Racetech Emulators Adjustments

Yamaha Star V-Max VMAX Motorcycle Discussion Forum

Help Support VMAX Forum:

Gregoryuw

Well-Known Member
Joined
Oct 28, 2012
Messages
78
Reaction score
0
Location
Bucks County , Pa
Hey guys , has anyone done racetech emulators on there vmax in combination with progressive springs .
I have done my share of for forks , looks like standard drilling out the drill out damping rod and weld up the rebound holes .
Just wondering what spring on the emulator , blue or Yellow and how many turns on the adjuster you were running .
 

Glen007

Well-Known Member
Joined
Sep 29, 2011
Messages
55
Reaction score
0
Location
Seattle
Hmmm...I don't remember welding up the rebound holes. The emulators come with a decent set of instructions (though not great). It states the exact amount of damper holes to drill and where to drill them. I went with the stiffer of the springs (can't remember what color that was) and started with the recommended turn in. The fork will feel perfect in comparison to the stocks, but after awhile you may wish you had turned the screw a bit more. At least I do now. I've been too lazy to yank mine back out to get the extra turn I want on them, but will get around to it as it starts to warm up out.

FYI - I did Racetech springs with the gold emulator and it makes the front 100% better. It will feel like a different bike. The problem is, when you fix the front it instantly makes you feel how bad the back is. I'm actually planning on buying some Progressive 444's for the back tomorrow.
 

timscues

Well-Known Member
Supporting Member
Joined
Feb 23, 2011
Messages
370
Reaction score
2
Location
charlotte
I put them in recently and used the setup they came with I think it was the yellow spring, and the blue was for more like a competion set up, I had to enlarge the two holes and drill two extra, If I'm not mistaken drill to 5/16 and spaced out 10mm apart, could weld or braise up the small holes but I did not, I just got the bike on the road alittle stiff but I like it I went whith the 1kg springs and 15wt fork oil
 

davesax36

Well-Known Member
Joined
Nov 10, 2011
Messages
3,115
Reaction score
5
Location
Arlington, VA
So did anybody actually weld the rebound holes shut? The instructions talk about a set of kawasaki forks that need it done. That's not a step I want to get wrong.

Sent from my Galaxy Nexus using Tapatalk 2
 

m-cman

Alien Abductee
Joined
May 29, 2007
Messages
2,457
Reaction score
2
Location
Texas
I have the emulators and springs on my Max. My instructions had nothing about welding up holes, only drilling a little larger. Be sure you have the correct instructions for a Max. It was pretty easy to install. Remember to measure the preload spacer length from where the internal threads start, not the top of the fork tubes!!! About 1/2" to 3/4" inch difference if I remember correctly. If use the top of the fork tubes, the front will be very stiff! Too much preload.

Every bike may have different installation instructions.
 

ZackDaniels

Well-Known Member
Joined
Aug 21, 2012
Messages
637
Reaction score
0
Location
Chicago
Hey guys , has anyone done racetech emulators on there vmax in combination with progressive springs .
I have done my share of for forks , looks like standard drilling out the drill out damping rod and weld up the rebound holes .
Just wondering what spring on the emulator , blue or Yellow and how many turns on the adjuster you were running .
The emulator does the same job progressives do but better. It's designed for straight springs only and I wouldn't combine them with progressives at all.

Here's a detailed break down into the science of it:
http://www.racetech.com/page/title/Emulators-How They Work

Long story short(ish):
There's 2 jobs that suspension is there to do for you. One is the obvious shock absorbing. The second is the not as obvious rebound control.

A big fat ass spring can absorb impact just fine, but without something to control the rebound it's going to bounce just as hard as it was compressed on the way back out. Setting the spring inside a bunch of fork oil smooths out the violence of the rebound, but if it's sitting in oil to begin with it won't compress as fast as it needs to. The damping rod is there to let a bunch of oil splooge up and cover the spring on compression, but drain away on rebound. How much the oil works is controlled by the size of the holes in the bottom and top of the rod, and the viscosity of the oil.

The problem is that fluid dynamics is simple. Whatever amount of force is applied = the amount of oil covering your springs and controlling rebound. As such it will respond the same to a huge bump like crossing a railroad and something a little less violent like a speed bump. Progressive springs are designed to smooth that out. Requiring more force to fully compress due to the gradually tighter winding of the spring. Giving a small response to pebbles and road imperfections, but a massive response to railroad tracks.

Emulators perform the same job, but do so entirely differently (and more effectively). If you want to visualize how they work... figure a 2 liter of soda with the cap on but super loose. A small squeeze of the bottle isn't going to blow that cap off and won't allow the bottle to blow a bunch of soda all over the place, but a good firm squeeze and that cap is going to blow off with a bunch of high speed soda right behind it.

Emulators are the cap and your forks are the 2-liter, adjustable with 3 (?) settings to control how loose they sit on the top of the damping rod before completely blowing off. The analogy falls down a little because the emulator also has a hole in the top of it to allow some oil flow for the smaller bumps, but that's the general idea.

Progressives are designed to minimize the natural effect of rebound the spring is going to want to do, but emulators are designed to completely separate the 2 jobs your suspension needs to worry about. Emulators let the strength of the spring handle the absorbing and viscosity of the oil control the rebound. In traditional damping rod design both the spring and the oil have some unintended impact on both jobs. Progressive springs which are designed to do both jobs are wasted with an emulator setup. Combining them is using 2 different solutions to the same problem at the same time. The result is that neither solution works as well if at all.

:edit:
Have a picture
 
Top