Twin Chamber GasGas forks for 2010 300R!!!

[Keg]

Seeing as though GasGas didn't think of offering twin chamber forks, here is a conversion on my EC300R 09.

Rides a bit smoother and my laps times were down when tested on the usual loop so I even raced with them on the weekend and found them pretty damn good. The 0.44kg spring rates were a little soft for me but that is easy fixed too as I have new set of Showa forks with heavier springs coming soon for my 2010 300R!

 

[noobi]

whats involved in the conversion?
and what kind of dual chamber fork did you use?

 

[PEB]

My 07 came with beefy 50mm twin chamber Zokes with the fancy black dlc coating. What would be trick are the new 53mm zokes.

 

[Keg]

I used a CRF set of forks, brakes and wheel. The 47mm forks are 1mm smaller diameter than the 48mm sachs, so I had to sleeve them. I used the CRF 240mm disc, but might have to get and oversize (for Jap bikes) 260mm like a standard gasser.

 

[noobi]

so the stock gg clamps, but with a 1mm sleeve between the clamping surfaces, otherwise just straight off a crf X or R?

 

[Keg]

Yeah...pretty close. I used 20thou (1/2mm) aluminium shim material for the sleeves. The axle seems fairly tight on the right hand side so when my R forks turn up I might have to lathe a tinny amount off the r/h wheel spacer.

 

[GG27]

Keg, I am interested in updating my EC250 08 from a 45 Mazzorrchi to a 47mm SHOWA from a crf or rmz. Do yo think I can use the same triple clamps just machining them down by 2 mil? Thanks

 

[GG27]

Does anybody know the showa fork tube diameter at top and bottom triple clamp positions.

 

[moto9]

I got my 45 marz on my 08 300 to work better than the showa's on my 03 cr 250...when I say better I mean plusher and compliant as well.
But I only do singletrack, no MX/jumping or high speed desert.
Mabye with some more shim movement I think they may work well there too.

I did a Taco kit (smart performance) on a friends CR and after re-working the kit a few times (softer) we got the fork to work pretty good...riding both bikes back to back on the same stretch of trail we both though the marz felt just a tad plusher on the heavy rooted sections.

With the Marz, I went with the heavier spring and lighter compression valving concept as well as stiffen up the rebound side to compensate for the heavier spring.
I also lightened up the mid valve by adding more float and a softer check plate.
The trails here in Hawaii are not like anything have ever ridden before mostly due to the root shapes which are like a board standing on edge "square" running in all different directions, now immagine someone greasing them and then spraying them down with water...you get Hawaiian ice... So now let's add quick elevation changes,rocks,logs covered with a slimy moss, sorry I forgot the sudden down pours and flash flooding.
First few dozzen time I road these jungle trails I was picking up my bike more then I was riding it.
So, I guess my point is I am now very happy with the Marz and don't feel the need to change the fork.

 

[GG27]

Moto9,
My zorks are working perfectly in single track extreme rocky conditions here in Greece (after I revalved them at the gasgas representative). My main complaint is that they are not progressive at the end of the stroke causing the fork to bottom easily. That is why I would preffer a twin chamber set up. I will try raising the oil level to 90cm and see how it works on the weekend.

Thanks

 

[moto9]

Moto9,
My zorks are working perfectly in single track extreme rocky conditions here in Greece (after I revalved them at the gasgas representative). My main complaint is that they are not progressive at the end of the stroke causing the fork to bottom easily. That is why I would preffer a twin chamber set up. I will try raising the oil level to 90cm and see how it works on the weekend.

Thanks

What spring rate are you running, IMHO even if the spring rate is right for your weigh if your an aggressive rider you might benefit from a stiffer spring.

If raising the oil level doesn't work, you could try reducing the float height on the midvalve.

 

[nick790]

you could try reducing the float height on the midvalve.

How is this done and what effect does it have?

 

[moto9]

How is this done and what effect does it have?

The rod is removed from the cartridge.
On the end of the rod is a piston.
On the nut side of the piston is the rebound stack, the other side is the midvalve stack.
The midvalve stack is also spring loaded.
When the fork compresses oil is metered thru the midvalve, adjusting the stack configuration =(as in stiffness) distance it is allowed to float open, stiffness of the spring, piston port size all effect oil flow.
The midvalve sort of acts as a parashuite for the fork.
If more float is added the results are (in my best explaination) like using a smaller parashuite allowing the fork to compress quicker and deeper into the stroke.
Taking away float has an adverse affect.
Now I am no suspension Guru, I just know what I like and it took me a 3 times to get the forks where I like them..But I will say it was night and day difference.
I switched bikes with a friend that has a 09 EC300 (sachs fork, very simular design) and huge difference...same with the shock...I no longer complain about the hard seat...but I sure can feel it on his bike.

 

[GG27]

Moto9,

I have the standard .42 springs and I weigh 80 kgs. The suspension tuner put sae5 fork oil @ 110mm. Should I add about 20cc of sae10 to stiffen it up a bit?

I have it set up with 6 clicks Rebound out from fully in and 12 clicks Compression from fully in. Should I increase compression a bit?

Thanks

 

[nick790]

The rod is removed from the cartridge.
On the end of the rod is a piston.
On the nut side of the piston is the rebound stack, the other side is the midvalve stack.
The midvalve stack is also spring loaded.
When the fork compresses oil is metered thru the midvalve, adjusting the stack configuration =(as in stiffness) distance it is allowed to float open, stiffness of the spring, piston port size all effect oil flow.
The midvalve sort of acts as a parashuite for the fork.
If more float is added the results are (in my best explaination) like using a smaller parashuite allowing the fork to compress quicker and deeper into the stroke.
Taking away float has an adverse affect.
Now I am no suspension Guru, I just know what I like and it took me a 3 times to get the forks where I like them..But I will say it was night and day difference.
I switched bikes with a friend that has a 09 EC300 (sachs fork, very simular design) and huge difference...same with the shock...I no longer complain about the hard seat...but I sure can feel it on his bike.

Thanks, that explains things well. How did you add more float to yours?

 

[moto9]

Thanks, that explains things well. How did you add more float to yours?

There's a couple of ways...removing shims or replacing shims with thinner ones...decreasing the shim stack thickness. I did a combination of both.

 

[jiauka]

Does anybody know the showa fork tube diameter at top and bottom triple clamp positions.

47mm USD Showa from RM: 54.5mm upper, 58.5mm lower

I nhave them fitted on my GG

http://www.gasgasrider.org/forum/showthread.php?t=4023&highlight=showa

have fun,

j.

 

[GG27]

Jiauka, thanks for the incredible info on the showa forks. Won't drilling the tripple clamps weaken their strength?

Anyway I raised the oil level to 90mm and forks took the big hits and drop offs quite easily. Now I have my shock acting up after one hour of rough rocky single track, its jumping all over the place even if I just revalved it and serviced it 10 hours ago. During the first half hour it worked really good although I was bottom it afew times on the moto course. I'll call the gasgas agent and see what he has to say.

 

[GG27]

moto9

I think I have to jump the gun and get a pair of heavier springs since I still cannot get decent front end stability at high speed whoops and drop offs. What spring rate should I order, 45 or 48? I weigh 175lbs naked.

 

[moto9]

moto9

I think I have to jump the gun and get a pair of heavier springs since I still cannot get decent front end stability at high speed whoops and drop offs. What spring rate should I order, 45 or 48? I weigh 175lbs naked.

I have 45's, you might be better off to see if you can get a .46 from Race tech..
at 175 48's might be too much.
Consider this...you may still have handling and suspension issues if the bike is not ballanced out.
So, if you go heavier on the front but the rear spring is too soft you'll still have problems.
I read some posts about running I think it was 12mm of preload on the rear shock and ignore the sag numbers...that didn't work for me.
I went with a stiffer rear spring and set my free sag at 35mm which has me in the 4" rider sag +/- 1/4" and my bike feels just right, very ballanced.
Check your sag numbers and see where they are, but just for info, that sill may not mean much...when I raced MX I ran way stiffer springs for my weight...That's just the way I liked it.
Suspension comes down to personal prefrence.
I read an artical where a mx mag tested Ryan Huges bike and one of his teammates bikes...both the same bike but radically different suspension set-ups, one was very plush the other was super stiff...so go figure.
What every you do get the bike ballanced out
Sorry if this does'nt help you much.