06-10 GSXR750 set up numbers

Discussion in 'Tech' started by Bob Miller, Feb 18, 2021.

  1. Bob Miller

    Bob Miller Well-Known Member

    Good morning,

    Setting up a 2007 GSXR750 i am rebuilding and looking for some set up numbers to start with.
    The bike is set up with Ohlins 20mm cartridges up front including Ohlins extended fork caps and a Ohlins TTX36 shock.

    Understanding the raising of the entire bike is the standard practice can anyone offer a general starting point for the Eye to Eye of the shock and number of mm over stock the front is typically raises (tubes lowered) ?

    I have not heard back from Ohlins USA yet regarding starting points on the equipment for rebound and compression. Both ends are fresh rebuilds and seals though used. Both ends are deemed to be sprung properly for my weight and currently set sag at 25mm.

    Thank you
    Bob
     
  2. Daniel06

    Daniel06 Well-Known Member

    There used to be some very in depth threads on the gsxr forum and the g ixxer forum. To my recollection the eye2eye was between 327mm and 331mm. I used to run 328 I think. Stock is 323 I think. Forks flush or if running extenders 5 mm down. Check those other forums if they still exist. Pages of great info.
     
  3. Bob Miller

    Bob Miller Well-Known Member

    Thanks you Daniel. Yea i have cruised around the threads a bit and found quite the array of numbers. There was enough chatter and counter posts that it quickly became quite confusing to what was a sensible start. Tend to get more straight forward track bias information from all of you on here.

    Based on your numbers you were running your entire bike 5mm higher with front and rear lifted same?

    Thank You
    Bob
     
  4. Daniel06

    Daniel06 Well-Known Member

    Yes. I liked back then 328 rear and up to 10mm recessed on the front. Flush front and 325 is a good starting point if you don't have extenders. Too high in the rear without extenders caused it to spin up if I remember right. So I wouldn't go 328 without extenders. This is all from memory. 325 and flush is a safe start though.
    Edit: See you have extenders.
     
  5. SPL170db

    SPL170db Trackday winner

    There's a bit of variance based on personal preference, but my setup was 535mm front and 328mm rear.

    535mm is measured from the top surface of the lower triple clamp to the middle of the front axle. 328mm on the rear overall eye to eye length, which I believe required using a 5mm spacer on the shock clevis plus maxing out the Ohlins shock ride adjuster which is 8mm I want to say.
     
  6. Bob Miller

    Bob Miller Well-Known Member

    Thanks SpL170! Thank your for the numbers. Seeing your rear was up +8mm over stock was your front up 8mm too...with your bike raised equal as Daniel's was?
     
  7. Bob Miller

    Bob Miller Well-Known Member

    .....from the responses you guys are providing im trying to decipher if there is a bias to have the bike raised up equal front/rear or if there is a bias to have one end adjusted + or - over stock stance ratio.
     
  8. DBConz

    DBConz Registered Idiot

    525mm from center of axle hole on the fork to the top edge of the lower triple
    325mm center eye to eye on the shock

    my sag settings: 34.5mm front, 27mm rear

    this is for a 600, but same bike
     
  9. Daniel06

    Daniel06 Well-Known Member

    I think SPL is right in the ballpark. Thinking now, 321 might be stock shock link.

    My best guess without measuring is the front will raise more than rear. Rear pivots differently than front forks. A rear ride height adjustment makes a larger multiplier than front.
     
  10. RM Racing

    RM Racing Tool user

    5mm at the rear shock is very close to 10mm at the axle....2:1 wheel rate ratio. Forks are 1:1 at the axle. Keep that in mind.
     
  11. Bob Miller

    Bob Miller Well-Known Member

    RM......did not consider that! Thank you. Thanks for the numbers guys!
     
  12. Gerry Gentry

    Gerry Gentry Well-Known Member

    327mm eye to eye in the rear and up (actually down through the triples) on the forks is the way to go. If you can't get the shock to extend that far use spacers under the clevis at the top of the shock between the frame and clevis to get the total overall dimension. For example: 321 mm of shock and 6mm of shim gets you to 327mm total. That year GSXR likes to be raised up at both ends. The farther down in the triples (i.e. 10 mm vs 5mm) from stock the more effort for the rider to turn the bike. Said another way the higher the front is off of the ground, compared to the rear, the harder to turn the bike in. Some of it is rider preference. Some of it is geometry affect (seen in the tire wear). The aspect ratio of the rear tire will affect the rear overall height also so keep that in mind. Get the rear to high and the bike will be tale happy (dragsters don't handle well on a slalom course). We have run as much as 16mm down through the triples but are working back from there to make it easier to change direction. The markings on the extenders from Kyle are exactly 2mm per line. Makes it easy to keep track of.

    Regards,
     
  13. Bob Miller

    Bob Miller Well-Known Member

    Tnank you !
     
  14. DBConz

    DBConz Registered Idiot

    just changed my forks to 535mm last night.
     
  15. Bob Miller

    Bob Miller Well-Known Member

    Is there a general accepted measure point for front so language is uniform sharing numbers.
    I am use to numbers being shared from tubes above or below upper triple.
    DB your measure method could be impacted by the sag setup couldnt it?
     
  16. DBConz

    DBConz Registered Idiot

    [​IMG]

    Start from here and measure to the center of the front axle.


    Sent from my iPhone using Tapatalk
     
  17. Bob Miller

    Bob Miller Well-Known Member

    Wont that number be impacted by how much your sag is set? My sag numbers are often variable from stiction, my weight and stuff. Do you run into this at all?
     
  18. RM Racing

    RM Racing Tool user

    Top of lower triple to axle with the front wheel off the ground, no sag. Forks can be set up with different internal spacing, which makes the "above the top triple" measurement inconsistent.

    It's always better to make that measurement at full stiff preload as well, which extends the top out spring in the fork. You have to remember to unwind the preload before you ride.

    Bikes with potentiometers make all of this much simpler.
     
  19. Bob Miller

    Bob Miller Well-Known Member

    Ahh makes sense!!
     
  20. Boman Forklift

    Boman Forklift Well-Known Member

    Good advice above. On my son’s R6 the top out springs were so light I could simply pull down on the front wheel while making the measurements.

    I actually never thought about winding in preload all the way, that may have changed it?

    I do know on R6 Ohlins rear shocks they make a tool to spread the shock and get a true eye to eye reading. You can also wind in hydraulic preload to help get there, but I don’t actually know if that extends it all the way, I’m sure @RM Racing can tell you for sure.

    I also think a GSXR shock works the same way but I don’t have experience on those.
     

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