Fork oil

[markusmaximus]

I've noticed recently that I get the occasional jarring when riding my 05 Nomad over road bumps, esp at intersections, despite how the rear shocks are set.

Was wondering how often front fork oil should be changed and how I will know when it should be changed. The service manual states only to inspect every 2 years for leaks.

I've owned the bike for 18 months and seriously doubt the oil was ever changed. Any help will be appreciated.

Thanks.

[cdneh]

The dealer told me he likes to change the fork oil at 10 000 km. He says that the quality of the fork oil from the factory is not that great. I had it done on my last bike and noticed some difference.

[dogdoc]

My '05 hits the bumps a little harder too Mark so its time i think.

[ringadingh]

They come with 10wt oil in them which gives a mushy ride, especially after a few seasons. I replaced mine with 15wt oil and still find it to soft, next time I'll use 20wt oil unless I install progressive springs which is most likely the best thing to do.

[markusmaximus]

Originally Posted by Ringadingh

They come with 10wt oil in them which gives a mushy ride, especially after a few seasons. I replaced mine with 15wt oil and still find it to soft, next time I'll use 20wt oil unless I install progressive springs which is most likely the best thing to do.

Pardon my ignorance, but would a "mushy" ride translate into this jarring that I feel? What is it about the oil that might cause my issues?

[ringadingh]

You have to determine if its the front forks bottoming out, or the rear shock or both, when you hit a bump.
If its the rear shocks you can set the springs at a higher setting, and add some air to them so the don't bottom out anymore. If this doesn't cure the problem then the shocks may be defective.
If its forks bottoming out, all you can do is replace the oil with a heavier weight, or replace the fork springs. The oil is what absorbs the springiness in the front end. If its low or to light a weight, the bike will bottom out on bumps and give you that sharp jarring that you feel.
The mushiness is usually the diving of the front end when you hit the front brakes fairly hard.

[markusmaximus]

Originally Posted by Ringadingh

You have to determine if its the front forks bottoming out, or the rear shock or both, when you hit a bump.
If its the rear shocks you can set the springs at a higher setting, and add some air to them so the don't bottom out anymore. If this doesn't cure the problem then the shocks may be defective.
If its forks bottoming out, all you can do is replace the oil with a heavier weight, or replace the fork springs. The oil is what absorbs the springiness in the front end. If its low or to light a weight, the bike will bottom out on bumps and give you that sharp jarring that you feel.
The mushiness is usually the diving of the front end when you hit the front brakes fairly hard.

Great explanation Ringadingh. That helps alot Thanks.

[Jared]

I replaced the oil on my 05 earlier this summer. Fairly easy job.

[ncnomader]

I recently bought an '08 with 12,000 miles and my bike does the same thing so I wonder if it's the nature of the bike. Of course others on here may not have the same issue?