Atomik 250 Fork Oil Qty

[Enrico21]

Howdy, I've searched the threads looking for info on the amount of fork oil in the Atomik Kuda Pro 250. Most of the threads say to measure it when it comes out and put the same back in. Unfortunatly mine has already come out before I had a chance to measure it (and run down my arm when I held up the fork to look at it) and I was wondering if anyone could tell me how many CC of fork oil to put intio each fork. Thanks in advance for letting me know.

 

[sean01]

start with 100 or 200 (doesnt really matter) in each leg and go from there, add more if too soft or remove if too stiff

 

[XLR8]

Howdy Enrico21,

I will state for the record, I am not in anyway a suspension expert !
I have just read a lot of info and used that info to get MY forks the way I like them!
I am happy to accept critisism if I have it at all wrong

I spoke to the guys at Atomik about a month back and they said between 150ml - 220ml max. They also said 175ml is the magic number I beg to differ unless you only weigh 50kgs.
I wanted to see how/why/what makes it all work, so with a bit of reading I found the simple basics of forks.

Oil - damping slows the travel of the suspension.
On the kuda pro forks this cannot be adjusted other than changing the weight of the oil. The clickers up top are for rebound rate only.

Spring rate - force required to compress the forks.
Kuda pro - Unless you can find a similar diameter spring, with a higher spring rate then the only adjustment would be a few shims.

Air - Creates a progressive spring.
Kuda pro - This is where you can make simple adjustments with the amount of fork oil, as the fork compresses the air inside the fork leg, the pressure increases exponentially (ok, big word) by lots. More oil- less space, air compresses quicker and vise versa. Jap bikes have an air bleed valve which is used to adjust this. The kuda pro doesn't. Anyone had any success in putting one in ?
But be aware as too much pressure will blow fork seals.

I have actually rebuilt my forks from the inside out (and they really aren't as crap as some make them out to be) and am currently running 300ml of 10wt.
The biggest issue I have found is the damping piston, both snapped off from the bottom of the shaft (inside the internal chamber). Once sorted they went back together and with a bit of testing, 300ml was where I got to.

I weigh 80kgs and the bike used to bottom out on practically every lump or bump,
Now the forks probably aren't as plush as my mates WR250 but are a much nicer ride than before. They rarely bottom out even over reasonable jumps.

Again I am no expert, but I thought I would share what I have learned.

Cheers all

 

[FMX_22]

wow lol .+reps mate

 

[terrapin_jk]

When you say you rebuilt them, which bits did you replace? And did you replace them with Atomik parts or get aftermarket parts?

 

[banga]

i dont mean to steal the thread but is there an after market forks you can buy around or replacement springs for them as i have the same prob on my 150cc TDR i know its a cheapy but any bump shes rough as guts

 

[logicquests]

Heaps of aftermarket forks available mate.

Really depends on your budget.

You can go for another pair of generic China forks. Some will be good and some will be bad. Once again the quality and quantity of oil used can make a huge difference.

You can take the next step up and get something with adjustable rebound and damping. These two features combined with the correct oil and quantity will give you the ability to tune your forks on the run making them perform as you need them to perform depending on your riding conditions and personal preference.

GPX Moto Minicross Black Label Fork Kit 730mm Complete Kit | Mini Bikes | Pitbikes | Dirt Bike Parts & Accessories | DHZ Mini Moto

FastAce Fork AS-03 [faas03] - $240.00 : Elstar Products, Factory-tuned Racing Motorbikes ATV (Quad Bikes), aftersale support, spare parts and accessories. An agent for Apollo motorbikes, Orion, Elstar Motorbikes Shineray. High-quality parts by FastAc

Just a couple of options for you. There are a myriad of options out there and the only real issue will be your budget.

Logic.

 

[banga]

thanks for the reply logic
well i went for the GPX Moto Minicross Black Label Fork Kit 730mm Complete Kit
hoping i get it by the weekend an go out an have a play

 

[XLR8]

Howdy Terrapin,

Rebuilt: I basically stripped them down (outer and inner chamber) be aware that the inner chamber tube is crimped onto the alloy fixtures, this pretty much destroys the tube when getting them apart.
I HAD to do this as both pistons inside had broken away from the flimsy alloy thread that holds them onto the inner shaft. I replaced the tubes with HYDRAULIC TUBE (nice straight tube with no seam inside) I then machined a hole into the inner bottom alloy fixture,( that holds the piston) replacing the alloy thread with a stainless steel bolt. I am pretty lucky as I have a lathe in the shed, and now a milling machine that is close to operational. This isn't needed if the forks are still fully operational. Just make sure you dont close the rebound valve off totally as I think this is what may have caused the damage in the first place.
I have a second set of forks which I am also going to modify, but this time I am aiming to thread the hydraulic tube and the alloy fixtures, so that everything comes apart easily without damage.
I haven't even looked for aftermarket springs, I just added 3, 2mm flat washers as shims, to the top of the spring. This did stiffen it up a little.
The forks are not even 6 months old and the fork seals weren't leaking, so I didn't see the need to replace those, I did replace the "O" rings though (which are cheap enough from CBC bearings).
There seemed to be a fair bit of crap inside the forks too, which with such tiny holes for the oil to pass through, any obstruction would cause issues. So a thorough cleaning was in order.
For those that don't have the time, tools or patience and just want something that works then yes, a new set of forks with rebound and damping adjustment would be the go. I tend to be on a budget and like to play with these things.
Fork oil at the very least will make a BIG difference to the forks, It will just be a bit of playing to get it how YOU like it.

Cheers

XLR8