Fork Oil - Harley Davidson Forums: Harley Davidson Motorcycle Forum
Harley-DavidsonForums.com is an independent enthusiast website owned and operated by VerticalScope Inc. Harley-DavidsonForums.com is not sponsored by or in any way affiliated with Harley-Davidson Inc.. The Harley Davidson names and logos are trademarks owned by Harley-Davidson Inc.

Go Back   Harley Davidson Forums: Harley Davidson Motorcycle Forum > Technical > Suspension

» Insurance
» Our Partners
»ATV Reviews
»Motorcycle Games
Reply
 
LinkBack Thread Tools Display Modes
Old 04-21-2010, 02:54 PM   #1 (permalink)
Grandstanding Member
 
Dave63's Avatar
 
Join Date: Jun 2008
Location: PA
Posts: 28,922
Fork Oil

Fork oils are as follows:

Harley Type E is 5 wt
Harley Type B is 10 wt
Screaming Eagle is 15 wt
Screaming Eagle Heavy (racing) is 20 wt

By adding the spacers in the fork tubes, you increased preload, causing less dive.

Adding thicker oil slows compression damping, however, if it gets cold in your area, 20wt can be a little too heavy and start making a "knocking" noise in the front, on fast movement, or while going over bumps. As can 15wt....

Your results will vary.
__________________
__________________________________________
“Peter, arson is a serious crime. It's not like smuggling Oriental hookers into the country, in steel drums........” ~ Glenn Quagmire~
Dave63 is offline   Reply With Quote
Old 02-21-2014, 08:13 AM   #2 (permalink)
Luke 22:36
 
Kainam's Avatar
 
Join Date: Oct 2006
Location: Kansas City
Posts: 15,140
Images: 149
Garage
Mobil 1 Dexron ATF is equivalent to a 7.5w fork oil.

Shovelhead service manuals used to call for ATF in the forks.
__________________
'05 Carbed Night Train
111 rwhp, 112 rwtq
Best 1/4 ET 12.557s
Best 1/4 MPH 108.59
Kainam is online now   Reply With Quote
Old 02-21-2014, 10:51 AM   #3 (permalink)
Addicted Since 2010
 
XL1200R's Avatar
 
Join Date: Jul 2011
Location: Upstate NY
Posts: 7,392
Images: 38
Garage
Quote:
Originally Posted by Kainam View Post
Mobil 1 Dexron ATF is equivalent to a 7.5w fork oil.

Shovelhead service manuals used to call for ATF in the forks.
Is it safe to run ATF in modern forks???
__________________
Link to my Youtube channel. All riding videos. Enjoy.
http://www.youtube.com/user/PittSteelers1345

"Mr. Lahey is this you talking or the liquor?"

"Randy...(takes a swig)...I am the Liquor!!!"
XL1200R is offline   Reply With Quote
Old 02-21-2014, 10:59 AM   #4 (permalink)
Grandstanding Member
 
Dave63's Avatar
 
Join Date: Jun 2008
Location: PA
Posts: 28,922
Quote:
Originally Posted by XL1200R View Post
Is it safe to run ATF in modern forks???
Yes. Its light hydraulic oil. The red is so you know what it is.

In the 70s.....Suzuki used brake fluid as a replacement oil.

Sent from Motorcycle.com App
__________________
__________________________________________
“Peter, arson is a serious crime. It's not like smuggling Oriental hookers into the country, in steel drums........” ~ Glenn Quagmire~
Dave63 is offline   Reply With Quote
Old 02-21-2014, 11:08 AM   #5 (permalink)
Addicted Since 2010
 
XL1200R's Avatar
 
Join Date: Jul 2011
Location: Upstate NY
Posts: 7,392
Images: 38
Garage
Quote:
Originally Posted by Dave63 View Post
Yes. Its light hydraulic oil. The red is so you know what it is.

In the 70s.....Suzuki used brake fluid as a replacement oil.

Sent from Motorcycle.com App
I may use that when I put my new springs in...I kinda don't want 10 that is in there now nor do I want the stock 5wt...
__________________
Link to my Youtube channel. All riding videos. Enjoy.
http://www.youtube.com/user/PittSteelers1345

"Mr. Lahey is this you talking or the liquor?"

"Randy...(takes a swig)...I am the Liquor!!!"
XL1200R is offline   Reply With Quote
Old 02-21-2014, 11:15 AM   #6 (permalink)
Grandstanding Member
 
Dave63's Avatar
 
Join Date: Jun 2008
Location: PA
Posts: 28,922
Quote:
Originally Posted by XL1200R View Post
I may use that when I put my new springs in...I kinda don't want 10 that is in there now nor do I want the stock 5wt...
My advice is just avoid type-F as it lacks lubrication qualities over other atf types. I've never used it myself and although fork oil is overpriced for what it is, I'd rather hear from someone that has firsthand knowledge using it.......

Sent from Motorcycle.com App
__________________
__________________________________________
“Peter, arson is a serious crime. It's not like smuggling Oriental hookers into the country, in steel drums........” ~ Glenn Quagmire~
Dave63 is offline   Reply With Quote
Old 02-21-2014, 11:17 AM   #7 (permalink)
Luke 22:36
 
Kainam's Avatar
 
Join Date: Oct 2006
Location: Kansas City
Posts: 15,140
Images: 149
Garage
Quote:
Originally Posted by XL1200R View Post
Is it safe to run ATF in modern forks???
HD Front telescopic suspension design hasn't change since ...... well, ever.
So yep, still safe to use in current front forks.


I'm getting ready to head over to a friends house to change up my front suspension.
FLST upper tubes (1.5" shorter than stock),
Progressive Monotube internals (lowered 2", for a total of -3.5" from stock).
I'll be using ATF for the fluid on reassembly.


Dave is right on not using Type-F, use Dexron.
__________________
'05 Carbed Night Train
111 rwhp, 112 rwtq
Best 1/4 ET 12.557s
Best 1/4 MPH 108.59
Kainam is online now   Reply With Quote
Old 02-21-2014, 11:28 AM   #8 (permalink)
Addicted Since 2010
 
XL1200R's Avatar
 
Join Date: Jul 2011
Location: Upstate NY
Posts: 7,392
Images: 38
Garage
Quote:
Originally Posted by Kainam View Post
HD Front telescopic suspension design hasn't change since ...... well, ever.
So yep, still safe to use in current front forks.


I'm getting ready to head over to a friends house to change up my front suspension.
FLST upper tubes (1.5" shorter than stock),
Progressive Monotube internals (lowered 2", for a total of -3.5" from stock).
I'll be using ATF for the fluid on reassembly.


Dave is right on not using Type-F, use Dexron.
I should have figured that lol.

Just wasn't sure in regards to seals and stuff..
__________________
Link to my Youtube channel. All riding videos. Enjoy.
http://www.youtube.com/user/PittSteelers1345

"Mr. Lahey is this you talking or the liquor?"

"Randy...(takes a swig)...I am the Liquor!!!"
XL1200R is offline   Reply With Quote
Old 02-21-2014, 11:53 AM   #9 (permalink)
Grandstanding Member
 
Dave63's Avatar
 
Join Date: Jun 2008
Location: PA
Posts: 28,922
Quote:
Originally Posted by XL1200R View Post
I should have figured that lol.

Just wasn't sure in regards to seals and stuff..
ATF is seal friendly. No issues there. Very benign fluid.

Sent from Motorcycle.com App
__________________
__________________________________________
“Peter, arson is a serious crime. It's not like smuggling Oriental hookers into the country, in steel drums........” ~ Glenn Quagmire~
Dave63 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -5. The time now is 11:27 PM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
This site is in no way affiliated with Harley-Davidson
Motorcycle News, Videos and Reviews
Honda Grom Forum Harley Davidson Forum Honda 600RR Kawasaki Forum Yamaha R6 Forum Yamaha FZ-09 Forum
1199 Panigale Forum Roadglide Forum Honda CBR1000 Forum Vulcan Forum Yamaha R1 Forum Yamaha R3 Forum
Ducati Monster Forum Harley Forums Honda CBR250R Forum ZX10R Forum Star Raider Forum Yamaha Viking Forum
Suzuki GSXR Forum V-Rod Forums Honda Shadow Forum Kawasaki Motorcycle Forum Star Warrior Forum KTM Duke 390 Forum
SV650 Forum BMW S1000RR Forum Honda Fury Forum Kawasaki Versys Forum Drag Racing Forum Ducati 899 Panigale Forum
Suzuki V-Strom BMW K1600 Triumph Forum Victory Forums Sportbikes BMW NineT Forum
Volusia Forum BMW F800 Forum Triumph 675 Forum MV Agusta Forum HD Street Forum Suzuki GW250 Forum
Yamaha Motorcycles Victory Gunner Forum Honda Vultus Forum HD LiveWire Forum