUOTE]

Why would yer ever use a ATF oil of a unknown CST rating
when theres so meany perpose made fork oils of diffrent
CST ratings to tune the fork action with...

kerosene... Yamaha's standard 00 fork oil "CST 2.5" used standard in most of there dirt
bikes is not much thicker than water


.

I doubt that Hawks have as sophisticated fork hydraulics as Yamaha's do. These Hawk forks work really well with GM's Dexron ATF oil. I don't know how it would work in any other fork. If you are telling me that the forks on a $5000.00 motorcycle are better made than ones for a $1200.00 motorcycle, I'm not surprised. You really think that General Motors doesn't know what the S.A.E. Rating of their ATF oil is? The stuff is made for very sophisticated automatic transmissions. The batch quality has to be held to very tight standards, or the warranty claims would be sky high. It is high quality, it is available, and it is cheap.

[pete]

[QUOTE=Ariel Red Hunter;240143]

Originally Posted by pete

I doubt that Hawks have as sophisticated fork hydraulics as Yamaha's do. These Hawk forks work really well with GM's Dexron ATF oil. I don't know how it would work in any other fork. If you are telling me that the forks on a $5000.00 motorcycle are better made than ones for a $1200.00 motorcycle, I'm not surprised. You really think that General Motors doesn't know what the S.A.E. Rating of their ATF oil is? The stuff is made for very sophisticated automatic transmissions. The batch quality has to be held to very tight standards, or the warranty claims would be sky high. It is high quality, it is available, and it is cheap.

now I understand....
If the forks are of a poor quility yer should use a oil never ment for the job..

SAE is a rating for lubication.... forks work by flow which is the centistroke rating "CST"




...

[Ariel Red Hunter]

[QUOTE=pete;240159]

Originally Posted by Ariel Red Hunter

now I understand....
If the forks are of a poor quility yer should use a oil never ment for the job..

SAE is a rating for lubication.... forks work by flow which is the centistroke rating "CST"




...

I'm glad that you understand. SAE is also a rating for viscosity, which also rates flow. The SAE lubrication specifics are the letters After the viscocity numbers. Viscosity controls flow rate. This may be true only in the United States, Mexico and Canada, as I don't know how many other countries use "Society of American Engineers" Saybolt testing of viscosity. I know England used to use a different metheod to do this, but I don't know if they still do.

[Sir kayakalot]

I don't have a problem with the spring right on my Hawk. I was just hoping to slow down the compression and rebound of the forks with a better quality oil.

[Sir kayakalot]

Meant "spring rate"

[Emerikol]

Personally, I find the rear spring/shock/suspension setup to be way to hard on my Hawk, and the front to be just about right. I may spend some time tweaking the front in the next couple of months, but I don't want to get too carried away trying to make the Hawk suspension as good as the DR's. That could get really expensive really quick. The only problem I really have is the rear. I'm honestly afraid that I'm going to fold the bike in half when I'm on my way down after a jump or hill and I'm airborne. It absorbs the initial shock of landing reasonably well, but there isn't any followthrough. It just seems to stop traveling. I've checked everything out and it isn't binding or locking up anywhere, and I've reviewed video of the jumps and everything seems to be moving well. I think it's just a hard setup. That's my two cents' worth, at least. I still really enjoy the bike, and I'm really looking forward to having it in Tampa next week.

[Ariel Red Hunter]

Originally Posted by Sir kayakalot

I don't have a problem with the spring right on my Hawk. I was just hoping to slow down the compression and rebound of the forks with a better quality oil.

Well, Dexron will do that. People have stated that Dexron "Transformed" the forks used on the Hawk. Drain the old fork oil into a measuring cup. Put the same amount or up to an ounce more of Dexron in each leg. There are other fork oils that will work, Bel-Ray is one, if you don't want to try Dexron.

[Ariel Red Hunter]

Originally Posted by Emerikol

Personally, I find the rear spring/shock/suspension setup to be way to hard on my Hawk, and the front to be just about right. I may spend some time tweaking the front in the next couple of months, but I don't want to get too carried away trying to make the Hawk suspension as good as the DR's. That could get really expensive really quick. The only problem I really have is the rear. I'm honestly afraid that I'm going to fold the bike in half when I'm on my way down after a jump or hill and I'm airborne. It absorbs the initial shock of landing reasonably well, but there isn't any followthrough. It just seems to stop traveling. I've checked everything out and it isn't binding or locking up anywhere, and I've reviewed video of the jumps and everything seems to be moving well. I think it's just a hard setup. That's my two cents' worth, at least. I still really enjoy the bike, and I'm really looking forward to having it in Tampa next week.

If it is too harsh in the rear, I'm guessing the spring rate is too high for your weight. I've forgotten where I found a piggyback resivoir shock for the back, but it was on Alibaba. Manufacturers have been known to put overly stout springs on vehicles with weak shocks. Harley Sportsters had this problem for many years at the rear.

[2LZ]

Originally Posted by Sir kayakalot

I don't have a problem with the spring right on my Hawk. I was just hoping to slow down the compression and rebound of the forks with a better quality oil.

Changing the fork fluid on these (any CB) will make a world of difference. Make sure you measure what you pour out of each. If it's a little spongy, add 10cc's... That way you won't go overboard if you feel you may need a little more later. Also measuring them will provide you that entertainment value of seeing if they filled them the same or not. ;-)

[OUTERLIMITS]

Originally Posted by Emerikol

Personally, I find the rear spring/shock/suspension setup to be way to hard on my Hawk, and the front to be just about right. I may spend some time tweaking the front in the next couple of months, but I don't want to get too carried away trying to make the Hawk suspension as good as the DR's. That could get really expensive really quick. The only problem I really have is the rear. I'm honestly afraid that I'm going to fold the bike in half when I'm on my way down after a jump or hill and I'm airborne. It absorbs the initial shock of landing reasonably well, but there isn't any followthrough. It just seems to stop traveling. I've checked everything out and it isn't binding or locking up anywhere, and I've reviewed video of the jumps and everything seems to be moving well. I think it's just a hard setup. That's my two cents' worth, at least. I still really enjoy the bike, and I'm really looking forward to having it in Tampa next week.

I saw a youtube video where a guy with a Hawk pointed out where there was tire contact under the rear fender/air box area. Have you noticed any contact there on your bike? Not sure I would be jumping these bikes for starters.

[wheelbender6]

"Ahhh Roger DeCoster one of my heroes for sure."
Me too. Last I heard, DeCoster is still managing professional motocross teams.
He still loves competition.