Old shock new shock

[crmdgn]

I have tried here and online but found it difficult getting the 'how to' on my rear shock adjustment which is probably my ignorance in getting info. I saw lots of replacement info and how to fill the adjuster fluid back up but my question is this:

 

I weigh 220 - 225 and would like to adjust my rear shock most easily. Is sag important and if so how to do it with one person? Then I know about backing the adjuster out and back in about 3 clicks from the first bit of friction, but so what? What are the signs that it is right? And the damping?

 

Anyway, I just put a new tire on the rear and I want the shock to give me a supple ride and not affect tire wear.

 

I have the maintenance manual but could not find this info. And what would be the best way to tell if I need more fluid in the adjuster and what kind?

 

And don't be shy about telling me I am a dunce, lol.

 

Thanks

 

paul

2004 R1150RT with 18,900 miles on it.

[Paul De]

There are a bunch of things here and I'm sure you can get lots of input. Suspension adjustment can be quite specific to an individual rider and their style of riding beyond weight. Let’s start with some simple stuff and let others fill in

 

For the description you gave, you want a supple ride and not at the expense of tire wear. For now lets segregate out the tire wear because unless you really have the suspension out of whack (tires bouncing like a basket ball) tire wear will be more influenced by setting proper air pressure. There are a lot of threads here on that topic too

 

The perfection goal of a properly tuned suspension is to keep the wheel planted on the ground at all times while maintaining the chassis in a controlled way, meaning no big changes in pitch. Additionally because the motorcycle has a human at the controls the suspension should also allow adequate feed back of the road through the controls like handle bars and seat to allow appropriate decisions to be made about turning accelerating and breaking. Easily said and hard to get set right and harder still to get right for all road conditions, speed and riding style. That is why they make suspension adjustable in the first place. A smooth rider or stuff-it-in-turn-point and-shoot kind of rider will hsvevery different preferred settings. But in all cases the goal remains the same, wheels planted 100% of the time and the chassis under control (no extreme pitch changes).

 

For a stock suspension you have only the rear shock to adjust for spring preload and rebound damping. These two adjustments work hand in hand. This is a bit over simplified, but more spring preload requires more dampened to control bounce. Start by setting your spring preload. Don't worry about sag at this point as that is getting into a second level of adjusting which you can get to after you gain confidence with adjusting your suspension for spring preload and damping.

 

For the load you are carrying, adjust the spring preload to maintain the chassis in a fore to aft level position with the road and a neutral feel to the steering of the bike. Too many big pasta lunches, extra gear, a co-rider will require more spring.

 

Once that is achieved then because you want a plush ride you should turn the rebound damping down (toward the - sign) 1/4 turn at a time. If you go too far you will notice a tendency to bounce or pogo after going over a bump or better still a dip in the road. In the perfect case you will want the suspension to absorb the bump without any second or third bounce. Because you said plush and I am assuming you have a stock shock you may find to get the level of plush ride you may have to sacrifice a second bounce after a dip.....but don't back off the damping anymore than that or you will violate the goal of chassis control.

 

Try that and let us know how it worked out.

 

[crmdgn]

First off I am also a "Paul de" just little 'd', lol

 

Second I understand the theory, I think, just back the pre-load all the way off, maybe 3 - 4 clicks back on, go for a ride and evaluate the ride. Then add clicks or not depending on the ride.

 

I an assuming here it is fore and aft movement I am lookikng for?

 

When right, the dampening can be dealt with for the plushness (?)

 

If right, I'll work with that and then look at sag.

Thanks for the help.

 

 

paul de

[ShovelStrokeEd]

When you get past those basic adjustments, you are probably going to find that you really need a stiffer rear spring and quite possibly stiffer front as well. That will likely mean a new set of shocks as it takes special tooling to replace the spring on the stock shock absorber and it isn't all that high quality anyway.

 

Actually, the first adjustment that should be made is getting the spring rate correct for rider weight. While preload can, in a limited way, compensate somewhat for load, it is not a substitute for a spring of proper rate.

[Peter Parts]

Tires have a lot to do with plushness. Unfortunately, "vagueness of handling" seems to my butt to grow faster than "plush feel" as you decrease the air pressure. Consider a Bridgestone BT021 (replaced by BT023??).

 

My impression (at least on my machine) is that the front suspension has more to do with feel than the rear one.

 

Essentially you have no control. As far as I can tell from feel, the rebound adjuster isn't connected to anything inside or at least nothing that has much feel to it on a heavy touring machine on the street and without moving the control to either extreme setting. (Yes, I actually have taken apart my BMW shocks and have some understanding of these things.)

 

I sure wish people would stop calling the ride height adjuster a "pre-load" thing. It has no effect on spring rate or feel (short of bottoming out) and I think I will need to live to 100 years old before I stop hearing people say it does on this forum.

 

Stop fretting about sag. It isn't a suspension parameter that you feel except that it changes the handling geometry a little bit. You might notice that the steering is faster or slower or you may not.

 

This may sound very odd and ungracious, but the Munich design man weighs 35 lbs less than you but likes a stiff ride. At your weight, it might be that the ride feels a bit sporty compared to what you are used to but maybe you should consider again whether you might just like it after all. It is all about compromises.

 

I've done a lot of suspension re-design on BMWs over the years and I too wanted softer around town... but not too soft on the highway. As a 200 lb rider (with bags, Ventura rack, and 8 lb left-side balance weight), I made changes to my front strut (with very good outcome) and experimented with spring rate too. See URL below.

 

Ben

[NonComp]

My solution for single person sag adjustment is to get one of those ride-in front wheel chock/clamps that Harbour Freight sells. There is also a sag scale that you can buy, although I just use two yardsticks that are held together with a couple of zip ties.

[Jerry Duke]

I would suggest finding some experienced BMW riders that have adjusted their own bikes and have them look over your shoulder while you do it. You can get the setup all out of sort if you're not careful and could end up with a ride worse than what you have.