Emulators and progressive fork springs

AndyW

AndyW

Hero member
Have noticed the mirage front end feels twitchy/nervous/skittish and on rough sweepers feels downright loose and prone to head shaking unless the speed is sufficiently high (and I grip the bars fairly firmly). 

[/size]Conversely, Terry's RGS, on the same surfaces, feels very planted and simply goes where you point it. Both bikes sport the same tyres (BT45s) though his are new and mine are all but worn out (not to my usual Guzzi spec though :o :o ).


I expect new tyres will help the situation though I'm also considering fitting progressive springs to take away some of the slow speed harshness. Anyone have experience of progressive springs on Lavs?


I also have emulators fitted (thanks Red!) and have been following the other thread with interest. Will look into what emulator springs are fitted and determine a way forward from there..
 
The theory is, from what I have read. It's hard enough to adjust the damping for straight rate springs, to get it working for damping and adding a different spring rate for each additional amount of fork travel would need a super computer. The reason why progressive springs are used a lot on the rear is for pillion or solo use. From memory your a big strong lump like me, well hopefully less lumpy. I have 9.0 Eibock springs from Shock Treatment, bit less than $200, that's the strongest they do and will fit inside the fork. The std springs are 1.2 from the green book and pretty stiff.
The new tyre will help lots, the ones you have tend to scolop when worn. I have a new tyre on order as well as mine was less than rock steady on the last ride. I think I heard RGS have slightly more stable steering head angle in the frame as well?
 
Hello Andy,

To me it sounds like a problem with the rear suspension not the front.
I suspect the rear shocks are too soft and it's causing the bike to sit down at the rear.
Does the bike seem to run wide when exiting a corner?

Easiest check to make before spending any money is to stiffen the rear shocks to see if it improves the problems you are having.

Happy to discuss further....
 
I'm reading every word you guy's saying on this thread. Felt myself to be rather fortunate without too much Swallow or Hard hits so as long as I clean the forks every year or 2 but still not entirely happy.

Replacing worn front tires with various sizes, changing oil viscosity, cleaning tubes and emulators tend to work but not to perfection on our old bikes.

Rides like a Moto-Crosser below 30 mph and got to lay on the tank after 100 mph on my 71SF.

Over the years compared all the other bikes I've saddled, I believe that's the way the Laverda Breganzie 71 750FS is built and really can't get around it.

Never rode a Breganzie 3 Cyl but have ridden a Suzuki GSX-R 1100.
 
Dan#55 said:
Hello Andy,

To me it sounds like a problem with the rear suspension not the front.
I suspect the rear shocks are too soft and it's causing the bike to sit down at the rear.
Does the bike seem to run wide when exiting a corner?

Easiest check to make before spending any money is to stiffen the rear shocks to see if it improves the problems you are having.

Happy to discuss further....
Click to expand...


Hi Dan,
I have Wilbers on the rear end: stiffened up the preload prior to the trip down to Eastern Creek when the bike (suspension wise) ran fine (i.e. more load on the rear).


Compared to QLD the road surfaces are very different here in SA as is the nature of the bends themselves and, unless the road surface is pristine then the bike really is all over the place and feels decidedly dangerous. I've tried a variety of tyre pressures and found it seems to improve with reducing pressure. That said, I'm not sure I should be hooning around on 20psi f+r... :o :o .


On 'normal' pressures (i.e. over 30psi) the fork action over poor surfaces (i.e. ragged/micro bumps) feels both skittish and harsh as if both damping and spring rate are excessive whereas the handling and feel is fine over bumpier surfaces where the suspension seems to be working as it should. Hence I'm wondering if progressive springs might help over the minor/micro bumps...


A tyre change is due: that said the front tyre is not scalloped at all. Rear is becoming squared off and certainly contributing to head shaking and nervousness of the front, however, this shouldn't affect the fork action..
 
It sounds like the front forks want a little less preload (to soften the front). Progressive springs will do this but be careful to buy springs that are softer than your current ones at the initial stroke.
One thing to consider:
What type of roads do you do most of your riding on? (Do you want to compromise the handling on nice roads to do a little bit of riding on rough roads...)

I certainly wouldn't be changing tyre pressure to overcome the problem.

 
Choppy at slow speeds but working ok when going faster? Sounds like stiction to me.
 
Dan#55 said:
What type of roads do you do most of your riding on? (Do you want to compromise the handling on nice roads to do a little bit of riding on rough roads...)
Click to expand...
I want to be confident of getting around the corner!!😱😱
 
I think some basic's first though seems odd that most with emulators fitted are always chasing something on their bikes .....makes me think why they bother to be honest.
Ok so you need to go over a few basic's me thinks first to understand what the issue is could be something as simple stiction as Terry mentions ... am assuming he has ridden your bike as you have his RGS. Maybe its time just to swap your newly aquired MV for an RGS .  (bolt)
Here's what I think, especially after you bike was trailered down from Nth Qld with the front end tied down...  you gotta check the basic's first, which is you need to ensure the forks are actually parallel, to do so measure at the top under the triple clamp and then at the lowest point just above the dust cover... Then once you are confident there check that they are not twisted in the triple clamps.
So loosen the bolts on the triple clamps, the mudguard and the bottom pinch bolts and the axle then compress the forks several times.
If the forks were pinched or spread, this will allow them to find the position that gives the least misalignment.
Set the fork tubes so they both project the exact same distance through the tops of the clamps.
You can also do this if you put the bike on the centre stand then remove the top nuts and springs and then slowly lift the front wheel up, but e careful of the oil spilling out..  until the forks are compressed and let the wheel go. The weight of the wheel, oil and sliders should pull the forks down. If it doesnt slide smoothly up and down you will need to work out where the issue is.
Once you have it moving up and down freely tighten the triple clamp pinch bolts and retest.. then the front gaurd. The last things to tighten are the pinch bolts as this allows the axle/forks to find their most desirable position. Also you should then check your rear wheel to front wheel alignment as if the rear wheel is not true to the front can cause slow speed choppyness esp under power as the chain will be trying to pull the wheel instead of driving it.
 
Legs said:
No, No. Couldn't swap the Yellow Peril for the MV. Would have to have both 8)
Click to expand...


Cheers for this advice, Brett, will get into it this week when Anna's back at work... (down Cosi!)



Bring the Peril down Terry, I have someone who could paint it out into Steve Finch colours... :D :D
 
Reckon Bretts on the money ............ but uted, not trailered.

Have seen bikes parked in the corner of a ute, strapped down. The brake force, bumps, uneven strap tension etc have actually moved/twisted the forks in the triple clamps, particully if strapped down by the bars, and not the forks themselves. Resulting in piss poor handling.

I always tie down straight on and strap tie-downs to forks above bottom triple clamp.
 
chrisk said:
Reckon Bretts on the money ............ but uted, not trailered.

I always tie down straight on and strap tie-downs to forks above bottom triple clamp.
Click to expand...


But your bike doesn't go at all... :o :o
 
Brett said:
I think some basic's first though seems odd that most with emulators fitted are always chasing something on their bikes .....makes me think why they bother to be honest.
Ok so you need to go over a few basic's me thinks first to understand what the issue is could be something as simple stiction as Terry mentions ... am assuming he has ridden your bike as you have his RGS. Maybe its time just to swap your newly aquired MV for an RGS .  (bolt)
Here's what I think, especially after you bike was trailered down from Nth Qld with the front end tied down...  you gotta check the basic's first, which is you need to ensure the forks are actually parallel, to do so measure at the top under the triple clamp and then at the lowest point just above the dust cover... Then once you are confident there check that they are not twisted in the triple clamps.
So loosen the bolts on the triple clamps, the mudguard and the bottom pinch bolts and the axle then compress the forks several times.
If the forks were pinched or spread, this will allow them to find the position that gives the least misalignment.
Set the fork tubes so they both project the exact same distance through the tops of the clamps.
You can also do this if you put the bike on the centre stand then remove the top nuts and springs and then slowly lift the front wheel up, but e careful of the oil spilling out..  until the forks are compressed and let the wheel go. The weight of the wheel, oil and sliders should pull the forks down. If it doesnt slide smoothly up and down you will need to work out where the issue is.
Once you have it moving up and down freely tighten the triple clamp pinch bolts and retest.. then the front gaurd. The last things to tighten are the pinch bolts as this allows the axle/forks to find their most desirable position. Also you should then check your rear wheel to front wheel alignment as if the rear wheel is not true to the front can cause slow speed choppyness esp under power as the chain will be trying to pull the wheel instead of driving it.
Click to expand...

I feel a stupid question coming on here....With clip-ons I'm guessing I can't do the first method as the bars are attached to the forks?

 
clip ons shouldn't make any difference as they are separate units

i set my fork tubes in the top clamp such the front axle slides easily into both lowers
usually very close to dead even but sometimes there is a slight difference
otherwise same as Brett, work top down
 
Fitted progressive (Wirth) springs into my Darmah forks recently and went out with Terry for a blatt around the Hills on Sat to test them out.. Bike ran a treat: felt as though I was floating over coarse surfaces (road repairs and minor imperfections etc) yet still taught and well damped on proper bumps: rock solid cornering. Alas, not enough static/dynamic sag and so too too much preload and, unfortunately, the 'correct' springs seem to be a little too long for the forks (was a bitch to thread and re-fit the fork caps :o ).  ::) ::)


Either way, it's a positive result and I am looking forwards to trying some out on the Mirage..
 
One thing i fail to understand (yes, i fail to understand a lot but thats a different story) lots of owners are happy to replace the rear shocks with expensive items but very few get the forks fitted with cartridge conversion which surely is the best bet for getting the old forks to work as best as they are able.
FFFANARCHY
 
padlock said:
One thing i fail to understand (yes, i fail to understand a lot but thats a different story) lots of owners are happy to replace the rear shocks with expensive items but very few get the forks fitted with cartridge conversion which surely is the best bet for getting the old forks to work as best as they are able.
FFFANARCHY
Click to expand...
Probably because of the quick and easy swap. Forks take time, effort and skill to sort out.....
 
Yes my bike has Maxton converted forks and a Wilbers monoshock, plus wide tubeless radials and big brakes among a host of other upgrades
And yet...
I rode (at least) twice as hard back then on my stock 1200 with Cerianis all round, square Avon Roadrunners and stock brakes.

Makes me wonder.
I don't get it.
That is all.
 
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