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Cruisin above overcast.
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Discussion Starter · #1 ·
Hi all - I love the 900c, and it handles better than I thlought it capable of when I bought it, but I have one issue/complaint. Front end dive. I ride 2-up a lot and have the rear spring adjusted to 2nd highest setting. I like the bike fairly stiff, and I feel it handles better that way for me. But the front fork feels so mushy at times, and I wish I could firm it up. It there anything I can do to the stock forks to remedy this? I am mechanically inclined but have no experience with bike forks. Thanks...
 

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fork

Hi all - I love the 900c, and it handles better than I thlought it capable of when I bought it, but I have one issue/complaint. Front end dive. I ride 2-up a lot and have the rear spring adjusted to 2nd highest setting. I like the bike fairly stiff, and I feel it handles better that way for me. But the front fork feels so mushy at times, and I wish I could firm it up. It there anything I can do to the stock forks to remedy this? I am mechanically inclined but have no experience with bike forks. Thanks...
you can switch to heavier fork oil, not to involved. Or get some gold Valve emulators, a little more involved
 

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Crazy Old Guy
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When I purchased my cruiser, I was appalled at the lack of adjustability of the suspension. I came from motocross bikes and they are fully externally adjustable, so I returned to my old days of riding (70's, 80's) and remembered how we used to do it.

The cheap way out is to fabricate a spacer to sit on top of the springs to give the springs more preload, this will help the initial dive (compression stroke). Adding thicker viscosity fork oil will slow the speed of the dive and the return stroke, but can also increase the rigidity of the ride. More fork oil will only help if you are bottoming your forks on a regular basis (not common).

I have looked into aftermarket suspension products and am disappointed at the lack of products available for our beloved cruiser. Progressive makes an adjustable rear shock for about $1K. Fork springs should be readily available if you have the stock length and sprint/fork diameter size, but I haven't found any that fit our bike by application.
 

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Cruisin above overcast.
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Discussion Starter · #6 ·
Thanks pred but no, the bike can be improved IMO. I will look in to fork oil viscoscity and spring preloading. it has never bottomed out, just I am big on lg % front wheel braking and i want it to dive less. rear stifnes is great, more in front would be perfect.
 

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Premium Member
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I know Ohlin has fork springs (and shock) for the 900. Progressive is suppose to have them available soon.

Product search - Öhlins

When the 900 first came out the most complaints from the reviewers was regarding the poor suspension. I expect if I keep mine awhile longer I will also be in the market for a new shock/springs.
 

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Need Time To Ride
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I have Progressive springs in my 07 Custom. You can change the pvc spacer to adjust the ride. My dives but it's set soft to deal with the rough roads. The springs are supposed to be soft initially to soak up bumps. Much better than the stock springs.
 

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Nobody Home
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You can change the pvc spacer to adjust the ride.
the bike can be improved IMO. I will look in to fork oil viscoscity and spring preloading. i want it to dive less.
Changing the preload spacer just changes the ride height.

Easy things to start with are oil viscosity and level. Heavier oil will make them stiffer. Higher levels will make them more progressive, until the levels are so high you no longer use the travel and the forks hydraulic lock. It would be worth starting by checking the oil levels and bringing them up to spec if they're not. Common. If the fork oil has never been changed it would be worth changing and trying slightly heavier oil at stock levels. You can try raising the levels 1/2", but you have to be carefull because too high levels will just limit travel.

Springs are an option but frequently levels and viscosity do wonders if you're a little mechanically skilled.
 

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Army Strong. Ride Long
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Changing the preload spacer just changes the ride height.
Don't know if I agree with that statement. I mean, the spacer is internal to the tube and just applies more or less pressure to the spring. The over all height of the ride (at fork position) should change from an internal modification. The spring will just compress or relax more. According to the people at Progressive, making the spacer shorter (i.e., less pressure on the spring) will decrease preload, making for a softer ride. Increasing the spacer (i.e., pressing more on the spring) makes for a stiffer ride. They recommend not deviating more than a 1/2 inch either way.

I really like the feeling my progressive fork springs give my 1600. A lot less front end plow, less nose diving and RR crossings are a breeze.
 

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Workin' to ride
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Don't know if I agree with that statement. I mean, the spacer is internal to the tube and just applies more or less pressure to the spring. The over all height of the ride (at fork position) should change from an internal modification. The spring will just compress or relax more. According to the people at Progressive, making the spacer shorter (i.e., less pressure on the spring) will decrease preload, making for a softer ride. Increasing the spacer (i.e., pressing more on the spring) makes for a stiffer ride. They recommend not deviating more than a 1/2 inch either way.

I really like the feeling my progressive fork springs give my 1600. A lot less front end plow, less nose diving and RR crossings are a breeze.
Thanks for that explanation Mark...
 

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Nobody Home
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According to the people at Progressive, making the spacer shorter (i.e., less pressure on the spring) will decrease preload, making for a softer ride. Increasing the spacer (i.e., pressing more on the spring) makes for a stiffer ride. They recommend not deviating more than a 1/2 inch either way.
Yes and no. Shorten the spacer(s) 1/2" and the forks will sit 1/2" lower. How much preload is on the spring will determine how far the forks compress with a given weight. That determines ride height. In this case it also makes the forks easier to bottom because you have 1/2" less travel before they hit the bottoming stops so they feel softer, bottom easier. You try to strike a ride height balance between bottoming and topping.

It's like carrying a passenger. You crank up the rear spring preload to raise the back end of the bike back up (ideally) so the bike sits the same height it did with just you on it. You didn't really "stiffen" the rear end, you adjusted the spring preload (and ride height) so you're back at the same point in the suspension travel. Your passenger gets off, and, if you don't re-adjust the spring preload, the rear end sits high (ride height) and feels stiff. It isn't "stiffer", it's just too topped out in the suspension travel so the suspension doesn't work properly. The springs haven't changed, they're the same rate, just the preload (and ride height) is different.
 

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Workin' to ride
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559 Posts
Yes and no. Shorten the spacer(s) 1/2" and the forks will sit 1/2" lower. How much preload is on the spring will determine how far the forks compress with a given weight. That determines ride height. In this case it also makes the forks easier to bottom because you have 1/2" less travel before they hit the bottoming stops so they feel softer, bottom easier. You try to strike a ride height balance between bottoming and topping.

It's like carrying a passenger. You crank up the rear spring preload to raise the back end of the bike back up (ideally) so the bike sits the same height it did with just you on it. You didn't really "stiffen" the rear end, you adjusted the spring preload (and ride height) so you're back at the same point in the suspension travel. Your passenger gets off, and, if you don't re-adjust the spring preload, the rear end sits high (ride height) and feels stiff. It isn't "stiffer", it's just too topped out in the suspension travel so the suspension doesn't work properly. The springs haven't changed, they're the same rate, just the preload (and ride height) is different.
That helps me understand too. What do think the preload should be set at for a 160 lb rider with an occasional 115 lb passenger on a stock suspension 900 custom? What is the factory setting?
 

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Crazy Old Guy
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1,189 Posts
. . .

It's like carrying a passenger. You crank up the rear spring preload to raise the back end of the bike back up (ideally) so the bike sits the same height it did with just you on it. You didn't really "stiffen" the rear end, you adjusted the spring preload (and ride height) so you're back at the same point in the suspension travel. Your passenger gets off, and, if you don't re-adjust the spring preload, the rear end sits high (ride height) and feels stiff. It isn't "stiffer", it's just too topped out in the suspension travel so the suspension doesn't work properly. The springs haven't changed, they're the same rate, just the preload (and ride height) is different.
I don't want to beat this horse too much, but you are not totally correct. Specifically on the 900, if you only adjust the rear spring preload, you have only affected loaded preload, not raised the rear of the bike. The shock only has a certain free length, more preload on the spring allows more of the shock travel to be available to cushion your ride. In other words, the shock only has a certain amount of travel. Too little preload on the spring will use up most of the available shock travel just by sitting on the bike. Conversely, too much spring preload will leave most of the available shock travel, but at the expense of a plush ride as the valving on most shocks is stiffer the more that it is compressed.

The front fork internal spacer works the same way. The forks don't get physically longer, the spacer takes up any slack created by sagging springs and adds preload to the spring.

Too much or too little preload depends on the rider. I prefer a slow rebound and soft compression, but don't want to spend $1500 to customize my suspension just yet.
 

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Crazy Old Guy
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That helps me understand too. What do think the preload should be set at for a 160 lb rider with an occasional 115 lb passenger on a stock suspension 900 custom? What is the factory setting?
The factory setting for the rear shock is number 4 (max is 7). If your passenger does not complain about bottoming, or really harsh 'butt jolt' when hitting pot holes, the stock setting should be fine. I have mine set on 5. I am 195 and the wife is 130.
 

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Nobody Home
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1,768 Posts
if you only adjust the rear spring preload, you have only affected loaded preload, not raised the rear of the bike.
Sit on your bike with the shock on minimum preload. Have a friend measure from the ground to the license plate (for example). Adjust the shock preload to maximum and measure again. The back of the bike will be sitting higher. Ride height is where the bike sits in it's suspension travel. The only time more preload won't increase the ride height is if the fork or shock is topped out.

If you weigh more than Kawasaki's "average" rider you want more preload, less if you weigh less. The idea is to adjust the preload so the bike's ride height is the same so the suspension can work properly. A balance between topping and bottoming.
 

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Workin' to ride
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559 Posts
The factory setting for the rear shock is number 4 (max is 7). If your passenger does not complain about bottoming, or really harsh 'butt jolt' when hitting pot holes, the stock setting should be fine. I have mine set on 5. I am 195 and the wife is 130.
Thanks Bryan...exactly what I was looking for.

Steve
 

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Workin' to ride
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559 Posts
I'm being lazy, because I think my owner's manual is down in the garage, but is the procedure for adjusting rear shock preload in the owner's manual? Is there a special tool?
 

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Crazy Old Guy
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1,189 Posts
. . . . The only time more preload won't increase the ride height is if the fork or shock is topped out.

If you weigh more than Kawasaki's "average" rider you want more preload, less if you weigh less. The idea is to adjust the preload so the bike's ride height is the same so the suspension can work properly. A balance between topping and bottoming.
I concur! :biggrin:
 
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