How does Showa's SFF work?

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phoenix91
Posts: 32
Joined: Tue Jul 17, 2012 12:10 am
Location: Hot Springs, Arkansas

How does Showa's SFF work?

Postby phoenix91 » Wed Dec 12, 2012 10:22 pm

I just recently started getting familiar with suspension functions in general. I can't exactly say I'm an expert but in my opinion, Showa's new SFF (separate function fork) is one of the sketchiest setups I've ever seen. Preload is adjustable on the left fork and NOT the right, rebound and damping is adjustable on the right and not the left. The left fork is air suspension, and the right is spring. This setup found it's way to mostly dirt bikes but most recently, the new 636. I have many questions about this trend but the biggest one is: HOW THE HELL DOES THIS WORK???

141_1010_04_o+2011_kawasaki_kx250f_first_test+sff_system.jpg


IMG_20121212_212100.jpg
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07 650r
Scorpion slip on
BMC air filter
short velocity stacks in airbox (thanks Gary!)
PCIII
SBL projectors with red halos and yellow eyes
Custom seat
Clip ons (over triple)
Lowered 1.5" in front
Integrated tail
Chopped screen
Red wheel tape
User avatar
phoenix91
Posts: 32
Joined: Tue Jul 17, 2012 12:10 am
Location: Hot Springs, Arkansas

Re: How does Showa's SFF work?

Postby phoenix91 » Thu Dec 13, 2012 4:04 pm

More specifically, how does is it practical when the forks are set up so differently? You would think that one fork would dive and behave differently than the other, causing the front wheel to constantly change pitch and angle. Also with one fork being air suspension, after a few miles, it would heat up causing the air to expand and having the same effect as jacking up the preload on one side mid-ride
07 650r
Scorpion slip on
BMC air filter
short velocity stacks in airbox (thanks Gary!)
PCIII
SBL projectors with red halos and yellow eyes
Custom seat
Clip ons (over triple)
Lowered 1.5" in front
Integrated tail
Chopped screen
Red wheel tape
User avatar
biketechted
Posts: 376
Joined: Sun Sep 06, 2009 8:22 pm

Re: How does Showa's SFF work?

Postby biketechted » Thu Dec 13, 2012 7:30 pm

I find your lack of faith disturbing.

http://www.motorcycle-usa.com/861/Motorcycle-Video/2011-Kawasaki-KX250F-Suspension-Tech-Video.aspx

I'd ride it to a goat fucking fo Showa.
If it can handle MX use, I'm pretty sure it can handle the road....and air springs have been used for a while now.
Regardless, you can thank the design of the USD fork combined with the oversized nature of the fork legs that lends itself to being structurally superior to traditional forks thus allowing one to develop new technologies heretofore and thusly.
User avatar
phoenix91
Posts: 32
Joined: Tue Jul 17, 2012 12:10 am
Location: Hot Springs, Arkansas

Re: How does Showa's SFF work?

Postby phoenix91 » Thu Dec 13, 2012 8:10 pm

I have complete faith in Kawasaki and Showa and I'm sure it works perfectly :thumbup: . I just was amazed that this bold design has developed to the point of being used in a super sport. I researched this design before it was used in the 636 and found it a little... wonky. The air suspension was known for losing quality during extended use due to the air expanding after heating up.
07 650r
Scorpion slip on
BMC air filter
short velocity stacks in airbox (thanks Gary!)
PCIII
SBL projectors with red halos and yellow eyes
Custom seat
Clip ons (over triple)
Lowered 1.5" in front
Integrated tail
Chopped screen
Red wheel tape
User avatar
biketechted
Posts: 376
Joined: Sun Sep 06, 2009 8:22 pm

Re: How does Showa's SFF work?

Postby biketechted » Fri Dec 14, 2012 9:30 pm

It looks like they have eliminated the friction aspect of the coil spring by using air. On that side at least, the heat may not be as high as it is on the coil side.
Also, with the coatings (Kashima, DLC, etc...) available, nowadays friction is reduced even further.
I believe that it uses a low pressure (30psi) air chamber which reduces internal pressure.

I'm a big fan of using air springs to help control damping, at least on mountain bikes and MX bikes.

Also, in general, the USD/Inverted fork design being used today is pretty rigid with the increase in fork tube diameter.

I only know enough about suspension to have a somewhat educatard conversation. Hopefully someone else can give a better technical description.
If not there are plenty of results via Google to keep you busy learning for a while.
What I do know is that most of the "against" comments I saw referenced air forks of old from the 80's and stuff.
Technology has a way of evolving in spite of what our limited minds may think can work or not...or does it? :what
User avatar
phoenix91
Posts: 32
Joined: Tue Jul 17, 2012 12:10 am
Location: Hot Springs, Arkansas

Re: How does Showa's SFF work?

Postby phoenix91 » Mon Jan 28, 2013 7:17 pm

Well, after being so skeptical of this setup, I've decided this will most likely be my next ride :)fu
Just need this new job to come through
07 650r
Scorpion slip on
BMC air filter
short velocity stacks in airbox (thanks Gary!)
PCIII
SBL projectors with red halos and yellow eyes
Custom seat
Clip ons (over triple)
Lowered 1.5" in front
Integrated tail
Chopped screen
Red wheel tape

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