Rear preload adjustment for a heavier rider.

[ronsaw]

Posing a question for those with experience adjusting the rear spring preload from stock. Quick background: I am 300 pounds, ride alone, with no bags/cases. I do like to ride on curvy or sweeping roads much of the time, and while I do not set a blistering pace, I have enough experience and confidence falling in at the rear of a pack of canyon carving sport bikes to usually stay with them, if I like. I have had my 2013 NC for a year and made no adjustment on the preload - anyone have an idea about how much to crank her down for an initial adjustment from stock? I have had a GPZ and Ninja in the past, so am aware of how the characteristics of the bike may change. Just looking for info.

Thanks in advance, ride safe.

 

[Garnet]

Start by measuring your bikes max suspension travel with no load. Put the bike on the center stand and measure from the rear axle up to a spot on the fender or hand rails. Then sit on the bike and bounce the bike up and down and let the suspension settle. Get a friend to measure the same spot, (try to have your feet up, helmet and jacket on). The difference between the two measurements is called sag.

You then adjust your shock preload so that your sag with rider is about 1/3 of wheel travel. I think the NCX has about 5.9" of wheel travel, so you want to crank the shock down till you have around 2" of sag when you sit on the bike. The stock spring is a bit soft so you may not be able to hit those numbers.

This is a quick how to. There is much more to be read on the subject including how to estimate how much stronger spring you may need on the net. Just google "measuring suspension sag on a motorcycle"

 

[Hati]

Beaten to the punch...

 

[ronsaw]

Thanks, much appreciated!

 

[Garnet]

One more tip: Put a mark on the threaded nut that preloads the spring. That way you can tell how many turns you have moved it.

 

[DirtFlier]

+1 on marking the adjuster ring. You can also measure the spring's installed height so you'll know what you've done.

 

[Deleted member 1183]

Given your weight I believe You will need to ramp up the preload considerably. Another reason for this is that the spring on the NC shock sags quite a bit from new. Mine did and I weigh 175lbs. Regrettably the lock rings are not easy to access. While I have nothing against the scientific methods of measuring adjustment as described above, I tend to work on a seat of the pants adjustment method. As soon as it feels right I stop adjusting. I also like to have my bikes with as little sag as I can get away with on the rear shock, as the roads I ride are usually very rough.

I will eventually replace the shock on this bike as I intend to have it for a very long time. I do not believe the bike warrants hugely expensive suspension components but I would like to have damping adjustment and if not too expensive, remote spring preload. Part of my reason for this is a bad lower back, and the aforementioned rough roads, but also a high rear end helps the bike to steer quicker on really twisty roads. Please let us know how you get on when you have completed your adjustments, and the difference it makes to the handling of the bike.

 

[Joao]

As Grift sad, I truly believe you might have to increase the preload from your rear suspension.

I have already done some measures to my suspension sag following same procedure mentioned previously and with my current weight (184pounds) it is about 1/3 of the suspension maximum travel.

I also consider the stock rear suspension a bit stiff and little reactive to absorb some bumps, and I do not want to worsened my hernia. After some research for possible alternatives, because as Grift I also intend to keep my "whity" for some time, I found that a good choice would be a suspension from Ohlins as it offer dumping adjustment. I have to consider this investment seriously as it would cost almost 600€ for a factory adjusted suspension for my riding weight.

 

[Tim Clynes]

It sounds like it is worth adjusting your suspension, you will mostly ride one up without luggage, so it makes sense to set the bike up that way.

 

[belrix]

I'm also a heavier rider and like to ride on gravel roads. Will adjusting the rear preload help deal with a washboarded surface?

Thanks

belrix

 

[Garnet]

I'm also a heavier rider and like to ride on gravel roads. Will adjusting the rear preload help deal with a washboarded surface?

Setting the preload will help reduce the tendency of the suspension to bottom out. Washboard surfaces are hard for shocks and forks to deal with. The rapid movement up and down cause the damper rod forks to lock up and our budget shock's fluid will begin to froth. Better quality components, with shim stack type valving that allow the high pressure fluid pulses to bypass, are needed.

Lowering tire pressures will help off the pavement. Just make sure you have a tire pump with you, or take it very easy till you find an air hose once your back on the tarmac.

 

[belrix]

Thanks for the info. I'll adjust the preload for now and look at upgrading the forks and rear shock later.

bw