Africa Twin CRF1000L suspension

Discussion in 'Japanese polycylindered adventure bikes' started by uk_mouse, Jun 22, 2016.

  1. Motociclo

    Motociclo Long timer Supporter

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    From memory, 87 to 91 CR's used a fork similar to these. Wear parts and valves interchangeable.

    Have had forks on my Af Twin apart a couple of times for revalving work, 30,000km, and perceptible wear on inside of the upper legs.
  2. Motociclo

    Motociclo Long timer Supporter

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    He is my latest change to valving in Af Twin.
    There may seem to be a large amount of shims, but difference between 0.15 and 0.10 shims is roughly 3.5 on paper. In forks at least.
    Overall haven't added another of shims to each stack. Stack Heights are not much different.
    My logic behind this is, the thicker shims are more likely to be a bit harsher than thinner shims.
    The damping is a bit greater with these changes, but it works much better than previous effort.
    All based on stock clicker settings.
    Did do some experiments with clamp shims and a Kyb piston in shock, but settled on this.

    Forks, comp.
    17*0.10, (11)
    11*0.10
    17*0.10
    15*0.10
    13*0.10
    12*0.10
    10*0.10

    Forks, rebound
    17*0.15,(5)
    15*0.10
    12*0.10
    9*0.10
    8*0.2

    Shock, comp.
    40*0.15,(12)
    28*0.10
    40*0.15,(2)
    38*0.15
    36*0.15
    34*0.15
    32*0.20
    30*0.20
    28*0.20
    26*0.25
    24*0.30
    22*0.30
    20*0.30

    Shock, rebound.
    36*0.15,(10)
    30*0.10
    36*0.15
    34*0.25
    32*0.25
    30*0.25
    28*0.25
    26*0.25
    24*0.30
    22*0.30
    20*0.30
    18*0.30
  3. Motociclo

    Motociclo Long timer Supporter

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    I meant no perceptible wear. Tunes seem okay.
  4. Griff2

    Griff2 Griff

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    I was thinking that way also but from memory there is a bushing on the top of the inner tube and it acts directly on the inside of the outer tube. From what I can understand that area is where the wear is occurring.
  5. Phlyn' Phil

    Phlyn' Phil Been here awhile

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    Quick ? for the stock suspension guys, as Im no guru for sure, but I notice two major things, front fork dive and kinda harsh ride over little bumps like washboard or puddle divots. So whats the consensus on settings to make this bike happy, I am 250# w gear and sometimes load up another 60# when traveling. Quick ideas for the stock suspension settings?
  6. Junglejeff1

    Junglejeff1 Long timer

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    Jack your preload up and turn your compression soft by like 6 to 8 clicks for starters. Less dive and less compression damping.can only get so much out of this but its what I did when I had stock springs.Helped with the small hits.
    Benjah likes this.
  7. Junglejeff1

    Junglejeff1 Long timer

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    Thats the place . I've never really had a problem with them wearing fast.My 2000 yz is starting to get a little loose that new rebuild will not get rid of but still works well.Did have problems with some aftermarket seals in past.I have had great luck with oem seals but aftermarket never seem to last long.The seals they call leak proof are the worst.Never had them last more than 2 weeks on older bikes(gave them 3 trys on moto bikes).I know why but will not get into it here.Going to try the seals mentioned here by the techs and see how they hold up.We rebuilt my step sons forks using seals from outlaw (very cheap parts) and he has been pounding the hell out of bike and still not leaking.Anyway I think the forks on the AT will be fine as long as clean oil is in there . I've had so many old bikes with small forks that held up fine that weighed just as much and more.Imagine the stress thats on gold wing forks"".
    Griff2 likes this.
  8. Junglejeff1

    Junglejeff1 Long timer

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    You are as bad as me lol.I have found in setting up suspension in my offroad bikes that doing the same stack with more thinner shims is more compliant.Starting playing with it after reading a article on setting up rock crawling trucks.I get my info were ever I can lol.
  9. Junglejeff1

    Junglejeff1 Long timer

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    I tried your 1st post in shock and ended up thinning out face shims because wify complaned of sharp jolts.Have to play with it more as still some there with compression backed out.
  10. Benjah

    Benjah Been here awhile

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    Did the same front and back + add a lot of rebound. I'm fairly fussy about suspension but I find this setup pretty good for solo riding without luggage, which is the only kind of riding I do.
    Junglejeff1 likes this.
  11. NSFW

    NSFW basecamp4adv Super Supporter

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    for a year i got away on the stock suspension. weigh 195#. jacked up the preload. thought that was good enough. last week, i put heavier springs and the difference in the performance was huge. asking myself why waited that long when the inevitable is bound to happen anyway.

    biggest difference is the bike doesn't rock anymore after the wheels are at a full stop. before, when i plant my left foot on the ground, the bike was still bouncing. maybe it's just me and the settings.
  12. Motociclo

    Motociclo Long timer Supporter

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    First post was second change and was a bit firm for sure. This latest version feels better. I am likely to stick with it for now!!
  13. Junglejeff1

    Junglejeff1 Long timer

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    Cool.will try
  14. Motociclo

    Motociclo Long timer Supporter

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    For what is worth I think I have worked out how Cogent came to the spring rate.
    If what I worked out is on the right track,. 0.82kg fork and 10.4kg shock.
    I think the logic behind this is to maintain stock preload settings to get favourable sag settings.
    Makes more sense to me now.
    Junglejeff1 likes this.
  15. Junglejeff1

    Junglejeff1 Long timer

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    I had my rebound on shock turned out only 2 clicks and was not enough.Was a basketball in whoops 2 up.not bad 1 up as I was not bottoming as much.The slower pace 2 up really slammed the suspention down hard comong out of whoop.When I put the 10.4 on I basically had no rebound and had to revalve.Trying to control suspention 2 up is hard.We wiped her out on a powerline today but it was my fault lol.Going through deep grass and not seeing holes was not good.
  16. NavigatorCA

    NavigatorCA Been here awhile

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    Just a quick note regarding stock suspension.

    I followed earlier recommendations and verified default settings.

    In my case, the punch marked adjusters were all good. However, un-punced fork compression damping was set, by the look of it, 8 clicks from soft setting instead of hard. Moreover, the forks were set one click apart from each other.

    It is definitely worth checking default setting first...
    jantomas likes this.
  17. Griff2

    Griff2 Griff

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    With regard to the aspect mentioned above regarding a harsh ride over little bumps, I initially backed off the compression damping on the forks because that was where I was feeling this the most. However I was still getting the harsh feeling and it seemed to be getting worse. I also noticed some friction/stiction in the forks. I mentioned this on here and a couple of inmates mentioned applying either silicone grease or fork oil to the steel fork sliders after washing the bike because the washing agent can tend to wash all lubricant off their surface. I did what they suggested using AFC50 and it made a significant difference. When applying this lubricant ,I pumped the forks several times and wiped off excess without removing the coating completely. Worth a try imho.
  18. Motociclo

    Motociclo Long timer Supporter

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    Forks that are under sprung and have preload wound right up plus having valving that is too soft can make hitting reasonable bumps feel harsh.
    It is blowing through stroke too quick.
    Wouldn't hurt to check your fork alignment also.

    Never been real keen on adding lube to fork legs. Only atracts added dust to area. Keeping legs clean will help seal life.
    Only ever had a couple of leaky forks seals. These bikes all had over 100,000 kms on seals when this happened.
  19. NavigatorCA

    NavigatorCA Been here awhile

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    I ride solo and, with 75 kg with gear, my rider sag is spot on at 32% with default settings (no need for extra pre-load). I also noticed harsh ride over smal repetitive bums (washboard like), not nessesaraly over single bums...
  20. Motociclo

    Motociclo Long timer Supporter

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    Too much rebound. Your pretty light.
    Suspension is not recovering and packing down. Will make it harsh also. Dial rebound a it.
    Your pretty light. Stock springs will work for you. Your right in the target range of stock suspension.