Preload?

[hypo]

For those of you already riding the FZ8... did you mess with the rear suspension AT ALL? what did it come from the factory with? middle of the preload or all the way to one or the other?

I am reading how people aren't happy with not being able to really tweak it the way they want to, but since my riding is probably only 20% twisties I'm not so sure I'm really concerned with that as long as it can handle my 185lbs I'm happy.

anyone ?

 

[mano1192]

not a concern for me as of yet. I know the front forks arent adjustable, I thought the rear was??

 

[GarryM]

Hi guys, coming from a 2006 model R6 I found the FZ8 rear suspension to be very lacking in rebound damping. The front forks seemed OK, maybe not quite as good as the R6 but up to the job.

After encountering a particularly bad bump a few weeks ago that almost bounced me off into the bushes I decided to replace the rear shock with a new stock shock from the US market FZ1 (with the black spring) from Xtreme Powersports.

I weigh 75kg (around 150lbs I think) and the damping and spring weight seem perfect for me and also match the front forks well using the factory recomended FZ1 spring preload and rebound adjustment settings. It bolts straight in re-using both of the FZ8 bushes. I'm very happy with the result. The ride is fractionally firmer (but not harsh by any means) but more controlled with much more feedback from the rear. It feels more planted to the road now as well, helping me get onto the power much ealier and harder in the corners. Considering the price was less than 1/2 of what an Ohlins shock would have cost me I think the result was excellent.

 

[Hereward]

I weigh 100kg found the rear a little soft on some of the UK's more bumpy roads, tried the preload at 7 and was a little harsh, knocked it down to 6 and it's fine, might go back to 7 in the future as rear felt a little more planted.

 

[hypo]

Thanks! I'll definitely be looking into that. Good lead on the replacement shock!

 

[millarjk]

rear spring setting

I weigh 250lbs any ideas what i should set it at and is there a rule of thumb,new rider

 

[Hereward]

set it at 8 get used to it then move it to 9. I eventualy settled on 7 which seems to work fine for my weight.

 

[Ivy33]

So how does the arcane art of setting preload actually work? Does it say what to set it at in the manual? I'm at work so I can't check it right now.

I weigh 190 with my gear when riding. How do I know what to set it at? Is it kind of a hit/miss endeavor? Now that I've ridden the bike for a while it seems a little stiff to me so do I set it down a notch and try it there?

Sorry if I sound like a noob (I am) but I'm not sure exactly how it works.

 

[SpunkyTheTuna]

So how does the arcane art of setting preload actually work? Does it say what to set it at in the manual? I'm at work so I can't check it right now.

I weigh 190 with my gear when riding. How do I know what to set it at? Is it kind of a hit/miss endeavor? Now that I've ridden the bike for a while it seems a little stiff to me so do I set it down a notch and try it there?

Sorry if I sound like a noob (I am) but I'm not sure exactly how it works.

Preload basically compensates for your weight. It does more, but for simplicities' sake lets leave it at that for now. I don't recall at the moment the suspension travel on the rear shock of the FZ8, but suppose it's 5 inches. That's an arbitrary number; the real number's in the owners manual someplace. Hold the bike up off the sidestand and measure accurately the distance from some repeatable point on the rear subframe, ideally some point directly over the rear axle. Now, wearing your riding gear, sit on the bike. Have one friend hold the bike upright so you can have all of your weight on the bike and pick up your feet. Have another friend measure from the floor to the exact same point on the frame as above. The difference between the two measurements is the amount of sag. OK, now this part's controversial, since some like more sag and some like less. I tend to want the bike's suspension in the middle of it's travel when i'm on it, so I adjust the preload collar so that the sag is just under half the total suspension travel. If you adjust for less sag, you get a bit stiffer spring pressure initially and if you adjust for more sag you get a bit softer spring pressure initially. That's all the adjusting we get on our bikes' suspension as it comes from the factory.

 

[GarryM]

I thought the generally accepted figure for sag on a road bike was about 30mm (1 1/4"?) plus or minus a little for personal preference. Setting the sag to the middle of the suspension travel is a lot of sag (around 75mm on an FZ8).

Ivy33,

The FZ8 rear end is considered by most to be very softly sprung. At 190lbs you might actually be using all of the suspension travel and riding on the bump stops on big bumps. As strange as this sounds you may in fact get a smoother ride by INCREASING the preload as this will keep you off the bump stops. Try measuring the sag and see how much suspension travel you are actually using. If it's a lot more than 30mm you may need to fit a firmer rear spring if the preload adjustment doesn't give you enough range.

 

[Hereward]

The art of preload LOL It's an arcane thing but Esentialy, the heavier you are then increase the preload.....how much by? simple, personal preferance! if it feels soft and "bouncey" then increase it, if it's too stiff and harsh then decrease it! Ultimatly your looking at the bike traveling equaly on the front and rear suspension when you bounce up and down on it but in reality the weight of the bike is shifting backwards and forewards as you accelerate and decelerate..........set it so it dosn't feel soft and floaty but also dosnt rattle you to death on bumps, some prefare the rear stiffer than others and theres no real set rules for road use just that it's comforuble yet feels planted and giving feedback to you through the suspension via the rear. If in total confusion set it to 9, ride it then bring it down a notch at a time (riding between each adjustment) until it feels "right" I've set it to 7 which feels right for me but I've come from a sports bike which use to skip around at the back under braking on bumpy roads LOL

 

[Hereward]

[ame=http://www.youtube.com/watch?v=mK3flKxf41U&feature=related]YouTube - ‪Motorcycle Suspension - Setting Sag‬‏[/ame]

There you go if you wan't to be spot on.

 

[fzkiwi]

Suspension Mods

I'll be getting my Ohlin's upgrade in mid August as soon as KiwiRider give it back off their long term demo. Replacement rear and springs on front. Will let you know the difference as soon as I've had it done.

Just ordered Oberon Streetfighter mirrors, looking to see if they make pegs and then when funds finally allow I'll be going to Trenditaly to get some carbon!!

 

[djcecil]

i weigh around 185, have had mine on 5 since the day i got it. today after work put it on 6, loved it right away, much better handling. went riding through the twisties and spent half the time at 6, the other at 5 @ 40 miles of riding. 6 seemed much better, but the tire is easy to upset, and it makes me wish for a softer compound. put back to 5 and it feels like you got on a much lesser bike. a 5.5 would be perfect, guess i will need to have to upgrade the rear shock if i want to get the half settings.

 

[Hereward]

i weigh around 185, have had mine on 5 since the day i got it. today after work put it on 6, loved it right away, much better handling. went riding through the twisties and spent half the time at 6, the other at 5 @ 40 miles of riding. 6 seemed much better, but the tire is easy to upset, and it makes me wish for a softer compound. put back to 5 and it feels like you got on a much lesser bike. a 5.5 would be perfect, guess i will need to have to upgrade the rear shock if i want to get the half settings.

Nah, eat more pies you'll be rite' as they say here in Wigan LOL

Leave it at 6 for a few rides, you should be able to feel a little roughness at the back, if it's skiping around when unloaded on the brakes on a rough road thats when it's wrong LOL

 

[djcecil]

i'm a daily rider unless it rains in the morning so it is at 6 unless i go on a pie attack and need to graduate to a 7, but i'm shedding stock parts all month so the bike is losing weight!

 

[Deleted member 438]

I'm 160 lb and I've had mine at 7 almost since the day I got it. It was very wallowy for me from the get go.

 

[Hereward]

Mine too is loseing weight but I unfortunatly am not, ran it at 6 for a couple of weeks then went to seven, I weigh 200 and prefare it a bit stiffer at the rear.........now if this was top gear that could be misconstrude LOL