Whale oil

[gregg_floren]

I was following the advice in the last issue of the Resonator Revisited about making a dip stick to check the fork oil level on my Trail Whale. For the initial mark to be accurate, you need to drain the forks and fill them with the recommended amount of oil. I got that part.

But it did get me thinking about the right oil to use these days. The manual calls for 10 W / 30 motor oil, which is probably what I put in them the last time I changed the oil in 1980 or so. Would that still be a viable option, or would it be a lot better to use a modern fork oil? What makes "Fork Oil" different from other types of oil? And what weight fork oil would for be suitable for the Whale with a 185 lb rider. I realize it depends somewhat on personal taste, but it looks like I am not going to have time to dial things in. I am going to have to live with an educated guess.

I could guess myself, but it would be "uneducated". Educated/experienced help would be appreciated.

Gregg

[Zyx]

Fork oil is an hydraulic fluid, probably closer to ATF in build and function than motor oil. Motor oil is more prone to foaming but may be a better lubricant. I recently had my forks rebuilt, and 20w was recommended. I tried it for break in and after draining the first time. I find it is too heavy for me. The bike is around 200 pounds, and I am less than 150 fully geared. 10w works better for me. It will depend on lots of things from temperature to how aggressively you ride. I am not as aggressive as I once was, but may be as aggressive once as I ever was....

Technically springs carry the weight, not fork oil. Fork oil dampens the reaction to movement and heavier things move springs faster, so heavier oil compensates some for heavier riders. If you find yourself bottoming a lot, look for a heavier spring if there are any for Hodaka.

I would start with 20W fork oil and go from there. I would not use motor oil, and didn't use it even back in the 70's.

[Dale]

I use straight ATF in every motorcycle that I own. I have never had any reason to try anything else as it works well.

[Bullfrog]

I agree with the recommendation for 20 weight fork oil as a starting point.

Ed
PS: 20 weight is what I run in the model 03 forks on my "go fast" machine - essentially the same forks with different springs. Even with all the different factors like bike weight, rider aggressiveness, spring rate, etc. . . . 20 weight ought to be close.

[MTRob]

Don't listen to these old farts, they don't understand the great fork oil that's out there today. OH Crap what am I talking about I'am an old Fart
MTRob

[Zyx]

I use modern hi-performance fork fluid now, and used what passed for fork oil in the 70's, but now that it is mentioned, I have also used ATF in the past. Being a low foam hydraulic fluid, why not?

One note though. Don't assume that because the forks appear to be working that all is well. I stripped mine down a couple weeks ago, to do a thorough cleaning after breaking in new tubes. One of the two was galling badly on the outer leg inner wall due to a metal burr on the base of the new fork tube where the iron bushing is pinned to the tube. I had to deburr the inside of the outer leg (a pain to do) and dress down the leg end to remove extraneous metal at the pin. Good now, but if it had been left to go longer could have done serious damage to the outer leg. There was of course a lot of metal trash in the fluid.

Worth taking them apart and verifying condition. Any fluid from ATF on up should provide adequate lubrication, but nothing prevents damage from metal burrs on the moving parts. If you drain the forks and find metal debris, take them apart.