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Old September 11th, 2013   #21
JZH
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Default Re: The jokes on me

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Originally Posted by PaulRB View Post
Look no farther than the OEM springs in the ST's front forks for a progressively wound spring.

I do not think I have seen a CBR with progressively wound fork springs.
We not not get the NSR.
The VFR has a cult like following in the U.S. but is not a big seller.
A shame really but fear of V-Tech is only exceeded by lack of knowledge on V-Tech.
Thanks for the info on the OEM ST1300 fork springs; as I said above, I never managed to replace mine with Sonics, so I've never seen any in the flesh.

So, I guess your point is that it would not be useful to install adjustable pre-load adjusters on forks that use progressive springs? I'm still not sure why you think so, but it is ultimately irrelevant, as I would never have kept the OEM springs (or switiched to Progressive or Hyperpro) even if I had managed to swap the fork caps for the RR ones. It simply would not make sense to me to go to the trouble of adding pre-load adjustability without changing to springs more appropriate for my weight, and pre-setting the pre-load internally using spacers.

I suppose if you assume that someone would just swap fork caps and do nothing else, your comment does make some sense.

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Old September 11th, 2013   #22
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Default Re: The jokes on me

I believe what I said was the adjuster on the fork cap is for fine tuning.
Fine tuning would imply you have the suspension set up for your weight and riding style.

Paul
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Old September 11th, 2013   #23
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Pre-load adjustments on the ST take serious movement in the springs from stock. Progressively wound springs do not lend themselves to the type movement required to make any difference in adjustment at the cap.
I was just trying to understand if there was any reason why pre-load adjusters would not work effectively on progressively wound fork springs. I had never thought about it before, but it had seemed to me that such adjustment would work the same as on any other type of spring. Thanks for clarifying.

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Old September 11th, 2013   #24
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Default Re: The jokes on me

It was explained to me long ago this way and it is fairly simple to understand.

Think of the spring as a wire standing straight up and down.
Push down on the wire and it is difficult to move the wire.
As you start to lay the wire over it gets easier to push it down.
Now coil the wire.
The farther between the coils the straighter the wire the harder it is to push the wire down. Higher spring rate.
As the distance between the coils decreases the easier it becomes to push the wire down. Softer spring rate.

As weight is applied the coils become closer to the point they touch. Coil Bind.
It is at that point that if the same amount of weight is still applied the coils wound farther apart from each other start to move.
This action could go on to the next section wound still farther apart and so on until the coils are completely collapsed. This would be just beyond the final spring rate, basically a spacer.
Several way this can be done to include using differing size wire in the coil but the effect remains the same. The closer the winding is the softer the spring rate.

Tighter wound coils must be almost to fully collapsed before they will bind and in effect become a solid spacer moving the wider wounder coils and causing a change in spring rate. This is the reason adjusting through the fork cap has so little effect on pre-load. It takes almost complete binding of the soft end before the wider coils have any effect. The fork caps offer very little movement simply because it would take a threaded screw so to speak of some length to move the spring enough to cause any real change.

All of this is a lot easier to explain with pretty pictures drawn on bar napkins but imaginary beer will have to do.

Paul
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Old September 11th, 2013   #25
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Default Re: The jokes on me

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Tighter wound coils must be almost to fully collapsed before they will bind and in effect become a solid spacer moving the wider wounder coils and causing a change in spring rate. This is the reason adjusting through the fork cap has so little effect on pre-load. It takes almost complete binding of the soft end before the wider coils have any effect. The fork caps offer very little movement simply because it would take a threaded screw so to speak of some length to move the spring enough to cause any real change.
I understand the theory, but as I have already mentioned, there are many Hondas with OEM pre-load adjusters and OEM dual-rate springs. The VFR750F, for example, did not have the adjusters in 1990-91, but they were added to the 1992-93 models, which tends to suggest that their inclusion was not a mistake. Adjustment may not have as pronounced effect as if the springs were straight-rate, but they must have some effect on a dual-rate spring, so I cannot see any reason why they would not have a similar effect on a progressively wound spring.

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Old September 11th, 2013   #26
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Default Re: The jokes on me

And the beat goes on.

Keep explaining until we all understand it, not just those in the know.
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Old September 11th, 2013   #27
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Default Re: The jokes on me

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Some type risers would have been required to gain access for adjustment but two issues with simply replacing the fork caps exist.
First and foremost the caps require the internals to adjust. The ST's forks do not have the required plumbing to adjust damping.
Second the fork caps are for fine tuning. Pre-load adjustments on the ST take serious movement in the springs from stock. Progressively wound springs do not lend themselves to the type movement required to make any difference in adjustment at the cap.

Any adjustments for any reason (pre-load, damping) on the front end of the ST require kits (more than one) of some form. Pre-load will require springs. Damping will require Gold Valves or replacement cartridges that are adjustable.
Kitting the ST is not cheap but it can and will make a huge difference.

Out back the shock is preload and compression damping adjustable but it also comes with problems.
The shock is seriously under-sprung and that seriously affects any damping adjustments. Kitting it is not cheap and can not be done at home (Race Tech). Replacement shocks are not cheap $700-$1,200 is the norm.
Again you get what you pay for at the higher end here.

A fully turned out ST $3,000. Only the serious need apply.

Paul
To clarify a couple things longer spacers add preload even with progressive springs. Adding 16 mm longer spacers raised my ride height 12 mm. With progressive springs the change is not linear but does not suggest the tighter coils are coil bound either. Secondly the rear shock is adjustable for rebound not compression damping.

The bike is under sprung only if you weigh more than the ideal rider Honda had in mind. Checking free sag against static sag indicates if the springs are on the ball park. If one is light and packs the same the spring rate is acceptable.

It annoys me that the experts immediately say you must spend lots of money [with me more than likely] on the suspension before they ask what do you weigh and what are your sag numbers?
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Old September 11th, 2013   #28
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Default Re: The jokes on me

Thanks. Rebound--I knew that. Compression--I wrote that. I'll change it.

I do not believe I have met the rider that is the correct weight for the suspension on either end of the ST. I have met more than a few that the 1.2 front springs are not enough. Seeing the loads on some of these things I do not think that make enough spring.

Even if you know someone that can set up the ST with the stock suspension there is enormous room for improvement in the ride.
Not all that that improvement cost lots of money.
The $3,000 dollar suspension setup is state of the art high end equipment that the majority do not need or will use.
With that said $3,000 to set up a $20,000 bike you plan to ride and keep is not the worst money you will spend.

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Old September 12th, 2013   #29
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Default Re: The jokes on me

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Keep explaining until we all understand it, not just those in the know.
I think Paul's was a good, clear explanation. I usually start with the example of a torsion bar, which are used on some cars in place of coil springs, but that probably works best with people who know what one is!

Ciao,
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Old September 12th, 2013   #30
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Default Re: The jokes on me

My first car, a 1968 MG, had torsion bar front suspension.
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