• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Fork static sag question

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

Guest
My front end on the 80' 1000G feels 'sensitive', meaning it seems to pick up on every rut in the road moving around a 'bit' more than I like. Front has progressive springs, rear has progressive as with the stiff spring. I measured static sag according to the sonic sight. 140mm full extension, 87mm pushing down/let settle on the front end, 100mm lifting up/let settle on the front end. Calculation equals 46.5mm which is 33% of total sag. Does this number explain why it feels the way it does? By increasing the PVC spacer by 1/4 or so, that will decrease my static sag and improve the feel?
 
If that sag figure is unladen - ie without the rider - I'd replace the fork springs. If it's with the rider aboard, and you're using 1/3 of the fork travel before you move off, it's still too soft.
IMO you should be looking for about 25mm of sag on something the weight of the 1000G - with the rider aboard.
 
Those numbers are with the rider on the bike. Does this explain why the bike seems to pick up everything on the road? If I remember that last time I put the PVC spacers in they were pretty dang tight to get everything back together, I'll pull them out and see what length they were.
 
Current PVC spacer is 46mm ( 1 3/4 inch), it's going to be pretty darn tight to get a 2 inch spacer in there.
 
If the springs are the right weight you shouldn't have to compress the spring that much to get the cap back on. On my 1000 with the Progressive brand springs and spacer combination I use I only push down on the cap about 1/2" so total compression once the cap is installed is around 1" at most. I've also settled on 15W fork oil. Unladden sag last time I checked was probably slightly more than 1", didn't check ladden sag but I do use tiewraps to measure how the suspension is working under different scenarios such as sporty riding and close to but not bottoming under tire howling full braking. My Progressive springs were pretty much a full length spring so my spacer length is very small. If you're running shorter springs with an overly long spacer than could possibly result in the springs getting coil bound on full compression or being very stiff once you get much beyond the initial sag. Are you trying to compensation for the Windjammer? If you are it might be time for a step up or two in initial spring weight so you can reduce your spacer length.
 
I'm using Progressive springs in the G with 15W oil. I've increased the spacer from 45mm to 52mm with a noticeable improvement, it now has a unladden sag of 38mm. Running the bike hard through corners has been pretty good, the issue I've been noticing is at low speeds, it tends to 'track' for a lack of a better word, seems to move around a lot. I was reading one of Dan's threads and on his 80' 1000G, with progressive springs, he put a 90mm spacer in there :eek: I've got 20 lbs on him and a Vetter so there's that to consider.
 
That's all lot of weight up front. Just curious, did you put a fork brace on that one?
Something here is not making sense unless something else is out of wack.
 
azr said:
Those numbers are with the rider on the bike. Does this explain why the bike seems to pick up everything on the road? If I remember that last time I put the PVC spacers in they were pretty dang tight to get everything back together, I'll pull them out and see what length they were.
Click to expand...

When I mentioned how hard it was for me to push down to stuff springs in, Rich as Sonic posted in reply that springs were too weak, I had had preload set mainly to avoid bottoming out (during hard braking using the zip tie method) so I have now purchased a set of 1.0 Kg/mm straight springs from Sonic but have yet to install.
 
Sandy said:
That's all lot of weight up front. Just curious, did you put a fork brace on that one?
Something here is not making sense unless something else is out of wack.
Click to expand...

Yes the G has the more modern Tarozzi fork brake. What part about the numbers isn't making sense to you?

posplayr said:
When I mentioned how hard it was for me to push down to stuff springs in, Rich as Sonic posted in reply that springs were too weak, I had had preload set mainly to avoid bottoming out (during hard braking using the zip tie method) so I have now purchased a set of 1.0 Kg/mm straight springs from Sonic but have yet to install.
Click to expand...

I've got Sonic springs in the 78' and do prefer them but as the G isn't for hard riding I'm hoping I can make the Progressives work, there's not reason I should be able to.
 
azr said:
I've got Sonic springs in the 78' and do prefer them but as the G isn't for hard riding I'm hoping I can make the Progressives work, there's not reason I should be able to.
Click to expand...

If the sag is too high due to too low of a spring rate, you can increase spring rate by cutting off the flatter coils of the spring. I believe Ed (Nessism) has done this up to about 4" worth (maybe even a little more). It can give you easily a 10% increase in spring rate.
 
posplayr said:
If the sag is too high due to too low of a spring rate, you can increase spring rate by cutting off the flatter coils of the spring. I believe Ed (Nessism) has done this up to about 4" worth (maybe even a little more). It can give you easily a 10% increase in spring rate.
Click to expand...


Yes I've read that, but these are relatively new progressive springs within the last 3 yrs or so.
 
azr said:
Yes the G has the more modern Tarozzi fork brake. What part about the numbers isn't making sense to you?
Click to expand...

I don't know exactly. With what you've said you have and what Dan has, even if the setup isn't bang on you shouldn't be having a driveability issue. It might feel a bit tight or loose and need some fine tuning, but it should track properly. I know you're meticulous when going over a bike but I'm now wondering if you're chasing ghosts in your forks and the actual problem might be somewhere else. Maybe the head bearings, assuming you've changed them, have shifted a bit and need retorquing? I asked about the fork brace because I have the same one on my 1000 and it actually made more difference for low speed tracking and feel than it does at high speed. But you've done that so.......
 
It's got new head bearing, but you're right they did loosen up a bit last year and needed tightening, I'll check them. It's likely as well that I'm being a bit 'too' picky. The bike rides great, corners great, etc..... It's like vacuum synching, you can chase those levels so much trying to get the 'perfect' that you can spend hours doing basically nothing.
 
If it is still a little unsettled with sag in the right range, time to look at the front tyre and it's pressures. Some brands are more directionally stable than others.
Re the fairing - frame mount or fork mounted ?
 
I noticed a improvement in the subtle tracking after adding emulators which is just not there without.
 
You must log in or register to reply here.
Back
Top