|One of the biggest
misconceptions in the world of sportbikes about
suspension is that it only benefits those that are racing
or super aggressive etc. The truth is better suspension
helps the Novice rider with his/her first streetbike just
like it aids the Expert Racer at the top of the sport.
Doesn't matter if you are commuting in stop and go
traffic every day or trying to set a new lap record. If
the bike is more compliant, more comfortable and more
responsive then it is better for anyone's needs
regardless of skill level or intent of use. The
suspension can be further fine tuned to your specific
needs as the racer at the limit of traction aiming for a
new lap record has different needs from the damping rates
than the guy wanting to take his girlfriend on a ride to
his favorite lunch spot, but more compliance is always a
good thing whether you need a better ride on your daily
commute or more grip while getting on the gas exiting
What you are really purchasing when you buy aftermarket quality suspension is a greater margin of safety and a larger margin of error with some extra comfort thrown in. You get to ride faster with less drama and more compliance and feedback from your own motorcycle. For your specific needs of track riding there is no better way to improve the bike. When the bike is doing what it is supposed to underneath you then that frees up your mind to focus on other issues like body position, throttle management and hitting those brake markers with confidence instead of worrying about the ripples in the braking zone or that dip at the apex of Turn 6 and how they are going to upset the chassis etc. Proper suspension makes the bike predictable in all conditions. Additionally if the bike is working with you instead of fighting you into and out of every turn then when you do make a riding mistake you stand a much better chance of the bike correcting itself and keeping you on two wheels than if the bike is working against you and protesting your inputs the entire time.
The RC51 for its time has some well thought out OEM forks. A click here or there makes a difference in contrast to other period suspension parts like on my old 900RR where you could basically turn any adjuster you like from lock to lock without really affecting anything until you closed the entire circuit off However the springs rates are still designed around riding 2 up and the valving is completely out of spec for serious solo riding
Ultimately the bare minimum requirements for getting the RC51 to be compliant enough to keep you out of the ditch or gravel trap is a 20mm fork rework to revalve the forks to a more usable spec along with new fork springs, modifying the ridiculously long topout springs and slap an Ohlins Shock on the rear of the bike. You can go way further than that if your wallet allows, but those two items will give you both compliancy for traction keeping the tires in contact with the road and proper range of adjustment so that you can tune the geometry of the bike
Additonally depending on your needs you might find an aftermarket suspension linkage is beneficial as well
|I used to receive many e-mails inquiring about suspension set-up on the RC51 & at the time this website was started I was barely able to accurately convey just how much improvement quality aftermarket suspension made to the bike let alone be able to tune it. Funny enough now almost a decade later I am a test rider, track instructor and suspension technician and can pretty much work out any possible problem one might encounter with suspension or geometry set-ups, but prior to my very steep learning curve I started with the very basic knowledge listed below. As it seems that alot of people that simply do not know what the adjusters do or even where they are located. So I went looking for all the answers early on & I believe I found a pretty good article written by Dave Hodges. I did however take the liberty of altering the the sag numbers to suit the RC51 specifically|
With incorrect suspension setup, tire wear is increased and handling suffers, resulting in rider fatigue. Lap times can be dramatically slower and overall safety for both street and race enthusiasts is another issue. Add the frustration factor and it just makes sense to properly setup your suspension. The following guide will help you dial in your suspension for faster and safer riding both on and off the track.
Basic Setup: Check the following
Forks: 38-40mm of Rider Sag
Forks: Adjustment Locations
Rebound adjustment (if applicable) is
located near the top of the fork.
Forks: Lack of Rebound
: Forks are plush, but increasing speed
causes loss of control and traction.
Forks: Too Much Rebound
Forks: Lack of Compression
Forks: Too Much Compression
: Front end chatters or shakes entering turns. This is due to incorrect oil height and/or too much low speed compression damping
: Bumps and ripples are felt directly in the triple clamps and through the chassis. This causes the front wheel to bounce over bumps.
: Ride is generally hard, and gets even harder when braking or entering turns.
Solution:* Decrease compression "gradually" until control is regained.
Shocks: Adjustment Locations
Rebound adjustment (if applicable) is
located at the bottom of the shock.
Shock: Lack of Rebound
Shock: Too Much Rebound
Shock: Lack of Compression
Shock: Too Much Compression
Stock Tuning Limitations:
New motorcycles purchased from the dealership are generally set-up on the soft side, for a rider in the weight range of 140-165 lbs. If you are not in this range, you must retune the suspension for your weight within the internals of forks and shocks, the manufacturer puts valves with small venturis. This, along with shims, creates a damping curve. This works okay at slower speeds, but at higher speeds, when the suspension must react more quickly, the method cannot low enough oil, and you experience hydraulic lock. With hydraulic lock, there is no damping. The fork and/or shock cannot dampen correctly and handling suffers. The solution is to re-valve the active components for the proper damping curve. It does not matter what components you have, (Ohlins, Fox, KYB, Showa). If you can achieve the damping curve that is needed, it does not matter what brand name is on the component. Sometimes with stock components, when you turn the adjusters full in or out, you do not notice a difference. This is due to the fact that the manufacturer has put the damping curve in an area outside of your ideal range. After re-valving, the adjusters will be brought into play, and when you make an adjustment, you will be able to notice that they affect the way the way the fork or shock perform.
One of the problems with stock springs is, in most cases, it is of a progressive rate. This is to say, a spring at sag may be .85 kg per mm, and at 2.5 inches of travel, it may be 1.05 kg per mm, getting progressively stiffer. The ideal solution is to install a sprig with a straight rate, specific for your weight, and the weight of your motorcycle. In some cases, the factory installs a straight rate spring, but often the incorrect rate for your weight.
Remember to always make small adjustments, and keep notes! Sometimes more is not better and be patient. Suspension is an art/science.