KennyWiz
Well-known member
Rear Spring: WILBERS SPRING 59-130-165 BLK
Fork Springs: FRK SPR 40.0x38.0x310 1.2kg FRSP S4031120
Thanks
Fork Springs: FRK SPR 40.0x38.0x310 1.2kg FRSP S4031120
Thanks
Busy front end after spring change
- Thread starter KennyWiz
- Start date
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Bustanut joker
Well-known member
Ken... I'm getting the feeling your tech might be clueless..
Call shock therapy in Shia town Mi or Vernon don't have a phone book handy nor his card.. It's only 25 minutes from you. The dude is the Boss suspension wise.
Call shock therapy in Shia town Mi or Vernon don't have a phone book handy nor his card.. It's only 25 minutes from you. The dude is the Boss suspension wise.
Queensland Ken
Well-known member
Sorry, forgot to mention that I had "gold valves" installed when I first had the forks serviced and bushings replaced.
Terry Hay, Shock Treatment here in Australia said to run Castrol 10 weight with the new valves.
I had the 1.1kg/mm springs installed, I have them backed well off, too stiff.
Terry Hay, Shock Treatment here in Australia said to run Castrol 10 weight with the new valves.
I had the 1.1kg/mm springs installed, I have them backed well off, too stiff.
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extrememarine
Well-known member
Kenny,
Sounds like you just need to load up and head to Cumberland Falls in 2 weeks for EOM; then you could probably persuade Mr. Ashe to take a look at it...
Just sayin'
Wayne
Sounds like you just need to load up and head to Cumberland Falls in 2 weeks for EOM; then you could probably persuade Mr. Ashe to take a look at it...
Just sayin'
Wayne
Bustanut joker
Well-known member
He's from Michigan Wayne.. He can't afford it. :lol: Food stamps don't buy Gas. 
Don't ask how I know. :blink:
Don't ask how I know. :blink:
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HaulinAshe
Well-known member
IF, and it's a big IF, I'm interpreting the numbers correctly, the rear is a Wilbers variable rate of 130-165 N/mm rate.
IMHO, you have a somewhat mis-matched front/rear. Nothing that I have not seen many times before, but something that I've seen many people complain of harsh feel to forks, especially on shallow, high-speed bumps like pavement ridges on the slab.
Couple the spring rates with (again assuming) RaceTech Gold Valves in their typical configuration, and you have too much front rebound and too much front spring for comfort. It would be a drastic change from the stock/OEM FJR setup, certainly a change that's readily apparent and not typically welcomed. The good side... bet it handles like a dream in the hard twisties.
Personally, it's likely I would never be satisfied with a variable rate/progressive rate or whateverthephuckyouwannacallit rear spring, paired with RaceTech linear springs up front. The suspension will not balance front/rear in a way that would make me happy. But I'd be willing to give it a try with a different front setup.
My bottom line recommendation... follow Bust's suggestion and find someone close to you that knows suspension well, and who is willing to listen to you and others. Sounds like you are close, just not quite there yet. You've spent hard-earned money and it could only require one or two not-so-expensive changes to make you happy enough to stop right there. It can take a lot of money to get that last 5% of the performance envelope, ask any racer.
If it were my bike, I would change the front springs to 1.0 kg/mm, switch to an UltraLight fluid of no more than 3.5 wt at 120mm, make damn sure the assembled preload is 11-15mm, and run the RaceTech valves as-is for now. With you pulling the forks, you should be able to get all that done for roughly $200, and it should be enough of a substantial change to tell you if you are going in the right direction. Oh yeah, open those clickers up front. With RT Gold Valves you should be running roughly 15-clicks on both Rebound and Compression as initial/starter settings.
One little and last long shot, and it's a far-fetched possibility, but possible...
The RaceTech Gold Valve kit includes a very sharp-tapered steel rebound control needle and a fairly weak needle spring, that can be accidentally jammed into the valve orifice resulting in a completely closed rebound circuit on that fork. It makes an ugly and harsh feeling fork.
Have your local tech check the cartridges to make sure the rebound control rods actually move up/down with "spring pressure". Never drop the control rods into the damping rod during re-assembly. Always gently slide them into the hole. Sometimes a jammed control needle will dislodge and return to working normally, sometimes not. If not, you must completely dis-assemble the cartridge and dislodge the needle from its seat.
Good luck. Hope it works out to make you happy.
I know that I shouldn't, but I'm going to disagree with Jeff Ashe on one minor point: On the subject of preload and / or spring spacers effecting the spring's stiffness.
That would only be true for a fork (or shock) with a progressive rate spring. In that case, by varying preload you would be operating in a different part of the variable spring's rate. Also, to a lesser extent, as you increase the ride height and tilt a bike backwards and place more weight onto the rear end, the front may feel slightly stiffer due to the decreased weight loading the front. So there is that.
But fundamentally, assuming we are only talking about straight rate fork springs, adjusting the preload, including doing so by changing the spacer length, will not change the spring's resistance to compress. It will only change which part of the total available suspension stroke you will be operating at dynamically (aka: ride height, dynamic sag, etc.).
I realize that this is counter-intuitive. On the surface it sure seems like if you crank down on the preload and make it feel stiffer at full extension that it should then also be stiffer when loaded, but that is not the case. It will just not be able to compress the "pre-compressed" spring quite as far as it did before. And it will stop compressing at the same spring resistance. It has to. From a physics standpoint, when you put "x" weight on a spring of "y" spring rate, the spring will always provide the same amount of resistance to the suspended weight regardless of the preload.
So, the only way to change the spring's resistance to compression is to physically replace the spring with a spring of a different rate . Which is kind of where Jeff eventually went in his post, suggesting a more "normal" rate spring up front (1.0 or 1.1kg/mm), rather than the stiff 1.2kg/mm ones that are in there now.
PS - The only reason that I suspected a dampening problem vs a spring rate issue is that in the OP KennyWiz only complained about a "busy" feeling at high speeds. I assumed that the suspension felt fine at "normal" speeds. The spring will respond to impacts the same at high frequencies and low frequencies.
Per the actually measured viscosities chart, Castrol 10 weight is the absolute thinnest (claimed) 10 weight oil on the market, and is almost identical to Yamaha 01Fork OIl, which is about a 3 weight oil in reality.
That would only be true for a fork (or shock) with a progressive rate spring. In that case, by varying preload you would be operating in a different part of the variable spring's rate. Also, to a lesser extent, as you increase the ride height and tilt a bike backwards and place more weight onto the rear end, the front may feel slightly stiffer due to the decreased weight loading the front. So there is that.
But fundamentally, assuming we are only talking about straight rate fork springs, adjusting the preload, including doing so by changing the spacer length, will not change the spring's resistance to compress. It will only change which part of the total available suspension stroke you will be operating at dynamically (aka: ride height, dynamic sag, etc.).
I realize that this is counter-intuitive. On the surface it sure seems like if you crank down on the preload and make it feel stiffer at full extension that it should then also be stiffer when loaded, but that is not the case. It will just not be able to compress the "pre-compressed" spring quite as far as it did before. And it will stop compressing at the same spring resistance. It has to. From a physics standpoint, when you put "x" weight on a spring of "y" spring rate, the spring will always provide the same amount of resistance to the suspended weight regardless of the preload.
So, the only way to change the spring's resistance to compression is to physically replace the spring with a spring of a different rate . Which is kind of where Jeff eventually went in his post, suggesting a more "normal" rate spring up front (1.0 or 1.1kg/mm), rather than the stiff 1.2kg/mm ones that are in there now.
PS - The only reason that I suspected a dampening problem vs a spring rate issue is that in the OP KennyWiz only complained about a "busy" feeling at high speeds. I assumed that the suspension felt fine at "normal" speeds. The spring will respond to impacts the same at high frequencies and low frequencies.
Ken,
Per the actually measured viscosities chart, Castrol 10 weight is the absolute thinnest (claimed) 10 weight oil on the market, and is almost identical to Yamaha 01Fork OIl, which is about a 3 weight oil in reality.
Last edited by a moderator:
KennyWiz
Well-known member
IF, and it's a big IF, I'm interpreting the numbers correctly, the rear is a Wilbers variable rate of 130-165 N/mm rate.
IMHO, you have a somewhat mis-matched front/rear. Nothing that I have not seen many times before, but something that I've seen many people complain of harsh feel to forks, especially on shallow, high-speed bumps like pavement ridges on the slab.
Couple the spring rates with (again assuming) RaceTech Gold Valves in their typical configuration, and you have too much front rebound and too much front spring for comfort. It would be a drastic change from the stock/OEM FJR setup, certainly a change that's readily apparent and not typically welcomed. The good side... bet it handles like a dream in the hard twisties.
Personally, it's likely I would never be satisfied with a variable rate/progressive rate or whateverthephuckyouwannacallit rear spring, paired with RaceTech linear springs up front. The suspension will not balance front/rear in a way that would make me happy. But I'd be willing to give it a try with a different front setup.
My bottom line recommendation... follow Bust's suggestion and find someone close to you that knows suspension well, and who is willing to listen to you and others. Sounds like you are close, just not quite there yet. You've spent hard-earned money and it could only require one or two not-so-expensive changes to make you happy enough to stop right there. It can take a lot of money to get that last 5% of the performance envelope, ask any racer.
If it were my bike, I would change the front springs to 1.0 kg/mm, switch to an UltraLight fluid of no more than 3.5 wt at 120mm, make damn sure the assembled preload is 11-15mm, and run the RaceTech valves as-is for now. With you pulling the forks, you should be able to get all that done for roughly $200, and it should be enough of a substantial change to tell you if you are going in the right direction. Oh yeah, open those clickers up front. With RT Gold Valves you should be running roughly 15-clicks on both Rebound and Compression as initial/starter settings.
One little and last long shot, and it's a far-fetched possibility, but possible...
The RaceTech Gold Valve kit includes a very sharp-tapered steel rebound control needle and a fairly weak needle spring, that can be accidentally jammed into the valve orifice resulting in a completely closed rebound circuit on that fork. It makes an ugly and harsh feeling fork.
Have your local tech check the cartridges to make sure the rebound control rods actually move up/down with "spring pressure". Never drop the control rods into the damping rod during re-assembly. Always gently slide them into the hole. Sometimes a jammed control needle will dislodge and return to working normally, sometimes not. If not, you must completely dis-assemble the cartridge and dislodge the needle from its seat.
Good luck. Hope it works out to make you happy.
Thanks but I do not have RT Gold Valves. Someone else said they did.
KennyWiz
Well-known member
59=spring diameter
130=130n/mm spring rate
165= 165mm uncompressed length
The "set" was put together using RT calculator and talking to the "Beemer Shop" who is the US importer for Wilburs.
130=130n/mm spring rate
165= 165mm uncompressed length
The "set" was put together using RT calculator and talking to the "Beemer Shop" who is the US importer for Wilburs.
SkooterG
Purveyor of Crooked Facts
Interesting. 130 N/m is the equivalent of 742 lbs/in. Which I would think is still a bit soft if you are a 330lb rider.
Peter Murray
Well-known member
Scoot , the 130 NM spring is the standard spring recomended for the Ohlins 707.. This spec spring can accomodate 2 up riding.
Our subject equils 2 good size people..
The 1.2fork spring is too stiff for this rider, Agree the rear could be soft. The mass of the rider has much more influence on the rear shock than the front forks. If the rear is undersprung the bike becomes a chopper.. = Fork rake angel increases..
On a side note ,,, Have we determined the rider sag ??
KennyWiz
Well-known member
Maybe flip the 130 and 165 around. The receipt was in German.
Anyway. I spoke with several shops, thanks all, and the consensus is too much preload up front. The spring I ordered for the forks, should have little or no preload.
I've spoken with the Tech, who is willing to work with me on this. We will start by cutting sections of the spacers, measuring sag, and ride quality. He said he would only charge me once even if we have to revisit this up to 3 times. Sounds fair to me.
I will post up the progress late next week, as that is the time I have scheduled in his shop.
I hope this helps!
I appreciate all of the time you spent helping me figure this out. :yahoo: :clapping:
Anyway. I spoke with several shops, thanks all, and the consensus is too much preload up front. The spring I ordered for the forks, should have little or no preload.
I've spoken with the Tech, who is willing to work with me on this. We will start by cutting sections of the spacers, measuring sag, and ride quality. He said he would only charge me once even if we have to revisit this up to 3 times. Sounds fair to me.
I will post up the progress late next week, as that is the time I have scheduled in his shop.
I hope this helps!
I appreciate all of the time you spent helping me figure this out. :yahoo: :clapping:
Kenny,
Before you pay this guy to do all this "work" of chopping spacers (that can't be elongated again), why not just measure and report what your sags are.
1) Put a ty-wrap around one fork leg
2) Have a helper hold the bike vertically to put all of the bike's own weight (with no passenger or luggage loads) on the suspension and then slide the ty-wrap down to the dust seal at the top of the fork slider.
3) Without bouncing the suspension and thereby disturbing the ty wrap, put the bike up on the center stand and jack up underneath the header pipes to take all of the weight off the fork. Measure this distance. It is static sag.
Now put the bike back on the ground and you and your gear (and pillion) sit on the bike and put all of your weight on the suspension, holding the bike vertical while your helper slides the ty-wrap down again. Put the bike back up and measure the distance again. This will be your Dynamic sag.
These measurements can be made for free and they will tell you exactly what's up with your spring rate and preload. Let us know what these are.
Before you pay this guy to do all this "work" of chopping spacers (that can't be elongated again), why not just measure and report what your sags are.
1) Put a ty-wrap around one fork leg
2) Have a helper hold the bike vertically to put all of the bike's own weight (with no passenger or luggage loads) on the suspension and then slide the ty-wrap down to the dust seal at the top of the fork slider.
3) Without bouncing the suspension and thereby disturbing the ty wrap, put the bike up on the center stand and jack up underneath the header pipes to take all of the weight off the fork. Measure this distance. It is static sag.
Now put the bike back on the ground and you and your gear (and pillion) sit on the bike and put all of your weight on the suspension, holding the bike vertical while your helper slides the ty-wrap down again. Put the bike back up and measure the distance again. This will be your Dynamic sag.
These measurements can be made for free and they will tell you exactly what's up with your spring rate and preload. Let us know what these are.
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azitlies
Well-known member
Well that sounds great Kenny, and I'd bet yer on the right track...
Let us know how it works out, I think yer gonna get it fixed.
Let us know how it works out, I think yer gonna get it fixed.
ionbeam
2 FUN
HaulinAshe
Well-known member
Naw, we aren't disagreeing about anything. I probably didn't express exactly what I meant. Preload effects how the spring/fork behaves/feels when it taps the top of the stroke, which is seen most often in high-speed shallow bumps like pavement ridges. That's where I was referring to. Indeed, preload has absolutely no effect on the spring's behavior at the typical sag line. It's gonna sag to balance against the load, (almost) regardless of how much preload you have.
weekend rider
Well-known member
This is how i would fix your problem, I would send my forks and and rear shock and your information and let GP suspension solve your problem. Problem solved, they did mine, experts when it comes to suspensions
KennyWiz
Well-known member
If we all had unlimited funds, we would have no issues.
azitlies
Well-known member
Naw... Haven't you heard, Kenny? Money can't buy you happiness. :nono:
But it can definitely buy you a bitchin' suspension setup.
