Spring rates

Discussion in 'Hacks' started by Ridn3, Sep 30, 2015.

  1. claude

    claude Sidecar Jockey

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    So Dave you are saying your system is 'GOOD ENOUGH'. You started this 'good enough' stuff if you remember. We have one rig that has been abused very hard on three contents with our 'good enough' trail reducer and no problems not to mention others . Have never had an issue with the fork angle being slightly off from stock. Seriously though the reducer HAS TO BE DESIGNED PROPERLY or issues can happen.
    #21
  2. claude

    claude Sidecar Jockey

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    Can't argue with that at all Dana!! Sometimes it kinda sorta makes sense just to ride the darn things and have fun. LOL
    #22
  3. davebig

    davebig Another Angry Hun !

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    Not at all I said building a complete new telelever was overkill and after dissecting those connectors in the upper triple clamp I've been holding my tongue they are well made, but the original poster is having trouble with ground clearance and putting his forks in the stock position will raise the front end back to its ordinary loaded height.Your the one looking for an argument
    To any one who doesn't understand, I like Claude I like my CSM Freedom sidecar, but I don't believe everything anybody in sidecars tells me scepticism is an asset and Dana is also correct perhaps the OP should remove the trail reducer and see if it's even necessary that would also raise the front end and be an easy solution :-)
    #23
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  4. claude

    claude Sidecar Jockey

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    To allow the fron tend to no go down so much with a conventional trail reducer is why we origionally raised the rear on the model we do. Geometry is involved so as not to gain back the trail one wanted to reduce but that is another story.

    In any case my earlier comment was to raise the shock either by a different spring or a spring spacer. This is what Hannigan does with the LTs and such and It works well. We do the same. Some bikes have bridge like the GS and some do not.

    DB what do you mean by holding your tongue? That is not like you LOL. No argument there I was only following your lead when speaking of things being 'good enough'.

    Bottom line Is that an RT or an RS can have the trail reduced and work well.

    Like you too DB LOL.
    #24
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  5. draperg1

    draperg1 PapaBear Supporter

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    WIN_20150415_130452.JPG :clapMine seems to work very well with trail reducer, Hannigan sub frame, and custom Hagon Shocks. I have plenty of clearance and great handling.
    #25
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  6. Ridn3

    Ridn3 Lopsidd

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    Dirty Doc, I attempted to leave the shocks stock but with the reduced trial the fender and fairing were to close. I had hoped that the rebuilt shocks with new springs would solve at least some of the problems. It hasn't and that is why I am looking for other solutions. I have been working on raising the ground clearance and but 3/8" spacers on top of the trail reducer and it helped a little. Right now I not only bottom out on speed bumps, but in parking garages when going from the level part to the down ramp it scrapes. Even when at a crawl pace.

    Everyone, I have looked at the K1200LT shocks. It is difficult to find the length on the stock ones. Looking on ebay, the aftermarket ones seem to be between 3/8" and 1/2" longer. It makes sense that they would be set for heavier duty use as the LT is several hundred lbs heavier. I ordered a used one and will see what the difference is. Going to the Colonial Rally near Williamsburg this weekend so will be sometime next week before I can compare.
    #26
  7. DirtyDR

    DirtyDR Dana Supporter

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    I understood your issue, once you start modifying things it always changes something else. I was simply referring to the fact that I have not changed anything on my suspension, it is all stock. The only concession I have made to sidecar duty is putting a Stroker wheel on the rear so I can run a car tire as the 2,500 miles out of a motorcycle tire was getting ridiculous and expensive. Other than the rear tire and of course the sidecar my GS is factory stock as far as mechanicals go.
    #27
  8. davebig

    davebig Another Angry Hun !

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    [​IMG]
    We'll I'll be damned forks in stock position (look at upper triple clamp) plenty of ground clearance no steering damper 50 k miles of use without any issues, stock length shocks, only problem it had was running over an 8 point buck and bending a fork tube.
    #28
  9. Bobmws

    Bobmws Curmudgeon At Large

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    FWIW, KRS came stock with the front shock 'sport' spring that Hannigan recommended, but it was too soft. I had Klaus build Hyperpro shocks for the bike & a YSS for the car. I did increase front spring preload about 3/8" more than he recommended to gain fairing/fender clearance. Claude's adapter & 15" rear wheel & tire have everything working well. Rear tire is about 1/2 taller than stock bike tire.
    #29
  10. Ridn3

    Ridn3 Lopsidd

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    Ok, Got back from the ride and measured the K1200LT shock against the R1150RT shock. LT shock is aprox 3/8" shorter then RT shock. :( Measured the spring wire diameter using digital caliber. The LT spring and the 400lb spring that had been added to the RT are the same diameter at .40". The stock RT spring is .37. Does anyone know if these diameters correlate with some standard or are there other factors on spring strength when the coils are the same diameter?

    There were two other R1150RT's at the rally. Sitting on them and rocking showed that the front spring on mine may be strong enough. It seems that maybe the rear spring needs to be upgraded higher then the 1100 lb on there. I still have the clearence problem on the front. The friend that that has helped me with all of this is making a 3/4" space to lengthen it, that we are putting onto the LT shock. I will give it a try and see what happens. When we get the front sorted we will then see what we can do with the rear spring.
    #30
  11. claude

    claude Sidecar Jockey

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    [QUOTE="Ridn3, post: 27785837, member: 330395"]Ok, Got back from the ride and measured the K1200LT shock against the R1150RT shock. LT shock is aprox 3/8" shorter then RT shock. :( Measured the spring wire diameter using digital caliber. The LT spring and the 400lb spring that had been added to the RT are the same diameter at .40". The stock RT spring is .37. Does anyone know if these diameters correlate with some standard or are there other factors on spring strength when the coils are the same diameter?

    There were two other R1150RT's at the rally. Sitting on them and rocking showed that the front spring on mine may be strong enough. It seems that maybe the rear spring needs to be upgraded higher then the 1100 lb on there. I still have the clearence problem on the front. The friend that that has helped me with all of this is making a 3/4" space to lengthen it, that we are putting onto the LT shock. I will give it a try and see what happens. When we get the front sorted we will then see what we can do with the rear spring.[/QUOTE]


    Shortening a spring WILL increase the spring rate. Shortening a torsion bar will increase the spring rate. Sounds weird but think of a long bar and trying to bend it versus a short bar and trying to bend it...same idea. So..a shorter spring with the same diameter coils will be stiffer than a longer spring. A stock LT spring with a spring spacer to raise ride height will be stiffer than a stock RT spring with no spacer even though th ecoil diameters are the same.
    #31
  12. claude

    claude Sidecar Jockey

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    With all this being said what one person likes may not satisfy another person. If one feels their outfit is too soft and stiffens it another person can ge to the outfit and take it for a spin only to come back complaining it is a harsh ride. Also....one rider may weigh 100 pounds and another 300 pounds so that can add to the equation of confusion. Everything along these lines is a compromise even though a decent rig may be in the ballpark.
    #32
  13. claude

    claude Sidecar Jockey

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    BTW when you stiffen the front you may find the rear to be satisfactory. Why? Raising the front may transfer enough to the rear to increase sag back there which will increase 'effective' spring rate . Spring rate increases as the spring is compressed. More spring rate may ask for more rebound dampening as a spring that is compressed is doing what? Trying to decompress. I truly think that this will be found to be splitting hairs in this case though. Just food for thought.
    #33
  14. Ridn3

    Ridn3 Lopsidd

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    Claude, Thanks for all the information. On the RT shock, when I had it rebuilt and the new spring added, he installed a shorter spring with about a 2" spacer. So due to the shorter spring, the rate is increased compared to a stock length spring with the same diameter coils? I was wondering why a shorter spring, maybe that explains why it was done that way. BTW, we are not using a spacer under the spring on the LT shock, but are making an extention to mount at the bottom to make the shock effectively 3/4" longer.
    #34
  15. Ridn3

    Ridn3 Lopsidd

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    I have not mounted the spacer to lengthen the front shock yet. The 1st one Draper made was not quite the way we wanted it. We were able to temporarily mount it and it did seem to make a huge difference in ground clearance. He has fabricated a new one and as soon as we both have time I will ride down and we will install it. We did discover that I did not have the preload on the rear shock cranked all the way up and then did crank it up. We took a 400 mile ride Saturady and the rig seemed to handle curves better and had far less wallowing then with the preload only about half way. I was surprised at the difference. Who knows, we may eventually get this thing dialed in right.
    #35
  16. Ridn3

    Ridn3 Lopsidd

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    Went down to Draper's yesterday and we mounted the spacer to the front shock. Made a Hugh difference in ground clearance. With the rear hydraulic preload all the way up and the front spacer I believe that we are very close to having this rig dialed in right. On the 60 mile ride home the rig handled well and all was right with the world. I may not need any additional spring work as I first thought. If I ever decide to replace the front shock I will find one that is an inch longer, but other then that, I am happy with it.
    #36
  17. DRONE

    DRONE Dog Chauffeur

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    I hope you're right about not needing any more spring work. But on my 1150GS rig, when I cranked up the hydraulic preload on the rear shock, I blew out the hydraulic preload adjuster somewhere in the first 5000 miles, which was not rugged enough to handle the pressure. If you find your rig acting different 1000 miles down the road (or 5000) first thing I'd inspect would be that adjuster.

    On my current 1200GS rig, it had Ohlins when I bought it and one of the first things I did was to back off the rear hydraulic preload all the way. Then, when I ordered new shocks from Klaus, I got one without any hydraulic preload adjuster, just an old-style screw. Old vs new --

    [​IMG]

    (And, yes, to anybody who's wondering, I also went from GS length to Adventure length. :bmwrider )
    #37
  18. Ridn3

    Ridn3 Lopsidd

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    Thanks for the tip. Sure hope that I don't experience the same thing, but, now I know what to look for. Was the blow out on the stock shock or the Olins?
    #38
  19. DRONE

    DRONE Dog Chauffeur

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    Ohlins.
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  20. SLACKER

    SLACKER Been here awhile Supporter

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    Getting back to spring rates.....I am in the process of ordering new shocks for my 2001 1150GS DMC Rig. I am planning on getting the longer Adventure length shocks btw. I am having trouble finding what the stock spring rates are on the Showa shocks that came from factory on the bike. Does anyone know what these spring ratings are?
    #40