"Bumpy" front forks ?!?!?

[mkaczmarek]

I adjusted the air pressure in the front forks on my 1979 GS1000E the other day (as the pressure was too low), I set it to 13psi per side. I have the Suzuki Fork Air Pressure Gauge which gives me accurate readings and the suspension does seem stiffer now, not too much but noticeable. When I went for a ride I noticed that as I increased my cruising speed past about 45km/h (30mph) the front seemed to have a noticeable bumpiness to it. It was a weird feeling. I was wondering if anyone here ever encountered this with their bikes and what could be the culprit?

[KGB]

I usually run 0 (zero) air in my forks.
I run 20 weight oil in the forks.

Now some folks here run air in their forks and lighter or heavier weight oils.
We each have our own preferance.

So since adding air, and a good amount the front end feels "bumpy" ?
Like it's bouncing? Or riding over ripples?

Notice any oil leaking around the fork seals?
How much air is in the front tire?
A small alteration or change in one area can make changes in other areas.

[Billy Ricks]

I think you're just feeling the effects of the stiffened up suspension. Instead of soaking up the road you are now feeling it through the front end.

[AOD]

I never messed with my air setup, but 13 PSI sounds high. It may be TOO harsh, which makes it bumpy.

You should consider upgrading the springs and fork oil and reduce the dependance of the air system.

~Adam

[mkaczmarek]

The Owners Manual (and I think Service Manual) state that Factory settings are 11psi, and they mention that this is almost always "...too soft..." for so I figured 13psi wouldn't be a huge jump. The only thing they mentioned is not to exceed 35psi. I found this to be the easiest and fastest way to stiffen the front suspension a bit which is why I went this route. Although I haven't done any replacing of the oil at all since I got the bike. In terms of leakage, I didn't see anything obvious, but now that you mention it I will take a closer look. Is it OK to run the forks with 0psi ? I didn't realize that, I figured both systems were needed, but I guess my "guessing" was wrong, then again I'm very new to bikes and still learning all this.

Is there an easy way to check/top up, or replace the oil in the forks? or is disassembly always required with a complete replacement of fork oil in the exact amount?

[kalessin]

In order to check the fork oil level, you have to remove the forks from the bike, take the fork caps off and remove the springs to measure the level down from the top of the fully-compressed tube. If you've gone that far, you may as well also replace the fork oil, and fork seals if they haven't been replaced recently...

[fastpakr]

In order to check the fork oil level, you have to remove the forks from the bike, take the fork caps off and remove the springs to measure the level down from the top of the fully-compressed tube. If you've gone that far, you may as well also replace the fork oil, and fork seals if they haven't been replaced recently...

Maybe the first time, but once you've measured it and gotten it filled appropriately, you can just reassemble and mark a makeshift dipstick with the appropriate depth so you can check with the system assembled in the future. Just be sure to only check one at a time. Alternately, you can just drain them one at a time with the system assembled and flush them with kerosene, then refill with the proper amount. Close the fork back up, then switch to the other side.