DR650 Shock Rebuild

Discussion in 'Thumpers' started by P-nut, Jan 14, 2008.

  1. Eugene

    Eugene -

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    811
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    IN
    Thanks Rick.
    #81
  2. meanstrk

    meanstrk broke ass knee dragger

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    When are you looking at shipping the finished shocks back out? I get back from CA late Sunday!
    #82
  3. Eugene

    Eugene -

    Joined:
    May 29, 2007
    Oddometer:
    811
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    IN
    I measured my sag today to get a reading before I add an aftermarket tank. The bike has all stock suspension and a full tank of gas. The only add on bits are a Corbin seat, rear rack, and dirt bagz racks. I should have put on the stock seat and taken off the racks to get a completely stock reading but didn't think about it until after I was done.

    I weight right around 160lbs and I wasn't wearing any gear.

    Rear:
    Static: 45mm(1.77 inch)
    Race: 93mm(3.66 inch)

    Front:
    Static: 37mm(1.46 inch)
    Race: 62mm(2.44 inch)

    The front seems to be way off. Does this sound right??

    As for the rear, I haven't made any changes to it. I bought the bike used and I've only had it for a little while. I knew I was going to do something to the suspension so I haven't touched the preload. By the looks of it, my preload is cranked up?? It's somewhat close to the end of the threads. I'm a dummy when it comes to suspension. If it's cranked up, what will it do to my readings if I take it the other way? I'm trying to get a better understanding on the spring rate. Here's a pic:

    Sorry for the big picture. :uhoh

    [​IMG]
    #83
  4. meanstrk

    meanstrk broke ass knee dragger

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    Yep. Your preload is cranked up pretty high!
    #84
  5. Rusty Rocket

    Rusty Rocket Life behind "Bars"

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    Measure the sag from a point vertical above the rear axle. A spot on the fender or frame will do. Unweight the bike by lifting the rear till the suspension tops out. have your assistant measure to the spot from the axle. (you can do this on a stand) then let the full weight of the bike (with gas) settle on the spring. measure again to the same spots. Subtract the smaller # fron the larger#.This is static sag. Sit on the bike (with riding gear) both feet off the ground. Measure again. Subtract the new measure from the original measurement with bike unweighted. this is race sag. If race sag ,3.5" - 4.0" or so can't be reached with a static sag of approx 3/4" you will have to get a different spring. Keintech can tell you which will work best in your application. Luggage and larger fuel tanks may have to be considered.
    #85
  6. Eugene

    Eugene -

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    You don't approve of my duct tape, curtain rod, hex wrench, zip tie method? :lol3
    #86
  7. Rusty Rocket

    Rusty Rocket Life behind "Bars"

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    Frankly, I woke up screaming!!:D
    #87
  8. NC Rick

    NC Rick Cogent Dynamics Inc

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    Man, I have had my hands full here guys. I have not been able to keep up with this thread. Eugene, don't worry about how many threads are left on the shock, can you check what the installed spring length is? since you have your sag set you have plenty of threads left and I don't think you have that much preload. The minimum I have seen is 250 mm installed length.

    Check this afternoons photo:
    [​IMG]
    I did not hat time left in the day for shipping. Rons spring is white :deal
    #88
  9. neepuk

    neepuk Such a drag...

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    I want in on the next build. PM coming.
    #89
  10. NC Rick

    NC Rick Cogent Dynamics Inc

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    I need to get the shocks for the next run coming. I would like to have them by late next week. Depending on when they get here, a two week turn around is likely (it could be a little better). Please get with me quickly if any of you would like to be part of the next built. I have 2 more to put together from this first build. a couple others are shipped.

    Eugene's sag is close on the rear but the unloaded sag is too much, indicating a stiff spring. Also by PM I found that the spring preload is only at about 8mm. For a spring of that length we would expect to see 15-20 mm preload. All that is is another indicator of the spring rate.
    #90
  11. switchback

    switchback Eatin' Dirt Since 1982

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    Email sent.
    #91
  12. Bgunn

    Bgunn Mucha distancia

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    Pm sent as well :deal
    #92
  13. Rusty Rocket

    Rusty Rocket Life behind "Bars"

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    "I love it when a plan comes together." Geo. Peppard in the A-Team

    Those are some good looking suspenders.
    #93
  14. ThePearl

    ThePearl Adventurer

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    In the next couple of weeks I'm doing a DRZ rear shock conversion to my 2004 DR650. If that doesn't do what I'm looking for, I may be contacting you for a new rebuild. They look awesome!!:clap
    #94
  15. eyedragaknee

    eyedragaknee McGuyver

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    Stock spring 2007 DR650, lowered both ends. 175lb rider butt neeked after a good dump.

    I just checked the static sag on the rear of the pig and it is 2" with the preload all the way wound up tight. Nothing left. I don't think the leverage is different with it lowered? Doesn't the setup just move the eye mounting in the shock and the spring on the same pivot points as the standard setup? That would mean the leverage doesn't change, just the "location or length of the extended shock? Same as a ride height adjuster.Basically putting a shorter shock in with the same spring rate?

    This seems like too much static sag. Rider sag adds another good 2" or maybe a tad more.

    31" fully unloaded
    29" bike only
    27" bike and rider, maybe a little less

    perpendicular to ground on centerline of rear axle. Something seems weird?
    #95
  16. eyedragaknee

    eyedragaknee McGuyver

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    Almost all the preload out of the rear spring.....

    31" unloaded
    27" rider
    28 1/2" bike alone

    1 1/2" difference.

    It is still a friggin pogo stick. High and low speed compression and rebound would be nice.
    #96
  17. NC Rick

    NC Rick Cogent Dynamics Inc

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    :lol3

    Sometimes pogo sticks are fun!

    Using the shock in the lowered position puts the linkage in a different part of the leverage curve I guess but it really should not change the basic leverage. As the rear of the bike goes down, the weight transfers to the rear as well. When the rear shock is used in the "low" position, the spring clip should be flipped and that puts extra preload on the spring as well as positioning the big steel washer to restrict the shock travel so the bottoming point on the suspension is still the same (this avoids the wheel hitting the fender or the skid plate contacting the ground sooner than intended. This reversible spring clip is one of the reasons there is so many threads above the spring on the shock body.

    If we build a short version of the shock, we can not keep the convertible feature. The shock is purpose built to give the low height and proper spring preload. Since spring rates are relative to the travel, reducing travel will make the required wheel rate be higher. In other words, the less travel needs a stiffer spring, all things being equal.

    With regard to the DRZ shock, the new DR 650 shock is giving better performance that the Dz in Dual Sport use. I owned a DRZ E that was street legal up until last year and my friend Jerry (a DRZ s owner) has ridden on my DR with the new shock and wants me to make his DRZ work like the DR does. The adjuster on the DRZ is better than the stock DR but I really have no idea how it will work on the DR. Is the eye to eye length and stroke the same between the DR and the DRZ??
    #97
  18. meanstrk

    meanstrk broke ass knee dragger

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    Was mine a white spring when I sent it? I can't remember. Too much of :1drink since I pulled it I guess!

    I need to pull the Aprilia shock and send it to you some time..........
    #98
  19. NC Rick

    NC Rick Cogent Dynamics Inc

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    Meanstrk, you shock should be at your house today.:D
    #99
  20. meanstrk

    meanstrk broke ass knee dragger

    Joined:
    Nov 16, 2007
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    Location:
    Carthage, NC
    And you KNOW I am looking forward to seeing how she performs now!

    Gonna have to order some emulators next I guess.........:D