Front fork settings

[SwampNut]

For fun along with education?

 

Because of this thread I was paying a lot more attention to my fork action the last few days.  I dialed in one more click of compression damping.  Setting long-travel forks is challenging to me, just so little experience with that.  I know they will have to squish more than street forks, but I'm trying to remove some of that.  The progressive nature of air is probably not the way to do it.

 

[superhawk996]

3 hours ago, tomek said:

So, are you done with your brotherly circle jerk yet? Yes? Good, let's bring closure to some of blithering nonsense suggested here.

 

So, let's say fork tops are airtight like tire, and would absolutely and positively never ever leak any air in or out. 

The sag on the front end on street bikes will be in 30-40 mm range. Let's say you are 20 mm off from recommended fluid level. Like 130 mm instead of 110 mm. 

 

This graph is from Ohlins cartridge kit for my R1, and illustrates relation between fork travel and oil level vs. air spring effect. It clearly illustrates in range of 30-40mm of fork travel (the sag) the difference in air spring would be less then 5 N for oil level being off by 20mm. 5 N = 0.5 kg.

 

Typical fork spring has a rate of 1.0kg/mm. So oil level being off by 20mm would change the sag by 0.5 mm. Totally irrelevant and not even possible to measure. Lol.

 

That was classic superhawk996 maneuver in the garage. Post something stupid, then run for help to his brother. Lol.

 

 

 

 

 

 

Classic Tom attack.  I stated early on that the effect would be minimal unless the oil level was extremely off.  Still waiting for your explanation on how air gets below the oil to get out of the seal.

[SwampNut]

I haven't expressed an opinion or picked a side, and even said so explicity, and he still thinks I'm arguing with him and agreeing with you.  Amazing.

 

Maybe I'm retarded (that was for Tomek) but it seems like adding REBOUND has made the fork less squishy under braking.  Maybe what I'm perceiving is a bounce?

 

[tomek]

1 hour ago, superhawk996 said:

Classic Tom attack.  I stated early on that the effect would be minimal unless the oil level was extremely off.  Still waiting for your explanation on how air gets below the oil to get out of the seal.

 

 

Also if you look again at that graph worse case scenario the difference would be around 15 N or 1.5mm that is still impossible to measure. Or nothing. You know the bell is ringing, etc. 

 

Another thing, the only time oil in fork is not mixed with air is when it has been sitting for a while. Other then that it is emulsion of oil and air, especially on the outside of cartridge.

That was primary reason for development of pressurized fork. No, not something like from 80's or swamps KTM. 

 

Good bye. 

[superhawk996]

I expected no answer, since there isn't one, but your doubling down on stupidity was pretty creative.

 

🤣

[tomek]

20 hours ago, SwampNut said:

I haven't expressed an opinion or picked a side, and even said so explicity, and he still thinks I'm arguing with him and agreeing with you.  Amazing.

 

Maybe I'm retarded (that was for Tomek) but it seems like adding REBOUND has made the fork less squishy under braking.  Maybe what I'm perceiving is a bounce?

 

I'd say something like 390 is sprung for metrosexual youth at around 120 pounds, because no adult should ride it, so getting more spring would be a good starting point.

 

 

[Tom]

Commented on some Dave Moss video with my fork issue, he just replied.

 

Spring out is standard procedure for air gap. I would use a 42 to 44cSt oil for those forks.

 

So...he would go thicker than OEM. 

[superhawk996]

17 minutes ago, FTM said:

Commented on some Dave Moss video with my fork issue, he just replied.

 

Spring out is standard procedure for air gap. I would use a 42 to 44cSt oil for those forks.

 

So...he would go thicker than OEM. 

Is this with the stock valving?  And is the oil recommendation based on rider weight or just an across the board recommendation for Birds?

[Tom]

My question to him was as follows;

 

I bought a 10N/mm (1kg/mm) linear springs for my CBR1100XX, weighing 100kg in gear, I'm wondering which oil should I use? The manual recommends Honda SS8 which is a 36 centistokes oil, should I stay within these specs or go lighter? Also, the fork spring manual advises 140mm air gap, Honda says 142, I presume both gaps would work but there's no mention is the air gap measured with or without springs inside?