Adjusting rear shock preload

[Hellgate]

When my suspension was totally stock, I set the shock at either 4 or 5. I weigh 175 w/o gear. It was better but when I had it up at 5, however the balance between the frontend and rearend seemed unbalanced to me. Once I installed my Race Tech springs if feel balanced and even between the two ends.

The stock shock is actually pretty good for general street riding. When pushed the damping is not quite there, but that will depand a lot on your weight.

Even if you don't want to do the RT springs a heavier oil will help a lot too. The stock oil is 5 or 7, I've seen both numbers, a 10, 12 or 15 will greatly improve the front to help balance out changes to the rear.

[Tripps]

Probably a stupid question, but does the centre-stand have to be down to adjust the preload?

TIA

[mstewar1]

I haven't had my coffee yet, so I may have to come back and edit this later...

As has been stated by others, determining the correct setting for the rear shock preload is found by measuring the sag of the bike.

I did a quick google search and the first hit was the site below. It's got a pretty good breakdown of suspension concepts and even some pictures. (But they don't seem to know how to spell "tire".) ;o)

Motorcycle Suspension Setup - motor-racing.co.uk

Unfortunately, they talk about adjustments that our stock suspension doesn't offer -- rebound on the shock, and any external adjustment on the fork.

I definitely wouldn't recommend using your rear shock absorber as a means to adjust ride height. The spring preload is there to get the damper set correctly for your weight. And when you're checking the sag to set the shock, you'll want to pay attention to what's going on with the fork. It should sag the correct amount as well. Balance is what we're after.

As Hellgate mentioned, there are different weight oils that can be used for the fork. Changing fork oil weight will change the amount that the fork sags but different weight oil will also cause the fork to behave differently. Examples include, too light an oil weight for a larger rider will cause the fork to just blow through its travel and possibly/likely bottom out. Too heavy and you may not get any responsiveness, any feedback from the front end.

Forgive me for the blah blah blah. Suspension is really not all that mysterious once you get a good understanding of the core concepts. Keep asking questions folks!

[mstewar1]

Sorry, meant to answer Tripps question, too. Not a dumb question at all.

It doesn't matter which stand the bike is on. Though bear in mind that when you turn the adjuster you're increasing/decreasing the amount of initial pressure placed upon the spring. I suppose it's possible that placing the bike on the center stand, thereby unweighting the damper, could make the turning of the adjuster a little easier. But I don't think it'll make a huge difference, unless yours is particularly old, grimy, or sticky.

[grumpy1luvs2eat]

I set mine on #1 for just riding around town and to work, but I change it days that I may getting into twisties. I weigh 155lbs. I change it to #3 or 4. GRUMPY

[grumpy1luvs2eat]

Originally Posted by Tripps

Probably a stupid question, but does the centre-stand have to be down to adjust the preload?

TIA

There are NO stupid questions when seeking knowledge, GRUMPY

[abacall]

I'm 150, and set on 4. I expreimented with all the settings and various tire pressures. I found that 4 keeps my front end from diving too much and the rear from feeling "skitty."
Don't forget to tweak your tire pressures when adjusting the suspension. With the stiffer shock, I had to dial down some tire pressure in order to reduce the tendency to slide.

[opds9091]

i am 170 with gear on and like to take the twisties and cut the corners. What would i use.

[mstewar1]

The best way to determine the correct setting is sag. Another, less precise way is to go ride a portion of your twisty road. Make a small adjustment. Lather, rinse, repeat. Small adjustments. Which on our stock bikes really only means turning the adjuster one click at a time in either direction.

Given your weight, I'm guessing you will fall, er sorry, be happy with it set on 3 or 4. So you might even run a stretch with it set on 2. I would imagine that the rear end will wallow and you'll feel as if the road is sorta sucking the power from your bike on 2. Try setting 5 and see if you can even feel your rear suspension moving. I'm guessing here, but it will probably lack feel. It may "feel" almost like it's rigid.

A bike is at its best when, during cornering, the suspension is extended not compressed. This is another reason to ride smooth, do your braking before the corner and be pouring the gas back on, smoothly, at the apex.

I'm not a big fan of attempting to change or adjust handling with tire pressure. I understand that a few pounds up or down may be a suitable call for addressing slight changes in ambient or road temps, but it's just not the same as setting the dampers correctly to begin with. And of course, you may want to change the fluid in your fork...but that's probably another thread.

My .02, change gladly given. Standard disclaimers apply, ymmv, void where prohibited...

[GAH]

I found the factory setting (3) to be to harsh. I set it at 1 and for me, 200lbs with no passengers, it made for a much more enjoyable ride, it seems to match the suppleness of the front forks better. I didn't notice any difference in ride height.