MUST DO suspension adjustment/mods

[Hellgate]

hmmm... so 100-150 extra for adjustability, and bigger calipers (the R6 ones ARE bigger right ?)

The R6 calipers are the same at the '07 and up calipers. You will need shims for the calipers, the fender and you will need an R6 axle and nut. If you go to the "other" place there is a very good sticky on the specifics of the converstion.

 

[schumy]

The R6 calipers are the same at the '07 and up calipers. You will need shims for the calipers, the fender and you will need an R6 axle and nut. If you go to the "other" place there is a very good sticky on the specifics of the converstion.

yeah, i read up on it.... i asked in another thread here, about those shims that seem to not be made anymore.... why are THOSE SPECIFIC shims the only ones available (or should i say WERE available). Why can't i go to my local hardware shop and get some washers... or go to a machinist who can make some on spec for me?

 

[FZ1inNH]

So I weigh about 225. Do you guys recommend I set the back suspension to the max value, as others have mentioned? Also, can someone post a quick how-to for adjusting it? I know I could search, but it may be nice to have the info in this thread since it's about suspensions (so other noobs like me find it easily in one place). edit: I did a search, couldn't find a "how-to" for doing this. I know, RTFM! )

Scott, I weigh about the same. 7 suits me just fine. While I'd like to have some more adjustability, I can't part with that much money for an Ohlins. 7 will do wonders for you! There is a spanner wrench in the kit under the seat and a handle to slide over it. Put the wrench into the slot on the left (clutch side) of the bike that is at the top of the rear shock, just in front of the side cover. Then, hook the wrench into the holes you see and pull hard. I can't remember which way to turn to go to 7.

And maybe I should just take it to the shop and have them flush/refill the oil in the front with a heavier weight?)

You can or go buy a cheap hand pump and do it yourself. The best method is to drop the forks and turn them upside down and pump all the oil out. Measure it and put back in what came out with the heavier oil.

edit: Also remembered, the guy at the shop said my bike has some really good aftermarket "racing" tires on it. I can post the details once I get home if necessary, but is this a good or bad thing for me as a new rider?)

Did you buy the bike new or used? Curious....

(sorry for all the questions, but you guys are awesome)

Thanks Scott! We try to be helpful! :thumbup:

 

[Hellgate]

yeah, i read up on it.... i asked in another thread here, about those shims that seem to not be made anymore.... why are THOSE SPECIFIC shims the only ones available (or should i say WERE available). Why can't i go to my local hardware shop and get some washers... or go to a machinist who can make some on spec for me?

That's my plan, shim with what I can find/make. Can't be too hard, right???

 

[Scott]

Did you buy the bike new or used? Curious....

The problem I have is that I'm new to riding, so I don't know how things should feel, and it's a used bike, so I'm not sure if everything is stock (springs, oil weight, etc).

Thanks for the answers! Except... should I just guess on which way to turn it? lol

 

[schumy]

That's my plan, shim with what I can find/make. Can't be too hard, right???

only thing i can see going wrong with "what i can find" is a fraction of a mm at high speed could technically make a big difference. BUT, a good machinist can surely put out 10-20 of those lil suckers that are within 0.001mm or not (maybe 0.01mm is enough) hehehe

 

[schumy]

Remember you need to consider the "sag" of the bike too. Sag is the difference in the height of the bike without the rider vs. the height with the rider. Totally off the top of my head, you want about 25mm to 35mm of sag. Not enough and your suspension will not conform to the bumps and will bounce off of them. Too little and your bike will be sloppy. Also your riding preferences need to be taken into consideration too. Suspension set up is both an art and a science.

Where do you measure the height with and without the rider.

Tire pressure has a big influence on handleing too. Too much and the tires will hop more and not warm up all the way, too little and the tires may over heat. The rule of thumb, is measure the pressure of stone cold tires, ride them for about four to five laps, measure them again and the pressure should only change 2 lbs, or so. That's the art part of it, but it works, 95% of the time.

i thought it was 30% more pressure after they are warmed up. i read this in some thread here.

 

[Nelly]

Great post mate,
I think your also being modest, to be in the advanced group you aint no slouch. Fair play to you.

Nelly

 

[schumy]

Great post mate,
I think your also being modest, to be in the advanced group you aint no slouch. Fair play to you.

Nelly

naw... i'm really not being modest. I have A LOT of stuff to work on before i can even say i'm decent. I'm an OK rider, and i have ballz of steel.

I still have to work on my braking, and race line. But the braking should be solved somewhat when i fit the bike with new springs, and the racing line... well that's gonna take some more track days

 

[Hellgate]

Where do you measure the height with and without the rider.



i thought it was 30% more pressure after they are warmed up. i read this in some thread here.

As long as you measure from the SAME moving point you are fine. Like the bottom of you rear fender and the bottom of your fairing, or front and rear turn signals. You'll need a friend or two to help.

 

[Avalon786]

So who here put the heavier oil in the front suspension? Does it make a big difference? When i go in the twisties for some reason i have a hard time going down them as fast as going up them, it feels like the bike wont corner as well, the suspesion really dives down. Dunno if its just the way it is (harder going down because of more weight)? So you guys put 15w in the forks?

 

[gt89stang393]

The loose I feel is like when your in a rear wheel drive vehicle in the rain and the tires slip a little bit and you fishtail a little, the tires are planted, I don't need to accelerate very hard, but I will say if I do I don't seem to feel the issue as much. Its hard to explain, this is the best example I could give.

 

[schumy]

The loose I feel is like when your in a rear wheel drive vehicle in the rain and the tires slip a little bit and you fishtail a little, the tires are planted, I don't need to accelerate very hard, but I will say if I do I don't seem to feel the issue as much. Its hard to explain, this is the best example I could give.

it happens to me sometimes when i make 90degree turns, at the exit the bike slides the back from acceleration, but that's mostly because of dust patches, oil slicks on the road, and other general CRAP. The sensation i got with my bike on the track and the reason for my suspension adjustment was an up and down wavy motion on the vertical axis on the bike.

 

[schumy]

and to give you guys a little teaser of what i was doing on the track, here's a picture that was taken halfway through the day

yes i know, my position wasn't very good in that turn ... but it quickly got better hehehe. And in case you're wondering, that's a zx-6r i had just passed.

 

[Doorag]

Here's what Wikipedia has to say.

Pre-load adjustment
Motorcycle suspensions are designed so that the springs are always under compression, even when fully extended. Pre-load is used to adjust the initial position of the suspension with the weight of the motorcycle and rider acting on it. Both the front forks and the rear shock or shocks can be adjusted for pre-load on most modern motorcycles.

The difference between the fully extended length of the suspension and the length compressed by the weight of the motorcycle and rider is called "total sag". Total sag is set to optimize the initial position of the suspension to avoid "bottoming out" or "topping out" under normal riding conditions. "Bottoming out" occurs when the suspension is compressed to the point where it mechanically cannot compress any more. "Topping out" occurs when the suspension extends fully and cannot mechanically extend any more. Increasing pre-load increases the initial force on the spring thereby reducing total sag. Decreasing pre-load decreases initial the force in the spring thereby increasing total sag.

Since the weight of the motorcycle and rider are the only forces compressing the suspension from the fully extended position, preload doesn't change the forces on the springs under riding conditions. Changing the pre-load does not change the way the suspension reacts to bumps or dips in the road surface either. Two simple examples using the motorcycle's forks shows why:

Suppose that the bike and rider put a total weight on the front suspension of 300 lb. Suppose the spring rate of each fork spring is 50 lb per inch. Installing a 1 inch long spacer in each fork leg gives a pre-load of 50 lb per spring, a total of 100 lb. When the weight of the rider and motorcycle are loaded onto the suspension it will compress 2 inch from full extension (2 inches total sag). Now the force exerted on (and by) each fork spring is 150 lb (1 inch pre-load + 2 inch total sag = 3 inch total spring compression) for a total of 300 lb, balancing the weight of the bike and rider.
Suppose we now install a 2 inch long spacer in each fork leg. The pre-load is now 100 lb per spring, a total of 200 lb. The total sag will change since we still have the same 300 lb loading the forks. The total sag will now be 1 inch. The total force on each spring is the same as before, 150 lb on each fork spring for a total of 300 lb force. The front suspension's initial position is 1 inch longer than in the preceding example (1 inch less total sag).
Since the forces are the same in both examples the reaction of the suspension to bumps and dips in the road will be the same. The difference is that there is less chance of topping out in example 1, less chance of bottoming out in example 2. Motorcycle manufacturers generally provide optimal total sag settings.

This is also why too-soft springs cannot be "fixed" by adding pre-load, too-stiff springs cannot be "fixed" by reducing pre-load. Changing to springs of the correct spring constant for the total weight of the bike and rider is the only solution.

Some motorcycles have externally accessible pre-load adjustments. Typically, this is a screw-type adjustment that moves a backing plate inside the fork against the top of the fork spring. The farther down the adjuster is screwed, the higher the preload.

A few motorcycles allow adjustment of pre-load by changing the air pressure inside the forks. Valves at the top of the forks allow air to be added or released from the fork. More air pressure gives more preload, and vice versa.

Pre-load on bikes without adjusters can be changed by disassembling the fork and changing the length of the spacer between the top of the fork spring and the fork cap. Spacers can be installed under the rear shock springs similarly. A longer spacer gives higher preload, and vice-versa.

The pre-load on both forks should always be the same. Dangerous handling characteristics and possible mechanical damage can result otherwise.

 

[DefyInertia]

FWIW, for track work I switched between 4 and 5 a lot and finally settled on 4. I was getting between 30 and 35mm of sag.

schumy, I can't see that picture. Post some more or post a link if you get a chance.

scott, post brand/model/size and we'll tell you about your tires. Also, there are numbers on the rear shock...1 through 7. Adjustments are easiest to make while the bike is on the centerstand.

 

[sideslider]

I have my rear set to (7 i think) second from the highest... and a new set of dunlop qualifiers

bikes does great at most all speeds I ride with the exception of the front end which is squishy. I like the idea of switching the front springs and oil but I'm not sure that I want to mess with the sag and all of the technical stuff.

So can anyone refer me to a suspension place around portland OREGON?
(I should probabally search this ...im sure it has been brought up before)

 

[schumy]

schumy, I can't see that picture. Post some more or post a link if you get a chance.

alright... should be better now

How much do you weigh DI ? 4 seems a little low, well 3 was bad for me so i don't think 4 would be much better. I didn't have the luxury of lapping a few times with different settings. I'll try and get a yamaha toolkit somehow and go to a track day and try different settings.

 

[Hellgate]

and to give you guys a little teaser of what i was doing on the track, here's a picture that was taken halfway through the day

yes i know, my position wasn't very good in that turn ... but it quickly got better hehehe. And in case you're wondering, that's a zx-6r i had just passed.

Lookin' very good brother! I think your position looks fine. Head pretty much lined up with your hips, looking through the turn, and you look comfortable and sure on the FZ. :thumbup:

As others have said if you're in the advanced group you ain't no slouch!

Get your suspension dialed in a bit more and you'll be spanking the field!

When I was roading I loved having a smaller bike because I could brake SO much later than the big bikes. I'd cut in front of them going into the corners and use blocking moves at the exit and then out brake them into the next corner. If it was a set of essess or a chicane they couldn't pass me until the next long straight. The other good thing about a small bike is I could start my drive out of the apex sooner and carry more speed to the exit of the corner and get a few bike lengths on them. Sometimes they'd pass me but then I'd out brake them again. It was fun! My buddy had a Honda Hurricane and we'd go back and forth. His bike was much faster, but my was lighter and I had a bit more skill than him. We'd finish a race and laugh and laugh about how we diced back and forth.

There was dude called "Rat", Jim Sonnlighter. Rat was about 6'4" and he shoe-horned himself into an old TZ250 with 80hp, knees sticking out like wings. He had been racing for about 30 years and was soooooo smooth. I'd just follow him to understand his lines. After a couple of years I could finally pass Rat and we would dice. He was so cool he'd explain to me how to beat him the next time we went out. I learned from him that HP doesn't really matter.

I didn't really care where I finished as long as I had a good dice.

 

[Hellgate]

alright... should be better now

How much do you weigh DI ? 4 seems a little low, well 3 was bad for me so i don't think 4 would be much better. I didn't have the luxury of lapping a few times with different settings. I'll try and get a yamaha toolkit somehow and go to a track day and try different settings.

Once I put in my RT springs I bumped the stock shock up to 5 and was much happier. 3 was good for the stock springs. I weigh 175.