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The question no one seems to answer

nando

nando

Crotch Rocket
If one lowers the C14 one inch with link, how can the suspension be adjusted to sort of compensate for the loss of sag on the rear?

I understand that the C14 rides better OEM, but is there anything that can be done with the stock suspension to help it suspend it after a lowering gig?

PLEASE: no sermons on the evils of lowering kits--thanks! I am already saved!
 
    I have not installed lowering links in my C14, but I'll take a shot at it. Of course my thinking may be wrong so take it with a grain of salt. I do not claim to be an expert on the subject, but have lowered front ends before for quicker turn in.
    You could slide the forks up a little in the triple trees to compensate and level out the bike a little. I do not see how the lowering link would actually take away from the shock travel. So it probably wouldn't effect sag other than being lower to begin with. But the bike would be lower effecting both ground clearance and the bikes designed geometry. So it will probably effect handling. It will definitely make you pegs drag much quicker. But the shock travel should remain the same (as far as I can think of).
  I personally try to avoid changing (lowering) the geometry of the motorcycle if at all possible. There "could" be safety ramifications involved with doing such. So I would try to go other routes first if at all possible. A lower seat or boots with bigger soles can make quite a difference.
  But if you do or already did lower the rear of the bike, I personally would suggest lowering the front end by sliding the forks up a half inch or so to balance it out.  Unfortunately it can be part of a curse of being short legged and riding a tall bike. So although I do not try to preach, I understand folks need to do what they need to do. But I personally would try other avenues first if possible before changing the bikes geometry. Of course this is just my opinion.
 
If you're using a link, I'd think setting the sag wouldn't change much, if any.  How about some cool platform riding boots instead?  :))
 
Yep - if lowering via a link, sag doesn't change.

Think of it this way - sag is set really based on your weight or the load - NOT how high you want to be above the ground.

A lowering ling doesn't alter this in any way.

To compensate in the front, the only proper approach is to reduce front height without altering the preload, sag, etc. Sliding forks up the clamps is the only way I can see accomplishing that.

Slide them up the same distance that your link lowers the bike. This isn't exactly right, since the forks represent the hypotenuse of the triangle, while the lowering link alters vertical height, but it'll be pretty close. (Remember Pythagorean Theorem - A squared+B squared=C squared)

So if link lowers rear by 1", you want to lower the stem head 1" also. If you move the forks in the clamps 1", you won't get 1" vertical lowering, you'll get 1" change in the hypotenuse, and less in the vertical leg of that triangle. You'll need more than 1" change in the fork to get 1" vertical lowering.

Without doing the math, I'm guessin 1.5"-2" in the clamps would give you 1" in stem head lowering. Surprisingly changes in the legs of the triangle can represent much larger changes in the hypotenuse (roughly 2x, depending on the triangle).

I'd do it the low-tech way - measure frame height front/rear before the lowering link, then make them the equal after lowering link.




Lowering height
 
I agree, Bob.

I am one of the metioned cursed ones, and since I will NOT give up my Baldwin GT saddle, I had to come up with another solution.

First, I put away my racer-wannabe very expense boots, and started wearing a nice but not stylish pair of boots with thick soles and heels. Better, but not enough.

So I put the Muzzy lowering links on the back, and raised the fork tubes 3/4" in front. Lo-and-behold, the bike feels the same as it did before the lowering, except for what Bob mentions. Pegs touch down sooner.

Last season at one event I went for a ride with the fast kids, and the only reason I couldn't keep up consistantly was the pegs started to get beveled on the outside bottom edges. LOL. So I backed off,
 
i don't want to get into a math debate but i am not sure how the math of the pythagorean formula, which applies to a triangle that must have a 90 degree angle, can apply to fork height adjustment.  however, if i am wrong and motorcycle suspension engineers do use the formula, i strongly believe dropping the front forks 2 inches, will result in some huge potential problems.  first a very big riser will be needed for a 2 inch fork adjustment. this will dramatically raise the bars and change the "feel" and probably make counter steering less natural.  this could as require new cables , wiring,etc.    obviously, ground clearance will get very dicey.  the peg feelers are there by mandate of the dept. of transportation. after you touch those feelers, you must design in at least 2 extra degrees of "lean angle" on any bike sold in the u.s.  this was told to me by a motorcycle suspension engineer. i would guess the connie has much more of a safety margin, since the bike will be invariably overloaded by some riders, especially 2 up.  but unless you ride like a  boss hog rider, you will eventually drag hard parts.  i have dented front fenders on some bikes when i did not have enough spring preload and compression damping. i could be wrong and i am not going to the garage to check my 2011, but i would check fender clearance on hard braking, if you drop 2 inches.  many fork tubes have different diameters as you move down the tube.  this may be a built in safety factor to prevent radical fork adjustment, which i consider a 2 inch drop to be.  it may be it was on the early zx-14's, and not on early 2nd gen. connies, but guys did lower too much and when hitting bad bumps sheared their oil plugs off.  the plugs were relocated to the side to "fix" that problem.  however, lowering any bike too much, back and front, you may end up banging you underside if you live/ ride on bad roads.  i am not  a suspension expert but a 2 inch drop in front is a very big and risky move.  i dropped my rear with the muzzy dogbones and left the front alone. the bike still handle fine, with no ill effects. ground clearance did diminish, but the sliding forward onto the tank was considerably improved, along with getting my feet down.  if you do need to drop the front i would go slow, like a quater inch at a time until you feel comfortable.  when you get over  a half inch, i would start thinking a low seat and maybe bigger boots. 
 
I dropped the Honda VFR 11/2 inches in the rear and 13/4 on the front to help Lisa flat foot it.
It felt fine to me but she always complained about the nose feeling hoppy especially uphill.
With the Givi bags on and loaded along with a dry bag for camping she said it was almost unsafe to ride.
My thought is with the front pushed down that has the effect of pushing the handlebars up, This transferred even more weight rearward making the front too light.
As soon as I set it back to factory specs she was happy again.
 
I 'll chime:

Consider a 1 inch lowering link from Precision engineer.
Lowering the rear makes the fork rake longer...which in my handling view, does have a negative impact on the efficacy of the C14 handling. The handlebars require more input, it does not flow around the arc of a turn as smoothly; I am gonna guess because the rear tire is not tracking (the front tire) like it was designed to do.

On the positive side, I think the bike sits on the freeway better and there is less, or none, of the front braking diving on the front forks. Long wheel base ride the slab better than shorter. And if you like this sort sitting arrangement, you sit 'inside' the bike more.

BUT MY QUESTION WAS: how does one adjust the suspension to compensate for lowering the rear 1 inch? Is it possible? The sag and the Rebound?

tis the reason for the title of this thread: no one seems to have an answer for that question.

In fact, the question is compounded by the suggestion to raise the forks (lowering the front end) cause now suspension adjustments may be more intricate with both ends lowered...which takes one back to a crouch-rocket position with less efficient suspension.

I enjoy only the rear end lowered (but then again, I am an old chopper jockey). Its a dilemma for me cause I also enjoy the OEM maneuverability very much.

Fred! help us out here buddy



 
slider said:
i don't want to get into a math debate but i am not sure how the math of the pythagorean formula, which applies to a triangle that must have a 90 degree angle, can apply to fork height adjustment. 
Click to expand...

Easy one to answer Slider - the forks are at an angle, that angle forms a triangle with a vertical line through the stem, and a horizontal line through the axles.

Lowering the front 1" means reducing the length of the vertical line through the stem by 1", not the length of the forks by 1". Shortening the forks 1" wouldn't reduce height by 1", but by a ratio determined by the formula.
 
how does one adjust the suspension to compensate for lowering the rear 1 inch? Is it possible? The sag and the Rebound?
 
nando said:
how does one adjust the suspension to compensate for lowering the rear 1 inch? Is it possible? The sag and the Rebound?
Click to expand...

Already stated, above. It doesn't change.

If I could keep up with the fast kids other than dragging the pegs too much to keep doing it, without changing anything but putting the lowering links on and raising the fork tubes 3/4", my opinion is, if the suspension worked any better, it would be a sport bike. Which it isn't.
 
nando said:
how does one adjust the suspension to compensate for lowering the rear 1 inch? Is it possible? The sag and the Rebound?
Click to expand...

In a nutshell Nando, move the forks in the clamps until the bike is level again.
 
Hi Nando. 

I think I understand your question....you are looking for a way to compensate for the loss of ride height after installing the lowering link....right?  It seems the only way to do this would be to install a stronger spring that would resist compression.  I think if you were to increase preload on the stock spring....it would reduce the benefit of the lowering link.  You also suggested increasing compression....which may help prevent bottoming on bumps but it would also compromise ride quality.  Well....a stiffer spring would also impact ride quality (bump compliance) as well.

Sorry I don't have any good suggestions but I think I understand what you are trying to accomplish.
 
Soda,
You are getting warm....

its a consensus that Connie loses comfort on the suspension when one lowers it....therefore, my question (which if you noticed, no seems to address precisely) is how can one adjust the sag and preload in a way tha would get back to as nearly as possible, to the comfort of the OEM setting?

It appears to me that no one seems to know...I asked Fred to chime in since he has done quite a bit of data gathering on adjusting the suspension to rider-weight...but he appears to not want to do anything with lowered  bikes
I am stillnin the dark...I am leary of starting to turn knobs to experiment because given my extensive expertise on suspension, one can almist bet that I am going to screw up something--or make it worse

right now I am running the settings suggested by Fred for an old fart with a boyish figure of 180 lbs
 
Ahhh..now I see...


Sorry Nando - I misunderstood your question, and assumed you meant merely get the bike back to level (since the rear was lowered) -  how to lower the front equally.

Now I get that the question is since the bike is lowered by the link, how do you get the ride back?

From what I've seen of lowering links, they just change the relative position of the trailing link/swing arm, but not geometry. I'm not sure how this reduces ride quality (since geometry really isn't changing, and more importantly spring rates aren't changed), other than to reduce the total range of motion of the swingarm (because it's now closer to the fully-compressed position). The rates/rebound damping should work the same, you just get to the fully-compressed position faster (bottoming out).

In theory, reducing the range of motion means that the suspension will now have to absorb shocks in a shorter distance and therefore time interval, requiring higher damping rates (i.e. higher spring rates and rebound damping), if you want to avoid bottoming out.

Ideally the way to address this is with a rising-rate spring designed with that range of motion and the bikes' weight in mind, and a shock tuned for this with the proper rebound damping rates. Short of the proper spring, preload is the way most people "cheat", which simulates adding spring rate (by preventing sag) to the beginning of suspension compression - when what's needed is an increase in spring rate as it approaches maximum compression. Adding preload is why you get the harsh ride. Unfortunately, while increasing preload will reduce bottoming out, it'll make the bike more "bouncy", especially without altering the rebound rate.

With this kind of mod (lowering) on cars, one approach is to add "stoppers", or rubber bumpers on the control arm (swing arm on a bike) that only contact the frame at the limit of suspension compression. (Cars come with these from the factory, some bikes do too). The add-on stoppers are designed with a specific density to provide a known compression rate. By only engaging at peak suspension compression, they effectively provide the additional spring rate needed then. This allows for use of the standard spring with normal/proper preload setting...but rebound damping still needs to be altered.

At a minimum, avoid the temptation of increasing preload in an attempt to prevent bottoming out. If anything, I'd consider reducing rebound damping some (the C14 has this adjustment ability, doesn't it?), to allow the suspension to re-extend more quickly. You'll still bottom out more often, unless you do something to increase spring rate (such as add a helper spring or stoppers).

Good luck, and keep us posted on your progress!

 
Thanks Jim,

I think I understand the situation more clearly now. I would be afraid to increase the sag as it would make it more likely to bottom...I may try loosening the rebound, but I guess that would cause the same problem.

The fact is this bike rides better OEM...but it sure is more comfy to peddling lowered... and less susceptible to dropping


I don't believe the C14 has dampening adjustment.

What a dilemma!...I think lowering the front would really make the bike ride rough, would it not? should I try that in order to gain back the plushness of OEM suspension?
 
  Screw Pythagoras,  he's not getting anywhere near my bike.  And what is this talk about hypmo-tizing a moose, thats just crazy talk! 
 
nando said:
Thanks Jim,

I think I understand the situation more clearly now. I would be afraid to increase the sag as it would make it more likely to bottom...I may try loosening the rebound, but I guess that would cause the same problem.

The fact is this bike rides better OEM...but it sure is more comfy to peddling lowered... and less susceptible to dropping


I don't believe the C14 has dampening adjustment.

What a dilemma!...I think lowering the front would really make the bike ride rough, would it not? should I try that in order to gain back the plushness of OEM suspension?
Click to expand...

Lowering the front will just get the bike level - shouldn't have any more influence on ride than lowering the rear (same issue - risk of bottoming out more readily). Though I think the forks have a little more flexibility there. Keeping in mind that without lowering the front you've effectively increased the rake angle - which will make the steering slightly less responsive (it's probably not a huge diff).

If you keep the preload setting to prevent bottoming out, you're pretty much stuck with the stiffer ride, and rebound will need to be set accordingly (just high enough to prevent oscillations).

Yea, it's a no-win without altering the spring rate.
 
WaltR said:
  Screw Pythagoras,  he's not getting anywhere near my bike.  And what is this talk about hypmo-tizing a moose, thats just crazy talk!
Click to expand...


Bwahahahahahaha!

Dang mooses, always messin' with my pythons!
 
Lowering your forks too much would make slot of changes
too your suspension. One safety problem would be
A bad headshaker on deceleration. Because your
changing wheelbase, amount of weight on the ends
Of suspension. And the turning angels of which I know
Little. :-\
 
nando said:
how does one adjust the suspension to compensate for lowering the rear 1 inch? Is it possible? The sag and the Rebound?
Click to expand...
It's not possible. At least not with the OEM shock. By changing the link you've altered the spring and damping rates at the wheel. No amount of adjustment on the stock shock is going to compensate for that.
 
JimBob said:
WaltR said:
  Screw Pythagoras,  he's not getting anywhere near my bike.  And what is this talk about hypmo-tizing a moose, thats just crazy talk!
Click to expand...

Bwahahahahahaha!

Dang mooses, always messin' with my pythons!
Click to expand...

Well since silly talk seems to be allowed; really, what's so bad about platform boots? Solves the problem. Make 'em clip on style that attach to your favorite boots,
and just take them off when you stop to eat.  (I'm actually quite seriously thinking about this one  :-\)
OR.......hydraulic lowering links that only lower the bike at less than 5mph.
OR....a lower seat that has an embedded AirHawk that inflates and deflates when crossing 5mph.

Once again, I wish one of you would start making and selling the crazy stuff I can dream up. ::)
 
Ok here s  the possible conclusion to this drama:

Given all the advice, knowledge and jokes expressed on this thread, I deducted that turning my rebound adjuster on the shock a quarter of turn to the left...looser...would do 'something good'...like allow the rear shock to talk to  the sag setting and work with mutual collaboration a bit more efficiently

Lo and behold! the rear suspension is working mucho better ... when I pay attention.... the beauty of the thing is that I don't even notice it anymore whereas before the adjustment I could not get it off my conscious awareness...cause it was more harsh than the stock...

wanna hear another crazy thing? I think the front forks actually work better with the slight minimal rake the lowering kit gives it. Now, the front shocks seem to hit the bumps is a way that allows the fork to take the hit at a better angle...better than the stock fork rake where the wheel is more tucked inward for quicker transitions. If you think about the geometric of the impact of road bumps on the fork this may even make sense to you...though I am not responsible for any psychological disturbance this perception may cause.

I wish I could research this with some viable tools, but all I got to show is my blabbering!
 
nando said:
Lo and behold! the rear suspension is working mucho better ... when I pay attention.... the beauty of the thing is that I don't even notice it anymore whereas before the adjustment I could not get it off my conscious awareness...cause it was more harsh than the stock...

wanna hear another crazy thing? I think the front forks actually work better with the slight minimal rake the lowering kit gives it. Now, the front shocks seem to hit the bumps is a way that allows the fork to take the hit at a better angle...better than the stock fork rake where the wheel is more tucked inward for quicker transitions. If you think about the geometric of the impact of road bumps on the fork this may even make sense to you...though I am not responsible for any psychological disturbance this perception may cause.
Click to expand...

:rotflmao: :rotflmao: :rotflmao: :rotflmao: :rotflmao:
 
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