Hi all, Decided to service the front forks on my 2006 Ultra Classic as I have a slight leak on one of the fork seals.

Got the lowers out and well you know how it goes. Take the Cowbells off and polish them. Might as well polish the lowers while we're at it. Oh, probably change the brake pads too.

Anyway, what I need to know is what you guys recommend for fork oil (weight etc.) and how much in each leg.

Cheers

DaveD

 

Last year I used the Harley oil. Thanking it's to thin, so have some Lucas 10wt synthetic waiting to go in soon. I'm thinking of putting in a extra ounce too.

 

See post #23.

https://www.hdforums.com/forum/touri...ml#post3734005

 

==========================

Just wondering which HD fork oil your ref too because HD offers mult visc so is it type maybe type E , SE HV DTY or SE Race you used?

I had 10wt fork oil (not HD fork oil) put in my 09 flhtcu last season that (had 9,700 miles on it at the time i bought it) in an attempt to firm them up a bit to reduce fork dive when braking & handling in general which didnt really help much at all.

Many guys say SE HVY DTY fork oil is the best for oil to run in stock HD forks firming them up a bit to reduce nose dive when braking & for best all around perf which i am going to be doing myself this time around in the next few wks using the Myte Vac method.

I just changed rear shock oil (Myte vac method worked great) to 10wt suspension oil thats specifically designed & formulated to better retain visc in rear shocks that heat the oil significantly more then from forks do which is why they mfg diff oils formulated with proper additive pkg for app being used in.

I didn't use fork oil in rear socks for a good reason because rear shocks (esp on lrg hvy baggers riding 2up & bags loaded) are stressed more then front forks are generating significantly more heat in rear shocks that reduces the visc of std fork oil because it's not properly formulated to not experience visc breakdown when heated to higher temp in a rear shock app on a hvy bike.

That results in a significant reduction is rear shock perf vs suspension oil thats properly formulated to tolerate additional heat generated in rear shocks therefor experiencing little to no visc loss when heated more in a rear shock app thus having little to no loss in overall rear sock perf as oil & shock temp increases.

But if changing the rear shock oil doesnt allow me to reduce air pressure enough to improve/reduce the harsh ride i am currently experiencing riding 2up with bags loaded currently requiring 50lbs (makes them very stiff ) to not bottom out sending back breaking shock thru the spine i will be going for Howard's Ohilins setup by the true master in the field to hopefully be done with that situation.

Scott

 

I used the E to get a base line of what it was saposed to be. I have pro action shocks no more harsh bottom out.

 

===============

Try HD's SE HVY DTY (Not SE Race) fork oil thats supposedly 15wt because it's widely viewed here in HdForums as the best all around performing oil in stock HD forks.

I plan to remove the 10wt thats currently in the front forks on my 09 flhtcu to HD's SE hvy dty said to be 15wt fork oil using the Myte (Mighty?) vac method saving time & effort.

I am doing that to firm up the forks a little more to improve handling a bit more along with reducing fork dive a bit more when braking too.

Scott

 

=============================

According to what i have read here in HdForums HD's Type E fork oil is supposedly to be approx 10wt.

But that has yet to be proven by actually having a new sample of HD's type " E " fork oil tested for viscosity by a certified test lab facility like for example the " Blackstone " test lab facility i used in the past for a motor oil testing project i was working on for Team Chevelle when they were experiencing a significant increase of flat tappet cam/lifter failures.

Scott

 

I put Harley SE (15 Wt, I think) in my 11 Road King and thought it was way too stiff. Ended up taking half of that out and adding E to replace what I took out and that was much better. With the 15 in there it just felt like it wasn't good for the bike with the jolts it was taking.

 

================

Well there are 2 SE fork oils,SE hvy dty -15w & SE Race 20wt so since your 100% sure which you used i'd not rec he try what you rec .

I say that because alot of guys here state they run the SE lighter hvy duty 15w in stock hd forks saying it forms them up a bit not harsh which i must read from a 100 dif guys posting that here over the past yr or so.

And out of all the positive results i read about using the se hvy dty (no se race) fork oil there was 1 feedback post i read where someone said it was a bit firm for them and may decide to mix some lighter E fork oil when they do the nex schd fork oil change not feeling as though it was harsh/bad enough to change the SE 15w fork oil before the next sch'd fork oil change .

So with that in mind i have a feeling your statement forks felt " Way Too Stiff " that more then likely used the heavier 20w SE Race fork oil & without you knowing for 100% sure which Se fork oil you in fact used unfortunately your experience just isnt accurate enough to be that usefull because it can be quite a diff in fork feel/perf between 15w and 20wt oil esp in cooler temp.

And again,thats keeping in mind the fact most guys that posted using lighter SE 15w oil had good things to say about it stating it wasnt overly harsh or hard,bit fimer yes but not overly harsh or hard.

When i was asking for fork oil rec @ my local HD dealer the srv'c rep & wrench both said when guys bring their HD's in for fork oil change & or maint if the owner says he's having issues fork dive when braking or with them being a bit too mushy/soft for crisp handling they automatically install SE hvy dty-15w fork oil and have no issues complaints after doing so.

Scott

 

7w bel-ray.... tried 20w, 15w and 10w, settled on 7w. This is on a '13 FLHTC. Best balance between firm and nice action.