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How to change front fork oil 2017 FJ-09


howie333

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1 hour ago, 2and3cylinders said:

+1, which is what I initially stated.  Sag is just a way to gauge suspension action.  If it feels and works well for you (given you know what's happening technically) is what matters.  As long as it's not bottoming out, you want to use all but approximately the last 20 mm or so.  If braking dive is acceptable, which is a factor of both spring rate and compression damping, then you're in the ballpark.  Some like it stiffer with less brake dive, some want it softer.  It's all a matter of taste up to the point that the tire must be kept in constant and consistent contact with the road with the best size and shape contact patch without chatter or vibration and uncontrolled squirming.

Thanks for reply; Front fork travel is 137mm. According to Dave Moss, I should measure tube from above seal to bottom of tube and mark travel to find bottom out, and thats where I measure to tie band afaik.    

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Just came back from short ride; and adjusting this bikes suspension made a world of difference so far. I'm still left w/ 40mm to bottom out, and as I stated 40mm sag in the forks(not sure what that relates to). I'm assuming the rear preload and both rebounds I set are also good(for now), till i have more time to take it out for a longer ride on some curvy roads, but for now, i'm very satisfied, so much, I may take back my deposit on a Aprilia RS 660 I recently put down.   I still probably should change the fork oil.

Thanks again...

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Try some hard braking, like panic stops, And see if the amount of travel to bottoming out is reduced. If not back off your preload till you get about 20 mm Under very hard breaking or over sharp fast bumps.

 If you have compression damping adjustment, try backing that off as well and then tweak Out the rebound damping accordingly

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On 2/11/2022 at 2:40 PM, 2and3cylinders said:

Try some hard braking, like panic stops, And see if the amount of travel to bottoming out is reduced. If not back off your preload till you get about 20 mm Under very hard breaking or over sharp fast bumps.

 If you have compression damping adjustment, try backing that off as well and then tweak Out the rebound damping accordingly

Well; thank you for that advise. I did some hard braking and hard cornering(tail of the dragon), and forks did bottom out ! If I start backing off fork preload, I may loose the great  cornering I now have. As you know, preload is at max. I guess I'll need heavier fork springs afaIk. If so; were do I start looking ? As stated, the rear shock is set @ full soft to get required sag. Should I also be looking to replace rear shock?

Thanks again...

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13 minutes ago, howie333 said:

Well; thank you for that advise. I did some hard braking and hard cornering(tail of the dragon), and forks did bottom out ! If I start backing off fork preload, I may loose the great  cornering I now have. As you know, preload is at max. I guess I'll need heavier fork springs afaIk. If so; were do I start looking ? As stated, the rear shock is set @ full soft to get required sag. Should I also be looking to replace rear shock?

Thanks again...

 I missed that you had preload maxed out

If  You are 165 with gear then yethen yes you should probably step up to at least a .85.

 It sounds like for some reason you're shock isn't compliant enough so consider, for example, K-Tech Razor Lite or better, Razor R sprung and damped for your weight to balance out the front.  Massaging the forks is important obviously but you can't go wrong with a  decent shock.

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HI’m 163lb, and found the rear shock had the correct spring rate for our weight, but is was too long to get correct sag. 

It also had practically no damping, compression or rebound. 

And my bike only had 7000km on the clock when I bought it  

Only way to fix it was to replace it, transformed the rear  

The front originally has a progressive springs, 0.7kg/mm soft part and 0.9km/mm on the hard part, again with practically no damping. The correct spring for my weight is 0.9 but it’s impossible to get correct sag with the soft portion. They also don’t have enough oil height which makes dive even worse.

With the single rate 0.9 springs and Racetech gold valves the bike is a totally different beast,  much better over bumps, solid on turns and very low dive under brakes  

I also raised the forks 15mm on the triples to place more weight on the front wheel.

The bike now compresses evenly in hard turns, is much more stable, isn’t unsettled in bumpy corners and makes the brakes feel a lot better. You can brake and still have front suspension travel to absorb bumps.

Its a very worthwhile expense if you’re going to keep the bike  

 

 

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13 minutes ago, OZVFR said:

HI’m 163lb, and found the rear shock had the correct spring rate for our weight, but is was too long to get correct sag. 

It also had practically no damping, compression or rebound. 

And my bike only had 7000km on the clock when I bought it  

Only way to fix it was to replace it, transformed the rear  

The front originally has a progressive springs, 0.7kg/mm soft part and 0.9km/mm on the hard part, again with practically no damping. The correct spring for my weight is 0.9 but it’s impossible to get correct sag with the soft portion. They also don’t have enough oil height which makes dive even worse.

With the single rate 0.9 springs and Racetech gold valves the bike is a totally different beast,  much better over bumps, solid on turns and very low dive under brakes  

I also raised the forks 15mm on the triples to place more weight on the front wheel.

The bike now compresses evenly in hard turns, is much more stable, isn’t unsettled in bumpy corners and makes the brakes feel a lot better. You can brake and still have front suspension travel to absorb bumps.

Its a very worthwhile expense if you’re going to keep the bike  

 

 

Not sure about the tech info on these fork springs and shocks, butt I'm sure there's a fix. where's a good info and a suspension supplier for suspension upgrade ? i'm probably going to keep the bike; but also still looking at the Aprilia RS 660 as a 2nd bike, but probably dont need it, but is so desirable cause of where i live in the (smokey mountains).

Thanks again..

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I hear there is fantastic riding to be done there.

If you're not handy with suspension work, the best bet is to find a good suspension shop in your area.

There is a fix, I just gave you one option, there's no fix using the stock parts, they are rubbish.

It also depends on your type of riding, some folks don't find anything wrong with the stock set up, and some people can't tell the difference between good and bad suspension.

As long as it brings a smile to your face, it's money well spent.

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On 2/13/2022 at 12:06 AM, OZVFR said:

I hear there is fantastic riding to be done there.

If you're not handy with suspension work, the best bet is to find a good suspension shop in your area.

There is a fix, I just gave you one option, there's no fix using the stock parts, they are rubbish.

It also depends on your type of riding, some folks don't find anything wrong with the stock set up, and some people can't tell the difference between good and bad suspension.

As long as it brings a smile to your face, it's money well spent.

 

I used the Motool to set total sag(static and rider) @ aprox. 35mm rear, and 40mm front( best I could get). Right now front fork preload is maxed and bottoming out, and rebound damping is all out to right feel, and  rear shock is set @ max soft w/ rebound 1-1/2 turns out; feels right. Rider sag is 40mm for the front, and rear is 35mm. I talked with K Tech suspension today; said not to use Maxima 5w, (already bought), but to use motul 5w for proper flow rate, change springs to a .85Nm, and the razor R rear shock w/ canister $$ (not the Light); and be better to get their fork cartridges $$which come w/ the springs. Says preload not as imoprtant as dampening when setting up suspension.    can anyone comment on these recomendations please 

thanks again...

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