About to perform a fork oil change (not Dt125)

[Jens Eskildsen]

Its easier to uninstall the cap when the forks are still mounted. Make sure to loosen the pinchbolts in the upper tripleclamb first.

And yes, the 102 sounds like 102mm from the top of the compressed fork (without spring installed) to the oil.

[Calum]

Easiest way is to pour the oil into a measuring jug and see how much came out.

[Irongamer727]

@Calum though you never know if someone else has filled the wrong amount of oil previously.

[Calum]

@Irongamer727 Be alreet. I'm assuming you've been riding the bike and it's not been a problem

[Irongamer727]

@Calum yeah I guess. Probably going ride the bike pretty hard with stupid wheelies during the summer. Do you want just slightly more oil then? Or just the specified level?

[NINJA]

@Irongamer727 I would stick with the specified amount, if you want the forks to be a bit stiffer, then just use thicker oil like 15-20 grade.

[Calum]

@NINJA Did we discuss this on another thread??? And thicker oil doesn't affect stiffness. I distinctly remember @Jens-Eskildsen Saying something. Or someone like that.

I think, if you want stiffer suspension, then you need to change the springs.

[NINJA]

@Calum Probably we go around in circles a lot on this forum!!! :grinning_face_with_smiling_eyes: :smiling_face_with_open_mouth_closed_eyes: :smiling_face_with_open_mouth_cold_sweat: :face_with_tears_of_joy:

[Calum]

@NINJA I can't remember.

Genuinely, as bad as this might sound, sometimes I actually struggle to recognise dreams from real life.

I've sat there at times thinking of something as if it actually happened. Only to remember it was a dream. Mental mate.

[NINJA]

@Calum You gotta stay off them drugs dude, I keep telling ya that there no good for ya!!! :grinning_face_with_smiling_eyes: :smiling_face_with_open_mouth_closed_eyes: :smiling_face_with_open_mouth_cold_sweat: :face_with_tears_of_joy:

But back on topic; I believe that the thicker oil slows the compression down, as it is harder to compress through the valves? Which in turn makes the forks slightly stiffer? But I may be wrong? And you are correct - Ultimately stiffer or progressive springs are the sure way to stiffen or upgrade their damping qualities.

[Calum]

This site has some good advice
https://advrider.com/f/threads/fork-oil-weight-change-whats-it-do.997592/

@NINJA It looks like the general consensus is that you're changing the dampening and rebound rate, not the same as stiffness.

Resulting affects are, yes it'll be harder to compress, but the inverse is also true. It won't rebound as quick. Sounds a bit deadly if you ask me.

[Minia]

@Calum said in About to perform a fork oil change (not Dt125):

@NINJA Did we discuss this on another thread??? And thicker oil doesn't affect stiffness. I distinctly remember @Jens-Eskildsen Saying something. Or someone like that.

I think, if you want stiffer suspension, then you need to change the springs.

If you want stiffer suspension with DT forks, you've got 2 choices. The better one, is to change the springs. The cheaper and alternative method is to fill the forks up more. Thicker oil will only affect the damping rate, I.E it would slow down your rebound rate. Afterall you cannot pressurise a liquid. What allows the fork to travel and suspend movement is the air inside. Increase the quantity of oil, you reduce the amount of air and therefore require more energy to move the extra density of oil.

Now I've never taken the DT forks apart so I genuinely don't know how much room you have to play with. But I can say if you're trying to get your suspension right for your bodyweight and leg height, it is a lengthy and arduous process! Took me a few days to get right on the GasGas.

[NINJA]

@Calum I used to do it all the time on my mountain bikes Rock Shox, they did change as you have suggested tho. I never had any problems and the forks were much better after the thicker oil was added.

[theportingmaster]

486ml + or - 2.5ml so just under 1/2 a litre of oil.