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Discussion Starter #201 (Edited)
Well you let me know when you can feel that change in viscosity based on the temperature of the shock...

The change in centistrokes is simply not enough to truly impact the feel of your average rider or even club racers for that matter.

In case anyone would like to know where Zaq's reference material comes from :)

http://www.peterverdonedesigns.com/lowspeed.htm
 

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Well you let me know when you can feel that change in viscosity based on the temperature of the shock...

The change in centistrokes is simply not enough to truly impact the feel of your average rider or even club racers for that matter.

In case anyone would like to know where Zaq's reference material comes from :)

Peter Verdone Designs - Low Speed Damping










don't see what's a big deal here, obviously I didn't study Ohlins fluid purposely.
yes, Pete has good table for oil viscosities and that's exactly where I got # from and Ohlins catalogs confirm his 40C #s.

LDH, you should take time and read some of his stuff, maybe you will learn a thing or two yourself. I was under impression this thread woul be equaly educational but I'm yet to see it be that way

http://www.protouchsuspensions.be/PDF/Ohlins oil.pdf
 

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Discussion Starter #204
Well the biggest problem with some people (and it seems much more prevalent with 919 owners for some reason) is that they focus way way way too hard on theory and science instead of practical application.

Ironically everybody insists on facts and hard numbers as a means of proving their mindset, but throw out an untested, unproven, home-made air intake snorkel as a "potential" performance gain and most of you start jerkin-off like it is porn :D
 

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Discussion Starter #210
I've already looked over the Ohlins spec site for a specific chart on the HO201, but found nothing, but generic graphs for the valving

Ultimately we are not going to take the time to put a brand new shock on the dyno to gain an answer that really doesn't yield any answers to benefit the majority of customers. Everyone already knows the Ohlins shock is a definite improvement period as would pretty much any other big name shock over the stock shock it comes with...
 

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McTavish
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I've already looked over the Ohlins spec site for a specific chart on the HO201, but found nothing, but generic graphs for the valving

Ultimately we are not going to take the time to put a brand new shock on the dyno to gain an answer that really doesn't yield any answers to benefit the majority of customers. Everyone already knows the Ohlins shock is a definite improvement period as would pretty much any other big name shock over the stock shock it comes with...
Understood, reasonable and yes for sure.
 

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Bump. Is the final product sold as a kit?

Also, does the fork preload have anything to do with brake dive?
I bought mine as a kit that was completely installed at Kyle racing. I just sent in the tubes, they did the magic and sent them back to me.

Brake dive is not fixed by changing preload. The more preload, the higher the front chassis rides BEFORE it dives, but, it still dives. The problem is the lack of appropriate compression dampening, and that's exacerbated slightly by relatively weak springs...but, turning your preload setting up isn't going to correct the problem. :no:
 

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There is a lot more to come on this thread as we are documenting and entire shock rebuild as well as fork rework, but I figured some of you might be interested to see the actual rate of the OEM 919 fork spring.

In truth the spring is not as non-linear as this graph would make it appear. The lightness of the spring combined with the length of it causes it to move a little more than we would like it to and of course the massive sensitivity level of the spring rater we use feels everything. Splitting the difference it would appear the rate of the OEM springs is somewhere around 7.3Nm

Just pulling this up to later piggy back on re some front spring checks I recently did.
Stay tuned.
 

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McTavish
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There is a lot more to come on this thread as we are documenting and entire shock rebuild as well as fork rework, but I figured some of you might be interested to see the actual rate of the OEM 919 fork spring.

In truth the spring is not as non-linear as this graph would make it appear. The lightness of the spring combined with the length of it causes it to move a little more than we would like it to and of course the massive sensitivity level of the spring rater we use feels everything. Splitting the difference it would appear the rate of the OEM springs is somewhere around 7.3Nm

First off, lets again thank LDH for even doing the test.
Next, allow that it is a simple force reaction vs displacement curve.
It does not account for whatever the friction component is as function of the unit being in acceleration or at constant velocity.
This is not a criticism, just a simple observation and I have no idea as to what the friction component might be.
Obvious is that the springs are extremely soft in the initial and normal travel zone.
Note the chart goes to 60 mm of travel, while displaying a noticeable upwards slope.

Now have a look at the attached pictures.
Then allow that total travel is 109 mm

The shorter spring is out of rickards 2002 fork set that he loaned me for a look see.
The longer one is from the stockers I removed from my 05.
Both are obviously classic dual rate springs with one transition wind between the two spring wind pitch zones.
My guess is that the spring change came in 2004 when the adjustable front came out.
The 02 has 7 tight coils and 24 in total, with a free length of 281 mm.
(I'm assuming no sag over time, and the spacer lengths support this)
The 05 has 8 tight coils and 23 in total, with a free length of 302 mm.
(I'm assuming no sag over time, they have little time on them)
See how the shorter spring actually has one more coil in total, but has one less coil in the lower portion where the coils are closer together.
I didn't check the overall wire length, but sense that they are not that much different, for sure no day and night difference, and as long as there is no coil bind, total wire length dictates the overall spring rate.
It appears that Honda got Showa to retune the front springs to alter where in the stroke that lower coil bind begins, and what the revised rate is once the lower portion is in coil bind.
For sure, the effective front spring rate at 100 mm of travel will be way more than LDHs chart depicts.
The short story is this :
Insanely soft mush spring in the normal range of travel designed for a plush ride.
Stiffer spring rate once into significant travel, otherwise the suspension would be out of control and clanging the hard mechanical stop.
If one is happy with the stockers, ride on !
If you want more front end stability and less bobbing about, and do any degree of "sport riding", get yourself as set of stiffer springs.
Look at this way, LDH's chart shows a nominal 7.25 N/mm = 0.74 kg/mm rate.
Meanwhile, I'd suggest that a reasonable range of rates that many sporting or high gross weight riders would be happy with, would be in the nominal 0.90 to 0.95 kg/mm zone.
By the way, coil bind reduces the effective total spring wire length, thus increasing the spring rate.

Late addition : I just did a crude check and now ballpark the 05 spring as being about 5 % softer than the 02 spring BEFORE coil bind effect and about 5 % stiffer AFTER coil bind effect.
 

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McTavish
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Thank you LDH
I wish I had looked at this closer when he did the test, because I would have asked him if he could still easily redo it and check through all of the travel.
But even so, one can figure out lots from looking at the springs and his test results.
Fascinating stuff.
 

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I've been saying this for a while....... my '03 with stock suspension could be pushed pretty damn hard. It never made any sense to me when people would say the bike was soft. With the stiff rear shock --- the bike also liked to turn-in quickly.

Granted....after about 70%......the rear end would wiggle/move on you pushing out of a corner, the high-speed compression at times was bone jarring, and you had to be smooth on the brakes with the softer front non-adjustable forks......

The '03 rear shock was so stiff.....that when I went with an aftermarket rear shock that was sprung for my weight...... I had to use rear ride height and drop the forks in the triples a little bit to get my quick steering back.
I think I feel this sluggishness too after putting on an ohlins unit. A little more reluctant to turn.
 
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