Jockey Journal Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
20 Posts
Discussion Starter · #1 ·
How much fork oil is the proper amount for a set of 1949 Panhead forks? The the tubes are 4+ over, and the lowers are stock with stock springs. OEM HD.
 

·
Registered
Joined
·
8,510 Posts
If fresh its like 7 oz per. If just changing it, 6.5 if memory serves.
 

·
Registered
Joined
·
1,350 Posts
the inefficiency with the original fork assembly has lent it self to wanting regular 30W lawn mower engine oil - not what the MOCO has in the book been using that for as long as i can remember
 

·
Registered
Joined
·
3,990 Posts
+2 on the 30wt. works great. fyi, when a fork has longer tubes installed it doesn't change the amount of fork oil required. it still just needs enough to keep the damper covered.
 

·
Registered
Joined
·
734 Posts
I measure the height with the fork collapsed and springs removed. The captured air above the oil adds a little to bottoming resistance on the last third of the stroke. So if ya use 100MM/4 inches and it bottoms harsh add 5mm/1/4 inch at a time until it gently bottoms or stops under normal circumstances. If you go from a stock length fork to a +4" fork measure before swapping and use the same measurement-which requires more oil by volume for the longer tubes.

Oh and definitely use the 30 weight on the older forks. They need the viscosity.
 

·
Registered
Joined
·
8,510 Posts
Ok.....I'm not that familiar with hydraulic frontends. Springers mostly.

So 'splain why the 30wt. What is the difference between that and the OE fork oil? Seriously, I want to know.
 

·
Registered
Joined
·
734 Posts
The damping assembly for the 48-71 (oops 49-77) fork was designed prior to dedicated fork oil existed so works best with what it was designed for. Which is straight 30 wt motor oil.
 

·
Moderator
Joined
·
4,059 Posts
Thicker oil slows has a harder time moving through the damping orifice, leading to firmer front end feel.
 

·
Registered
Joined
·
1,350 Posts
i think it rides much smoother with the 30w than any fork oil - it becomes like a slow moving shock not like HD shocks that bounces
 
1 - 11 of 11 Posts
Top