Air adjustment

[allwx]

Lately, I've been re-learning how important it is to keep the rider's weight properly distributed in turns. I had developed a bad habit of actually leaning (slightly) my body AWAY from the turn. That is, if turning right in a high speed sweeper, shifting my body weight slightly to the left, and actually fighting the bike in the turn. This would contribute to instability, often oscillations.

 

So, even if everything on the bike is set up correctly, the rider's weight-shifting can nullify all of it. The bike might tend to fish around in turns. A rider might think there's something wrong with the bike, whereas the problem lies with riding technique.

 

I believe the correct method is, in an agressive turn, shift the butt weight in the same direction of the turn. If turning right, I shift my body weight onto my right buttock. This doesn't produce enough body movement to be discernable to others. It is a slight but deliberate shifting of weight. If I do this, then the bike settles down into the turn without any oscillation at all. The harder the turn, the more weight shift. In a hard turn with bike parts scraping, the rider's body might actually be leaning well off the bike. In the same direction of the turn. Like you see on race tracks. I don't understand the physics of this, but I think it has to do with lowering center of gravity.

[Grisolm1]

Harley dealers carry the progressive pump in the previous link. Get one and you can experiment on the road to find settings you like. I run 7 front and 40 rear.

 

This is the best compromise for me. My wife says this is the smoothest riding vehicle we own and when riding solo its just firm enough for my tastes so no need to adjust unless we are heavily loaded with luggage.

[darthandy]

Lately, I've been re-learning how important it is to keep the rider's weight properly distributed in turns. I had developed a bad habit of actually leaning (slightly) my body AWAY from the turn. That is, if turning right in a high speed sweeper, shifting my body weight slightly to the left, and actually fighting the bike in the turn. This would contribute to instability, often oscillations.

 

So, even if everything on the bike is set up correctly, the rider's weight-shifting can nullify all of it. The bike might tend to fish around in turns. A rider might think there's something wrong with the bike, whereas the problem lies with riding technique.

 

I believe the correct method is, in an agressive turn, shift the butt weight in the same direction of the turn. If turning right, I shift my body weight onto my right buttock. This doesn't produce enough body movement to be discernable to others. It is a slight but deliberate shifting of weight. If I do this, then the bike settles down into the turn without any oscillation at all. The harder the turn, the more weight shift. In a hard turn with bike parts scraping, the rider's body might actually be leaning well off the bike. In the same direction of the turn. Like you see on race tracks. I don't understand the physics of this, but I think it has to do with lowering center of gravity.

 

As a matter of fact, shifting body weight to one side as you describe, will help to lower the C. of G. a bit and could make a bit of a difference a far as stabilizing the bike through a turn. A better way to accomplish this, although it's a bit more difficult on a bike like the RSV, is to shift your weight onto the foot (And therefore the peg or board) that's on the inside of the turn. This will also help to move the C. of G. a bit lower. This helps to stabilize the bike and, in theory, it should help it to resist a slide to the outside of a turn by moving some weight closer to the outside edge of a tire which should, again in theory, keep it from "rolling away" from the turn, decreasing the amount of rubber on the road and therefore reducing traction. Virtually all road racers nowadays "hang off" their bikes to move the C. of G. as low as and towards the inside of the turn as they can. There have been arguments in recent years that, given today's high performance bikes with super ground clearance, enormous lean angles and super sticky tires, hanging off isn't really necessary...but no one wants to risk trying that as it might instead slow them down.

 

To a certain extent it could be useful on a street bike, but it is highly unlikely that you would be riding it hard enough on the street to really need to that. But avoiding a lean to the opposite side in a turn will definitely improve the manner in which you go through that turn.

 

Andy

[allwx]

I think I must've gotten into a bad habit of countersteering and then just lazily allowing my body to follow the bike into the turn. I went for a 100 miler today, into the mountains, and had a lot of time to think about this, and to practice.

 

I countersteer to initiate the turn, and simultaneously lean a bit forward, and shift my weight onto the buttcheek on the side of the turn. (this sounds a lot like what you said about foot pressure on the footboard). Keep a firm hand on the bars. the bike settles down into it and doesn't feel a bit wallowy, and it doesn't even feel like much of a lean is going on. Very solid feel.

 

Seems to me (again, I don't know no physics!) that if a bike the enormous likes of a Venture can be tamed by a firm hand and butt, then complaints about wallowing machines are less likely result of bad equipment, like shocks and tires, and more likely the result of not keeping the bike on a leash. I've had to learn and re-learn this lesson several times over the years. This is why I should take refresher training now and again.

[darthandy]

Yep...you've just discovered one of the little known problems regarding motorcycle handling. It even appears in one of the signatures for one of our members (But I don't remember who!). Namely...the occasional loose nut connecting the seat to the handlebars :rotf:

Once that nut gets fixed, the handling tends to improve noticeably!

 

And taking some kind of refresher course is not all that bad an idea. A lot of us tend to fall into bad habits without realizing it and then wonder what's wrong with the bike.

 

Andy

[BradT]

For those curves that have some dips or bumps, pay attention to how the back of the bike feels - does it wag, wallow or seem to have some frame flex? That is often worn out shocks, old fork oil, weak springs, not enough pre-load. And for reasons I do not yet fully understand, an OVER inflated rear tire on the RSV will greatly exacerbate any tendency to wag the rear when the bike is heavily loaded.

 

Goose, both my 99 and 08 felt like the rear wants to sway similar to above never felt right, but could never find the reason.

 

On my 08 I doubt the shocks are worn and fork oil may need changing. Do you think I could assume that the springs are not weak and the pre load would have been correct from the factory.

 

Not sure I understand the pre load on the forks ?

 

Brad

[myminpins]

UPDATE:

 

Well, got my pump today!! Works great!!

 

Found out it was at 15 psi in the rear - I put it up to 30 psi.

 

Found out it was ZERO in the front forks - I put it up to 5 psi each.

 

Can't wait for Mike to get up (he works nights) so we can go test it out and see how it feels. It should be much easier for Mike to handle since it was on ZERO in the front. I just hope it's not too rough for me so we'll see. Will let you guys know!!!!

[V7Goose]

Goose, both my 99 and 08 felt like the rear wants to sway similar to above never felt right, but could never find the reason.

 

On my 08 I doubt the shocks are worn and fork oil may need changing. Do you think I could assume that the springs are not weak and the pre load would have been correct from the factory.

 

Not sure I understand the pre load on the forks ?

 

Brad

Suspension preload on the Royal Stars is controlled by how much air is in the shock or forks - the air pressure works like an additional or stiffer spring. Suspension rebound is controlled by the thickness/condition of the oil and internal valving. Rebound is generally not adjustable unless you can change the oil (such as the front forks).

 

An overly simplistic explanation is simply that the strength of the spring (and internal valving/oil weight) controls how fast the wheel moves UP when it hits a bump (and how far it moves up, based on the size of the bump and how fast it was hit), and rebound is the act of the spring pushing the wheel back. Damping controls how fast the wheel travels back down. Proper damping allows the suspension to quickly return to its previous position without overshooting or bouncing.

 

Since the handling of a bike is greatly affected by how much travel there is in the suspension and the exact angle of the front suspension in relation to the road, the preload adjustment basically allows the bike to settle to the same exact height and angle for different weights. Where the shock has a moveable shoulder, this is accomplished by simply moving the spring further away from one end of the shock, in effect making the shock longer by pushing back against the weight on the spring so that when the spring is compressed more by a greater weight, it ends up in the same position. But since all shock springs are under some constant pressure even at full extension, this adjustment increases the initial pressure on the spring, which is where the term "preload" comes from. With an air-adjustable shock, the same effect is achieved by simply using compressed air in a rubber bladder as a second spring, effectively increasing the total spring strength instead of just putting the existing spring under more pressure.

 

An ideal suspension is one that is perfectly tuned for the bike without any preload when the bike is ridden solo and unloaded. But since the solo rider can weigh anywhere from 100 to 400 lbs, no factory suspension can be properly tuned for all of us without being able to change the preload. Zero preload is usually only appropriate for the lightest of riders, not even the mythical "average" rider.

 

If the suspension is properly designed for the machine, maximum preload is the ideal setting when the bike is loaded to the printed maximum gross vehicle weight in the manual. Anything in between requires testing by the rider to determine how much preload is best for the actual weight on the bike.

 

When you throw riding style and personal preference into the mix, this subject gets much more complicated, so I think I'll just stop here.

Goose

Edited January 22, 2012 by V7Goose
clarifying with better words

[Old Texan]

Thanks Goose that was a great explanation, I'd also like to thank you for showing me around my rsv, I learned more in four hours with you then I could have discovered on my own in four years. I also took your advice and tightened up and lubed all the places you suggested, maybe one of these days it will cool off enough that we can get a group from the dfw area to go on a ride together.

 

Jim (an Old Texan)

[djh3]

Many moons ago I had a Suzuki gs 1000 that was all dressed for touring. It had air forks as well. Also in our club a buddy of mine that worked on base in the hydro shop had a bike with air forks. He built an air hose that coupled the 2 front shocks together with asingle filler port. Worked pretty dand slick. One fill port and it balanced out the two forks pressure wise. Back then nothing had air rears except maybe a goldwing.

[DanC]

Hm... sounds like most don't think this is good. If it's comfy, though, that's great. We're just over 400 pounds together.

 

I don't know how to adjust everything yet, though, and the service manual is greek to me so going to have to figure stuff out.

 

There is alot of articles wrote on the proper air and how to go about it. In no way can you use a bicycle pump. It takes a special pump. See my article under DanC concerning adjustment of air in the shocks. Hope that it helps. Read all the articles and then you will have a very good understanding of what to do and how to do it. Dan

[Shamue]

I run 0 in the forks and 25-30 psi in the shock very smooth ride. Were close to 400 lbs together

 

 

Same here almost 400# together. front at 5-7psi, rear at 25psi.

Very confortable ride for us, after 200 -300 miles she put in into snooze mode

and can sleep, usually does.