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Front End Fix & Emulators
2001/8/20 12:00
From Mount Airy
Posts: 456
Level : 19; EXP : 79
HP : 0 / 469
MP : 152 / 25578

Ben Wank
VBOOST Volume 1, Issue 4, 1997

Finally abandoned my lubber washer completely out of the steering assembly, which had the tendency to loosen every couple 100 miles -inviting headshake again. Installed a steel-tooth type lock washer with I" inner diameter, a steel washer to raise the fork tubes just a little bit, added the upper triple clamp and torqued everything down. Before I could adjust the ring nuts without any major effort. Now they do not move -and stay in place (even after a couple of hundred miles). THAT is fixed.
Compared to the smooth ST2 suspension I thought I could pay even a little more attention to Me Max suspension: used 1.5 turns of compression damper pre-load (emulator) versus the 2 turns default recommended by Race Tech. Oh happy day harshness was GONE (rider weight = 15O Ibs).
For anybody interested in suspension tuning, I copied the following at1iclc fro you freaks (skip here, Paul -it does not enhance straight line blasts). I think it's from "America" Road Racing", June
"The current crop of sport bikes have the most sophisticated and adjustable suspension systems ever offered to the general public. This suspension technology is as well and good if you understand how it works and how it's supposed to be setup, but like the surgeon's scalpel, you can do an awful lot of damage if you don't know what you’re doing when turning the damping dials or changing spring preload. Suspensions set up for any high performance sportbike begins with selling race-sag. Race sag is the amount the suspension compresses with the rider 01/ board. Before YOII can set the sag you must calculate what the correct race sag is for your bike. This is done by finding the total suspension travel (V-Max front = 140mt/l front, 85mm rear) and dividing by three (four for a race bike). (That's bet1veen 3Smm and 47mm for the Vmax forks, and between 21 mm and 28mm on the stock rear suspension.) The suspension travel for any bike can be found in the owner’s manual) Vmax manual page 8-12) Now get two friends and a metric tape measure. We are going to adjust the sag by varying the preload on the springs. If the bike sags more than the specified amount \1ihen you sit 011 it we will increase the preload by turning the preload collar clockwise.-counterclockwise if the bike doesn't sag enough. Put on ALL of your riding gear and seat yourself in the saddle while friend #I holds the front of the bike so you can get into your riding position. Remember, your feet have to be ON the pegs. Have friend #2 bounce the bike the suspension up and down a couple of times and then measure the a point on the rear fender and the rear axle(loaded and fully extended index points on the fork stanchions). Do not hold the brake or turn the front wheel while measuring the sag. Once the first measurement is taken put the bike on its center stand or on a crate so that the rear wheel is off the ground and re-measure the same two points. Subtract the first measurement from the second and the result is your sag.
Now would be a good time to check and see if the rear shock spring on your bike is the correct one for your weight. You can get the correct sag with almost all any spring by adjusting the preload, but measuring the unloaded or free sag will tell you if a different spring rate is called for. To do this simply hold the bike upright and re-measure the same two points used for checking the sag, except now only the bike's weight compresses the suspension. A good free sag number for a street bike is 10mm, but a race bike will work better if the unlade sag is 2mm to 5mm. If you find that your bike has more than 10mm of free sag, your spring is too stiff for your weight and a replacement is called for. The converse is also true. If the bike is topped out, meaning it has no free sag whatsoever, then your spring is too soft, this may sound backwards. but remember if you started with a spring that you knew was too soft you would have to add a lot of preload to get the race sag right, and when you got of the bike and measured the free sag all that preload would not allow the bike to settle much under its own weight.
Street bikes usually have soft springs and need too much preload. This gives a good freeway ride, but if you find that your bike constantly runs wide on the exit of turns you can bet that your spring is too soft. If you are too light for the spring then the bike will have a harsh ride and it will be difficult to control the spring with the rebound damping adjuster. Now that you have the sag right and you have the correct spring for your bike you can begin setting the ride height. The ride height controls the amount of nose down pitch the bike rides at. Until recently, it was difficult to set the ride height independent of the sag. Usually you had to compromise the sag to get the ride height you wanted, but on a GSX-R750 we can shim the top shock mount to make the effective length of the shock longer, thereby raising the rear end up and increasing the nose pitch. This has the effect of adding weight to the front wheels. By the same token, if you remove the shims from the shock mount I can lower the rear end and add weight to the rear end, pulling the nose of the bike up more."

Posted on: 2013/10/18 14:55
Be safe out there and enjoy the ride....

Mike Moore
VMOA Webmaster

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