Ridemalibu Motorcycle Rentals & Tours – Los Angeles CA
  1. Ciao Guest - we've been proud to harbor such wonderful Guzzisti camaraderie since 2005, for FREE. Times have changed, and so have the attitudes and expectations of far too many. Starting Jan 1, 2020, we will likely be shifting to a paid to participate format. You will still be able to read for free. This should alleviate all of the negativity that the free social media channels have created. If you are a donor or customer of ours, you're in, just use the Contact tab above if your account is not already promoted, or you can Upgrade your account once signed in. Or the Donate tab above is another option. We look forward to continuing this service to the Guzzi community, but it is not cheap or easy to host and maintain. We wish you the best for the Holidays and in the New Year.

Now for suspension

Discussion in 'Custom Guzzi Builds' started by Desmo007, Jul 21, 2019.

  1. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
    Alright guys, the quick rundown is that I have a V11 that I stripped down to a LeMans weight.

    My question is, do you think the stock front end can be adjusted to the new weight, or should I be looking at replacing internals? I’m dialing in the rears with a set of Ikons at the moment.

    Thanks!!!
     

    Attached Files:

  2. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,838
    Likes Received:
    248
    Location:
    B'more, Md
    You can replace the springs with the right spring rates. And dampening can be adjusted. But first I would measure sag and see where you are, how far off the spring rates are (both front and rear).
    Spring rates first, then worry about dampening.
     
    Desmo007 likes this.
  3. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
    Well, I took some rough measurements and wow, it doesn’t sound right. Although I’m unsure whet the numbers should be for a LeMans style Guzzi.

    M1= wheels off the ground
    M2 = weight of the bike upright
    M3 = me with riding gear

    Front
    M1 = 508mm
    M2 = 495.3mm
    M3 = 482.6mm

    Rear
    M1= 431.8mm
    M2 = 419.1mm
    M3 = 393.7mm
     
  4. GT-Rx®

    GT-Rx® Administrator Staff Member GT di Razza Pura

    Joined:
    Jul 1, 2009
    Messages:
    10,637
    Likes Received:
    2,913
    Location:
    Malibu
    I have ~35 years experience in suspension tuning (27 racing), and 20+ years in Guzzi specific modification. See the Archive tab above for more info.
    In short:
    Front wheel travel: 130mm/3 = 43.33mm target total travel with you seated.
    Rear wheel travel: 89mm/3 = 29.66mm target total travel with you seated.
    Yours:
    Front: 26mm
    Rear: 38mm

    So WAY too firm in front, and too soft in the rear. So add preload on the rear shocks, and you'll have to change out the springs and experiment with the fork oil weight, unless you dig into the internals. Are your forks the damping adjust type on the top, or like the Jackal/Stone with no adjusters on top?
    Once sag is sorted then you have to balance the damping. I could save people a TON of time in wasting money, as I've been there done that 10x over on the Tonti. ;)
     
    Desmo007 likes this.
  5. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
    THANK YOU.
    This gives me a solid starting point.

    I do have the rebound and compression adjusters on top. Dumb question, (I’ll investigate) but does Todd sell the springs for these bikes or should I ask around?
     
    Last edited: Jul 22, 2019
  6. GT-Rx®

    GT-Rx® Administrator Staff Member GT di Razza Pura

    Joined:
    Jul 1, 2009
    Messages:
    10,637
    Likes Received:
    2,913
    Location:
    Malibu
    Welcome, and you won’t get far on the front without digging into them. Happy to be of help direct email with available options, but the adjustable forks only leave this one easy option of just fork springs; https://gtmotocycles.com/collections/suspension/products/california-1100-s-fork-kit - or you can go down the path I did almost 18 years ago, and it took me ~5 years to figure out in a mediocre sense.
     
    Desmo007 likes this.
  7. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
  8. Godfrey

    Godfrey High Miler GT Famiglia

    Joined:
    Oct 1, 2017
    Messages:
    844
    Likes Received:
    507
    Location:
    San Francisco Bay Area
    I can speak for how excellent and worth it the Matris cartridge fork kits are. We fitted one (with the correct spring rates) to my V7III Racer and it has completely transformed the front end of the machine. Absolutely well worth every penny. And you can see immediately when you open the box that the pieces are superbly, beautifully made and finished—true quality stuff.
     
    Desmo007 and GT-Rx® like this.
  9. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,838
    Likes Received:
    248
    Location:
    B'more, Md
    I will add my two cents, because, why not. It is free, so it is worth what you paid for it.
    Your preload looks about right based on the amount of sag under just the weight of the bike. But, as Todd said, your sag with you on board is too little up front and too much out back. That means your front springs are too stiff and your rear springs are too soft. You can play with preload to adjust the sag with you on board, but adding preload (or removing it) does not change the rate of your springs. And your front springs appear to be too stiff while your rear springs appear to be too soft. Preload can make it better than it is, but only different springs are really going to make it right.
     
    Desmo007 likes this.
  10. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
    I just saw these responses, and they are very appreciated. So I should go stiffer rear spring, one step up I’m guessing. I have a free return on the springs, but will be reaching out to Todd for the front end. (Yikes) As far as the rears, I have these options:

    “So if you have a black code 230 spring fitted which is too hard, then a code 249 (11/16/22) or code 613 (9/13/18) spring will give you a 'softer' ride quality.

    We have the code 613 - the lighter of the 2 replacement spring options in stock, the code 249 springs will be back in stock the week commencing 8.4.19. Please let me know which one you would prefer, essentially a 'little' or a 'lot' softer in very basic terms.”
     
  11. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,838
    Likes Received:
    248
    Location:
    B'more, Md
    Well, I prefer stiffer, so I would try one step softer in the rear. Also, you don't have a lot of rear travel available, so I would want less rear sag which would leave more travel available to absorb bumps. Finally, I like a higher ride height as it means more ground clearance.
    But it is your ride and you need to make it how you want it, based on you and what you need.
    What is key in my opinion is that the front and rear work together. I try to keep the sag similar between front and rear. That helps maintain balance.
     
  12. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
    You do mean one step stiffer spring, as it sounds like my rear is too soft, front too stiff. Isn’t there a sweet spot within the stroke that’s optimal? (My experience is solely on dirtbike suspension)
     
  13. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
    Hey Todd - I think I’ll bite the bullet on the front end kit. What are the logical next steps? Thanks!
     
  14. GT-Rx®

    GT-Rx® Administrator Staff Member GT di Razza Pura

    Joined:
    Jul 1, 2009
    Messages:
    10,637
    Likes Received:
    2,913
    Location:
    Malibu
    Really difficult for me to track posts here for products. Email is best, or purchase online and I'll be in touch for specifics. click link above.
     
    Desmo007 likes this.
  15. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
    Ordered the good stuff, hopefully the last of the big ticket items. But hearing your feedback, it sounds worth it.

    I managed to get the new set of Ikons from the original 38 to the 30mm sag on the rear. (Target of 29.66,as Todd states) I’m hoping it’s close enough, as I’m plum cashed out on this one for a while!
     
  16. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,838
    Likes Received:
    248
    Location:
    B'more, Md
    The way you tell if your springs are the right rate or not is by setting them to the required sag with you on the bike and then measuring the sag under just the weight of the bike itself. If your springs are too soft you will have too little sag under just the weight of the bike. That is because you had to add too much preload to the spring to get the sag where you want it. And adding preload does not make a spring stiffer, it only increases ride height.
    Generally, you want sag to be around 25 to 30 percent of total travel with you on the bike and around 10 to 15 percent under just the weight of the bike.
    I would guess based on what you previously posted that now that rear sag with you on the bike is where you want it you likely have way too little sag under just the weight of the bike.
     
    Desmo007 likes this.
  17. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
    Crap, so I checked the sag under bike weight and I get very minimal. (1.59mm difference) so if I am understanding correctly, weight of bike 10-15, with rider 25-30, so close to half for each. Does the Shock length play a part at all, since the wheel hangs as far as the shock allows?
     
  18. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,838
    Likes Received:
    248
    Location:
    B'more, Md
    Shock length is not really directly part of the math, although it is a factor as the numbers are based on percentage of suspension travel and the length of the shock and it available travel determine overall suspension travel.
    Your lack of sag was predictable based on the numbers you posted. As you add or remove preload to add or remove sag with you on the bike the same amount of sag is added or removed under just the weight of the bike. Running a spring that is nearly topped out under the weight of the bike is not going to work as well as your suspension should work, no matter what you do with dampening.
    They offered to upgrade you to a different spring. I would take them up on it.
    Adding or removing preload does not make the spring stiffer or softer. It only raises or lowers ride height. If you spring is too hard (or too soft) only a spring with a different rate will fix that.
     
    Desmo007 likes this.
  19. Desmo007

    Desmo007 Tuned and Synch'ed GT Contributor

    Joined:
    Oct 5, 2018
    Messages:
    82
    Likes Received:
    7
    Location:
    Aptos, ca 95003
    Makes sense and thanks for sharing. Very good stuff.
     
  20. Godfrey

    Godfrey High Miler GT Famiglia

    Joined:
    Oct 1, 2017
    Messages:
    844
    Likes Received:
    507
    Location:
    San Francisco Bay Area
    Yeah ... I had Todd get me the next-up rate for Racer's Ohlins rear suspension units. When they were being fitted (along with the fork kit), the mechanic and I set up the bike to the sag specs.

    Then I sat on the seat and bounced it up and down a few times. We stiffened up the rear a little bit and loosened up the front a little bit based on my "seat of the pants shock dyno." ... :D

    The only modifications I've had to make to the suspension settings since have been to tighten up the jounce damping in the rear by two clicks and tighten up the rebound damping in the front by two clicks after I'd ridden the bike another four hundred miles ... I might have the ends swapped around, but you get the idea. It's just about as perfect as I'll ever need.

    G
     
    Desmo007 likes this.

Share This Page