BASIC BIKE SET UP

• Introductions       
• Testing and Adjusting      
• Setting Rider Sag
  

Before the first ride on a new or used bike, some time spent on basic bike set up will help to ensure the best results. New bike suspension, valving and spring rate are pre-selected by the manufacturer in order to give the widest variety of riders adequate performance under various conditions focusing on the bike’s intended use.

The first step we recommend is to set the rear suspension sag. Generally, the rear suspension sag should be 1/3 of the bike’s total rear wheel travel. For motocross bikes, 4” or 100mm; off-road bikes with slightly less total suspension travel such as KDX 200/220 or XR 250, should start with 90mm or 3-5/8”. Using a hammer and long punch or drift, follow these instructions to set your rear spring sag:

THIS IS A TWO PERSON OPERATION

Put the bike on a stand with both wheels off of the ground.

Measure R1 from the center of the rear axle to a fixed point on the back of the bike, such as a muffler bolt, fender bolt, or a specific point on the rear fender.

Mark the fixed point for future reference.

Take the bike off the stand and sit on it in your normal riding position. Keep your feet on the ground with just enough weight on your feet to balance the bike.

Have the other person measure R3 from the center of the axle to the previously marked fixed point.

Calculate rider sag by subtracting the smaller from the larger measurement. This is easier when measurements are taken in metric, since you don't have to deal with fractions.

Adjust as necessary to achieve the recommended rider sag.

Note: The rider sag recommended above should be used as a guide. A different sag level may be appropriate due to differing riding styles, ability levels and riding conditions.

Always consult your manual. The manufacturers do extensive testing, and while in the end their settings might not be perfect for your usage or riding ability, the information is still useful and valid.

Checking Clicker Settings

The next step is to check your clicker settings. Most manufacturer recommendations are achieved by starting with the clickers at full maximum (fully clockwise) and counting back to the recommended number or clicker setting. See if the manufacturer or your suspension tuner recommends 9 clicks out shock compression; turn the clicker all the way clockwise until it stops and turn it back counter clockwise 9 clicks. Check your manual and make sure the clickers match the manufacturer’s recommendation or in the case of a used bike that has already had suspension tuning by a professional, just check and note where the clickers are set. Some savvy riders like to note right on the shock and fork with an indelible marker the current clicker settings. These can easily be removed with contact cleaner.

Next check the torque spec for your front fork pinch bolts. Standard torque with 8mm pinch bolts should be 12-14 foot pounds. It is extremely important that the lower triple clamp pinch bolts not be over tightened when the bike is equipped with inverted forks, as it will cause binding and poor front fork performance. (Note: I had always torqued the pinch bolts on my 1997 YZ125 with a genuine torque wrench using the specs given in the owners manual. The forks were never very compliant on roots and rocks. One day I decided to try torqueing the bolts 2 ftlbs less than what the manual called for. They worked perfectly after that. Either my torque wrench needed recalibration or the conversion in the manual was incorrect. - Tim)

Take all possible care when riding a used bike to be sure the bearings in the linkage, swing arm, steering head and shock heim(s) are in good condition and well greased. A dry or worn out bearing will cause poor suspension action, making it impossible to properly evaluate your fork and shock set up.

Now gear up and take your first test ride. Use this time to let new suspension units break in at least one to three full hours. During this time, make some general observations about your suspension performance but avoid making harsh judgments at this point.

Suspension Testing and Adjustment:

The best way to evaluate and set up your front fork and rear shock is to set up a small test track which should include: small bumps, roots, rocks, turn entrance and exit chop, a “G” load which will use up most of your suspension travel with a steep exit lip (this will be helpful in determining rebound adjustment), small and large hoopdedos, dropoffs or jump landings (that you feel comfortable with per your riding level) and a log crossing (if appropriate). I recommend the test track be a maximum 2-1/2 miles long since you will use these obstacles as your control and should continually utilize the exact same bumps so that your observations about suspension adjustment and changes reflect the changes themselves, not random differences in bumps encountered on a trail ride or an event.

Now start to circulate the track making changes as needed. It’s okay to go back over and over again any obstacle where you feel there is need for improvement. However, keep in mind that the bike has to work everywhere. It must absorb the abrupt square edge rocks and steer precisely as well as offer adequate stability at higher speeds. So in the end, there may be a fair amount of compromise to achieve the best package of settings to serve you well in the real world! Remember to be realistic. You may be hitting the obstacles aggressively when you’re riding the small test track but sometimes a more plush, lighter setting will really pay in rocky and rooty conditions when riding a 2 or 3 hour hare scramble or any long day on your bike. I always tell riders that when doing suspension testing and set up, to “trust your own judgment.” Don’t be influenced by what other riders say or what you read in a magazine test article, the conditions and rider levels may not represent your personal use.

Oversteer – Understeer: How it relates to spring selection and suspension adjustment:

Oversteer is a term which describes too quick steering. Some symptoms of this would be lack of stability at higher speeds and a tendency for the front wheel to tuck under in loamy or sandy turns, a situation known as “high side.”

Understeer is a term which describes sluggish turning. Some symptoms would be difficulty to institute a turn or a tendency for the motorcycle to always feel it wants to go over the berm or stay to the outside of a corner.

Ideally, we want to achieve neutral turning and balanced suspension. Lets say your testing shows your bike has understeer. Some possible solutions for this would be:

A. Slide fork tubes up into the triple clamps thus shifting weight distribution onto the front wheel thereby reducing the rake angle and quickening steering.

B. Increase tension on rear shock spring thus shifting weight distribution onto the front wheel.

These are two simple changes that can dramatically alter the handling, steering and suspension performance of your motorcycle. Some clues that might help you to determine your best course of action are:

1. REAR SHOCK:

Compare the installed length of your shock spring with the free length of the shock spring (the shock spring will need to be removed for this). A general rule is that the installed shock spring should have a maximum of 20mm of tension (preload). Excessive preload will result in poor grip on small bumps like roots and rocks. Another way to determine proper spring selection is to put the bike on a stand, go through a similar measuring procedure as in setting the sag, but this time take the second measurement with no rider, only the bike’s weight. This measurement will determine “static sag.” While the correct static sag might vary depending on terrain, I suggest you should have a minimum of 1” static sag.

2. FRONT FORK:

Three ways you could alter steering by the front fork adjustment are:
A. Lower/higher oil level.
B. Reduce/increase preload on front fork springs.
C. Quicker/slower front fork clicker settings.

Any of these or a combination of same leaves you with good steering but excessive bottoming, you will have to keep trying other options until you get the desired result.

What to do if your still not happy:

So far we have covered some basic set up procedures and some possible adjustments that the average rider can do. But if you are still left scratching your head as to what to do, some indications that you need the help of a professional suspension tuner might be:

1. Your weight is quite a bit above average or below average (160-170 lbs). Unfortunately, if your weight falls 30-40 lbs above or below this level, you probably will maximize your results using a professional suspension tuner.

2. The riding conditions in your area are extreme. Either severe low speed and rocky terrain such as in New England or higher speed conditions such as the desert Southwest conditions.

3. Your bike was designed for use other than the use you intend it for. For example, a motocross bike converted for enduro/off-road or trail riding.

When selecting a suspension tuner make sure the tuner’s area of expertise suits your intended usage, talk to other riders and once you have narrowed it down, speak directly with some tuners you have chosen. Describe the type of obstacles you feel the need to overcome. Remember he is the expert. He may ask you questions that will help determine the best course of action. Be realistic when discussing your use and riding level. I think that communication is the most important component in your getting satisfaction from your suspension tuner. In my experience I have found that any suspension tuner that has lasted in this business is probably quite good and you should base a lot of your decision on the feeling that the tuner you spoke to understands your use, your riding level and has expertise tuning the particular bike you own.

After you have determined with your tuner what modifications are to be made, disassemble and pack up your front forks and rear shock. Enclose a detailed written note to your suspension tuner highlighting the particular concerns you have with your suspension as well as details of your telephone conversation such as procedures to be performed and parts you have agreed to change, your weight, your riding level, your daytime phone number and the address you want the parts shipped back to. Remember, your suspension tuner probably talks to many prospective customers every day, so don’t assume anything. Write it all down in your note.

Before you ship your parts make absolutely sure there are no worn or dry bearings in your swing arm, shock linkage or steering head. Your motorcycle will only work correctly if all these items are in good repair and able to work harmoniously with a properly tuned suspension. If you find any questionable parts, immediately order the parts. Your satisfaction will be far greater if you do the whole job right the first time.

Make sure you have a good shipping box and heavy sealing tape; I like the fiberglass strapping tape. You also might consider investing in an inexpensive gun case; they are foam-lined and can be used again and again. However, both UPS and FEDEX charge $5 additiontal handling for non-corrugated packages - each direction. Tag each suspension component with your name and address and phone number. That way in the unlikely case that your box fails, you still will be able to get your parts back.

Best of luck and happy trails……

Drew Smith