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View Full Version : Adjusting rear suspension preload



Frodo
07-24-2007, 04:24 AM
How do you guys do it? The C shaped connection fits on the knurled adjuster well, but when I apply pressure using the ring spanner it slips. Really interesting with a hot exhaust! I'm looking at welding a handle permanently to the C-connector.

Other suggestions?

g-man
07-24-2007, 05:16 AM
You just have to make sure it is correctly seated in the grooves before turning. It can twist when you put pressure on it and jump out the groves. I found also the more preload is on the the bike the harder it is to turn the adjuster.

Frodo
07-28-2007, 07:13 PM
The main problem with the supplied C-spanner is the middle tang. This creates a fulcrum which levers off the end tangs. I cut this off and welded the C-spanner to the ring spanner.
http://i84.photobucket.com/albums/k37/Frodo014/IMG_5495.jpg

Cheers

PetrolHead
07-29-2007, 02:25 PM
Sorry if it tells you this in the manual, but what range of setting is their e.g. on what scale is the range of adjustment and what are the benefits???

Frodo
07-30-2007, 03:05 AM
Changing the preload (and dampening) makes a huge difference when carrying a passenger or serious load. With the standard setting of 2 or 3 notches from minimum, the suspension will sit down real low, make the headlight aim for the sky, and the suspension will bottom over bumps with a pillion. Increasing the preload to the maximum will stop this happening. You will also need to increase the dampening (screw at the bottom of the shock) by turning it in (clockwise) half a turn (5 clicks), otherwise the rear end will pogo.

The difference is more subtle even with one person on board. You might like it softer for cruising or commuting, but tighten it up through the twisties.

Just remember to adjust the dampening as well..

I adjust my suspension regularly. On the F650, this was a simple remote dial. On the Pegaso, it was a real pain (literally). Hence, making up the tool. Now it is just about curse-free!

Cheers

DonFanatico
07-30-2007, 06:29 AM
Hang on hang on Frodo...run that by me again please :confused:


I have never done this before...if you have pix to show what and where to turn that would be great (am not really technical)

So the standard setting is too soft normally? I am a a big lad (100KG) , would the standard setting be too soft for me? I would prefer a tighter setting for the twisties etc. what do I need to turn and how much? What about the front?

Anything that can go wrong?

Thanks

MilesB
07-30-2007, 06:34 AM
What about the front?
You can't do anything about the front suspension - it's fixed.

Miles

MilesB
07-30-2007, 06:38 AM
Changing the preload (and dampening) makes a huge difference when carrying a passenger or serious load. With the standard setting of 2 or 3 notches from minimum, the suspension will sit down real low, make the headlight aim for the sky, and the suspension will bottom over bumps with a pillion. Increasing the preload to the maximum will stop this happening. You will also need to increase the dampening (screw at the bottom of the shock) by turning it in (clockwise) half a turn (5 clicks), otherwise the rear end will pogo.

The difference is more subtle even with one person on board. You might like it softer for cruising or commuting, but tighten it up through the twisties.

Just remember to adjust the dampening as well...
Thanks Frodo

Really usefull to have some input from someone who knows what they are doing when it comes to tweaking suspension settings.

At the moment I find that the stock settings are pretty good - this is one of the best handling bikes I've ever ridden (and my last bike was a Ducati - they're good too). However it looks like my Strada is going to become an occasional touring machine (2up + luggage) so its good to get some guidance.

Miles

g-man
07-30-2007, 08:32 AM
There are suspention settings in the handbook. But here's my humble take on it.

For a solo rider i found the std setting too soft. (i'm 74kg). When banked right over and powering through a flat out 4th gear sweeper for example, it would wobble and weave at the rear. This is when the std pegs would deck out hard.

All bikes (and cars) have to have sag. If you lift the back of the bike up then let it down the rear will drop a bit. That is static sag. Then it will go down a bit more when you sit on it. If you put more preload on then it will take more weight for the bike to sag, also it will affect the geometry of the bike and makes it sit higher at the rear. This makes it turn quicker and it's easier to drop into corners.

The shock isn't adjustable for bound and rebound, it's just a general harder/softer overall adjustment. I have mine 3 clicks from fully hard setting. This stops the weaving/speed wobbles etc as it slows down the rate at which the shock can bounce up and down.

But the preload will need to be set different for a skinny guy, big guy, loads of luggage, pillion etc. Mine is on 3 clicks now. Any harder and the spring is pushing the shock right to the top of its travel leaving no static sag (topped out) and it hardly even went down when i got on it. I had this problem on a Caterham i raced last season. Under braking the rear would top out leaving no suspention travel.... the result was under hard braking if there was ever a tiny bump in the track the rear would be all over the place and worst case would lock up. This is how i've kinda learned a wee bit about the basics off getting a decent set up and the difference it can make.


The reason for having sag is to get the suspention working in the middle of it's range so when you go over a dip for example the suspention extends to compensate. I think yours will be set too soft for your weight so the bike is sitting ass down making it harder to turn, and only using half the travel it's meant to.

The best think i've found is the play with it and try things and learn that way. Rump the shock up and put a few clicks of preload on it and go a run, you'll feel it instantly, then if it's too much move it about a bit more till you like it. There's too many guys out there who read in mags and on the net about the latest super duper settings. But what works for one guy will be crap for the next. It's all about feel and personal tastes and riding styles.

Jees... i'm away for a lie down after all that :bump:

DonFanatico
07-30-2007, 10:22 AM
:worship:
There are suspention settings in the handbook. But here's my humble take on it.

For a solo rider i found the std setting too soft. (i'm 74kg). When banked right over and powering through a flat out 4th gear sweeper for example, it would wobble and weave at the rear. This is when the std pegs would deck out hard.

All bikes (and cars) have to have sag. If you lift the back of the bike up then let it down the rear will drop a bit. That is static sag. Then it will go down a bit more when you sit on it. If you put more preload on then it will take more weight for the bike to sag, also it will affect the geometry of the bike and makes it sit higher at the rear. This makes it turn quicker and it's easier to drop into corners.

The shock isn't adjustable for bound and rebound, it's just a general harder/softer overall adjustment. I have mine 3 clicks from fully hard setting. This stops the weaving/speed wobbles etc as it slows down the rate at which the shock can bounce up and down.

But the preload will need to be set different for a skinny guy, big guy, loads of luggage, pillion etc. Mine is on 3 clicks now. Any harder and the spring is pushing the shock right to the top of its travel leaving no static sag (topped out) and it hardly even went down when i got on it. I had this problem on a Caterham i raced last season. Under braking the rear would top out leaving no suspention travel.... the result was under hard braking if there was ever a tiny bump in the road the rear would be all over the place and worst case would lock up. This is how i've kinda learned a wee bit about the basics off getting a decent set up and the difference it can make.


The reason for having sag is to get the suspention working in the middle of it's range so when you go over a dip for example the suspention extends to compensate. I think yours will be set too soft for your weight so the bike is sitting ass down making it harder to turn, and only using half the travel it's meant to.

The best think i've found is the play with it and try things and learn that way. Rump the shock up and put a few clicks of preload on it and go a run, you'll feel it instantly, then if it's too much move it about a bit more till you like it. There's too many guys out there who read in mags and on the net about the latest super duper settings. But what works for one guy will be crap for the next. It's all about feel and personal tastes and riding styles.

Jees... i'm away for a lie down after all that :bump:

gman, fabulous thank you. so essentially there is one screw to turn to adjust preload only. this will adjust how far the bike sits down when sat on it...for heavier peeps has to be more clicks to the right than for skinnier folks.


:worship:

g-man
07-30-2007, 11:28 AM
It's not a screw for preload. The flat screw at the bottom of the shock is to adjust the damping. Go to the right hand side of the bike and you will see it all from there. Look at the top of the spring and you will see a big knurled nut with notches in it. Your will prob be set on the lowest or 2nd lowest. It's this big knurled nut that you turn to tighten'loosen the prelaod. You need to use the tool that comes in the tool kit. I'm sure Frodo had problem with it slipping off so he welded the spanner to it as you see in the above posts.

I would go out and take photos, but i'm heading out now.......... and you guys know how much i like my photo threads :happy:

PetrolHead
07-31-2007, 02:46 PM
Right then, had a look at my rear suspension today, was amazed to see that it was set on zero pre-load, which from the above is clearly not the correct setting considering I'm 6'4" weigh nearly 90Kg and have a top-box fitted to the back of the bike with probably around 8Kg of laptop and documents in tow, hanging right at the back of the bike.

Got the spanners out and have initially changed it to a setting of "4" clicks from minimum "0", for ease of referencing I've taken a photo and added some reference numbers. Was easier to adjust than I expected... Will see what this feels like tomorrow.

Havent adjusted the Damper, photo also below to show what mine is set to.

Using the scale below, I've three questions... 1) Some posts on here advise that there is a standard factory setting, what position was this?? 2) What setting do you have on your bike? 3) Should I adjust the damper, if so, to what??

Cheers, Steve.

g-man
07-31-2007, 04:36 PM
Yep, thats the preload adjuster and mine is set to 3 on your scale. But my bike is a Strada, dont know if there's any difference regarding the rear suspention. I think the Trail might have slightly more travel and be a bit softer overall.


So to answer you questions...
1/ It's in the handbook, cant remember what page.
2/ 3 notches of preload and shock 3 clicks BACK from full hard.
3/ Yes, adjust it to what you feel is right.

As i posted before, adjust it and try it and see what you think. Then adjust it and try it again. if you've upped the preload, click up the shock a 4-5 clicks too to stop it pogo'ing about. If you get it wrong and dont like it, get the handbook out and reset it all to standard settings then stard again. :cheers:

PetrolHead
08-03-2007, 03:12 PM
Thanks for the tips gman & all, can't believe how different the bike feels like, havent ridden it hard or anything, difficult to explain, but on my basic commute the handling felt much more precise with greater confidence in the corners and it doesnt "rock" as much when accelerating hard. Havent adjusted the damper, may leave it as it is for a while to get a better benchmark for how it feels and then make a few adjustments.

Without this forum I'd of probably been riding the bike like that for months not realising what difference could be made :worship: :cheers:

Frodo
08-04-2007, 03:31 PM
Hey PH

Is that corrosion I see around your suspension linkages? Do have salt on your roads? Have you tried any corrosion inhibitor, such as the Scottoiler product?

PetrolHead
08-04-2007, 04:17 PM
Funny you mention that, as it isnt really visible on the bike, but I did notice it myself on the photo above at such close range image...

Chain is lubed OK so no need for scott oiler as I dont do enough mileage to justify it, just need to keep an eye on the other bits.

joe bar
08-04-2007, 05:42 PM
Hey PH

Is that corrosion I see around your suspension linkages? Do have salt on your roads? Have you tried any corrosion inhibitor, such as the Scottoiler product?




...........Chain is lubed OK so no need for scott oiler as I dont do enough mileage to justify it, just need to keep an eye on the other bits.

Think there's a bit of crossed lineage here. Frodo was not referrring to Scottoilers auto chain lube. Scottoiler also make a corrosion inhibitor FS365, costs around 6 a litre. Good stuff and lasts ages, just spray on after you've washed the bike and helps neutralise salt and corrosion. I always give an extra squirt around the wiring as well, helps keeps the connectors clean.

PetrolHead
08-05-2007, 07:44 AM
cheers for clarifying, will get it sorted later today... that is after I've sorted the bees nest I've found in the garden.

Frodo
08-07-2007, 06:04 PM
Joe

Is there any place you don't spray the FS365 (other than brakes)? Any problems with using lots of it?

Thanks

joe bar
08-07-2007, 06:10 PM
Joe

Is there any place you don't spray the FS365 (other than brakes)? Any problems with using lots of it?

Thanks

I tend to spray anything that's metal (obviously not the brakes) and the electrics. I stay away from bodywork and the instruments.

In winter I at least try and hose the bike off to wash away the salt and then spray the bike with the FS365, in some ways it's better done wet as it "creeps" easier that way.

MilesB
08-08-2007, 03:21 AM
I tend to spray anything that's metal (obviously not the brakes) and the electrics. I stay away from bodywork and the instruments.

In winter I at least try and hose the bike off to wash away the salt and then spray the bike with the FS365, in some ways it's better done wet as it "creeps" easier that way.
I use FS365 on my Honda scooter - spray everything: wheels, engine, exhaust, bodywork - all OK and still looking good. Accidentally sprayed the front brake disk - not so good!

Miles

mouse
05-14-2009, 01:16 PM
Ok - resurrecting an old post here!

Trying to adjust my suspension after adding luggage and about to starting taking passengers now I have a spare lid. Only problem is I don't have a C-connector so can't adjust the pre-load.

Anyone got any good sources for them or alternative tools?

Cupid Stunt
05-14-2009, 06:04 PM
Order one from your Aprilia dealer
For now, just jack the bike up so the rear wheel is off the floor and try twisting it with your hands or wrap a leather belt around it and use that

mouse
05-15-2009, 07:55 AM
cheers cupid :)

Paul B
05-16-2009, 03:44 AM
I was messing with my rear suspension yesterday as I'd left it set for riding with full luggage (No.4 using PH pic), No.3 has the bike well balanced for me when riding with or without a loaded top-box. Never adjusted the Rebound dampening before, but on checking it was over damped so it was backed off two clicks.

Shame the front forks have no adjustment as the compression & rebound dampening aren't sufficient, it'd require about 2 clicks adding to each to stop the little bit of a bounce it has. Any body know what weight the fork oil is?

Frodo
05-16-2009, 05:34 AM
Front fork oil is 10W. You could increase viscosity and/or increase the length of the preload spacer. I chose to stick with standard when I last changed the fork oil. I have a change coming up soon at 40,000km and will leave it the same. IMHO the forks are much better than on my F650.

Cheers

Paul B
05-16-2009, 04:44 PM
Cheers Frodo, I'm only a light weight (about 70kg kitted out), so the weight of the front and rear springs are about spot on. I'll try a 50:50 mix of 10W & 15W, as IMO, the front on mine just needs slowing down a fraction.

mouse
05-16-2009, 05:18 PM
Paul B what's your rebound damping set to? Mines on 6 clicks at the moment which may be too much. :)

Paul B
05-17-2009, 02:38 AM
Hi Mouse, just popped down to the bike to see ... from being fully in, its set to (backed off) 15 clicks.

Take the bike off its side stand and sharply push down with one of your feet on the rear pillion foot-peg, as you release the load off your foot and bring it back up to the starting position, the rising rate of the rear sus' needs to match your foot. Too much dampening and the bike is slow to rise, too little and it will push your foot back up.

As we all weigh different amounts, the amount of force we exert on the shock is different. I find this a quick way of getting a good base setting to work from.

Mammad
05-17-2009, 08:43 AM
Front fork oil is 10W. You could increase viscosity and/or increase the length of the preload spacer.

I think the front fork oil is 5w. I have changed mine twice so far and been using 7.5w oil. The front is much stiffer now and braking is more comfortable cause of the less fork travel.

Anyway, fork oil viscosities are a bit messed up and differ from one manufacturer to another, as you can see in this .pdf link.

http://www.motul.com.au/product_line_up/fork_brake_others/images/PDF/FORKOIL_EXPERT_BLEND_CHART.pdf

Regarding suspension set up, both front and rear, I think that there are a few basics that apply in most cases. You can find such articles and reports online. The front suspension is less frustrating bearing in mind that it's not adjustable. Changing the fork oil and messing with the spring spacer can make the front sportier but too much is not good. If you use heavier oil than the manufacturer the fork will not behave ideally because the rebound will be slower and will not match the compression. This means that when u hit a bump the fork will take longer to expand and lose (proper) traction for more time. That cannot be solved in our case without a rebound damping setting.

Something that is very important about the rear suspension is that the preload and rebound settings depend on each other for the same reason as the front suspension. Setting the rebound is in no way a personal matter and is connected with the preload setting to match the compression and de-compression speed. As you know sportbikes also have settings for compression and rebound rate, apart from preload and dampening.

Setting the rear preload is not a big deal and can be done by measuring the static and dynamic sag. Static sag is the (little) rear suspension travel from it's full length when the bike sits on it's own, with no extra weight (driver, passenger etc..). The dynamic sag is the suspension travel with a person on the bike. Measuring the suspension 'dive' (dynamic sag) is a good way to start looking for a good preload setting. This can be done by measuring the distance the rear of the bike dives from a fixed point in the swingarm (could be the axle nut) to a point in the rear of the bike (let's say a spot or a bolt on the exhaust). In sportbikes for example the dynamic sag should vary between 2.5 to 3.5 cm. In a bike like the Peg the d.sag can be a little more (around 3 to 4.5 cm) because of the longer suspension travel and softness compared to an sbk. After that u need to adjust the rebound which is a little trickier and needs experience and testing. I think it is better to do that in a twisty road while turning hard, to check whether the rear of the bike does or does not lose traction when working (de-compressing) under pressure. If the rear tends to oversteer (spin) or loses stability in a turn then u should go for quicker rebound and tighten the screw a click more and so on..

mouse
05-17-2009, 08:55 AM
Cheers Mammad. Good description of it there. I reckon I need to add 1 to the preload on mine but haven't got the C piece yet. I've played around with the damping again today (thanks to Pauls quick test advice) but it's wet so won't get to test it until the weather dries up. Set to pre 3 and damp 10 clicks (anticlockwise from fully tight). Seams to feel OK now but as I say won't know until I get to take it for a spin :)

Mammad
05-17-2009, 09:27 AM
Just for the record, I've set mine to 1 click back from the hardest setting for preload and 2 or 3 clicks back from fully tight for rebound. It seems very tight but its ok considering I'm over 100kg and also have friends that weigh even more..
I have also done 39000km so the shock has gone softer over time. I have tested and proved these settings for sport riding in a long ride in every kind of tarmac in the mountains of Greece this Easter. I went along with 2 Gsr 600, a BMWr1200GS and a KTM 990 Advntr. I was faster than the BMW and one of the GSRs in most cases.. The Peg is a good bike after all..

Fliptoplid
05-17-2009, 09:49 AM
Some great info here thx guys . . . I have just adjusted my rear end (no inuendo intended) 4x clicks harderd to notch 6 and the damper 5x clicks+. Also, after chatting with my local dealer, I have experimented with the height of the front forks extending them up to the max.

The effect (with me at 6' and 90k + pillion) has been dramatic - a much, much better ride. No bottoming, no wobbling, no pillion slipping forward and tight and tidy on corners. I was beginning to have doubts and thinking I should have stuck with my old Peg Cube - now I'm in love all over again :)

PS. I found using a socket and ratchet on the 'C' spanner prevented the slippage problems without the need to weld :)

Fliptop