Setting up suspension

Discussion in 'Technical' started by palexxxx, Jan 5, 2014.

  1. I have been happily riding my Kawasaki Versys for about a year and a half and decided to get something bigger.

    So a couple of weeks ago I picked up my Yamaha TDM900, (sort of like a Versys, but a bit older).

    Anyway, this bike is not new, 2002 model, and for the last six years it has been ridden by a Thai man somewhat smaller in stature to me.

    I am not happy with the suspension as it is and want to adjust it to suit my bulk. Can anyone recommend a workshop in Chiang Mai that can help me, or perhaps one of the forum members with too much time on his hands may be able to help me (I'm prepared to buy the beers).



  2. What type of adjustment do you have front and rear - compression only, compression and rebound, high and low speed compression etc......
    This is the black art part

    Set the rider sag at 25% of the total range - easy
  3. ^ I think it has fully adjustable suspension, but I'm not really sure. I've never done any work on a bike before. The following link might helpfully explain it.

    The Pha Daeng Mansion
  4. Attached Files:

  5. In Chiang Mai I would recommend Chiangmai Motorsport : Chiangmai Motorsport I have had the Suspension set up on My Triumph, CRF and just last Week My Harley. Remarkable Difference in smoothness and the Ride Comfort! All My Bikes are fitted with Ohlins Suspension I might add. The Harley Davidson Front Forks were Built in the States and are Fully Adjustable Cartridge Type the same as in the ZZR1400 Kawasaki. I had Major Dramas trying to get anyone to Set them up correctly and had quite a Number of People have a Go and this Guy just did it all in No Time! Very Impressive!!!

    Attached Files:

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  6. Thanks Dave, and Yes......

    We do Harleys in BKK as well.

    Ohlins for most 1200's including the TTX22 Cartridges and the Piggyback duals w\correct spring rates, and Custom "Legends Suspension" For the really big stuff, up to and including TriGlides! Woot Woot!

    Note: The Legends install requires additional Wiring, routing and know how..... 3 Days minimum required

    TRIGLIDE1. LegendAir2014logo.
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  7. Bradmeister, Great Info thanks, I will pass it on to anyone looking to upgrade their Bikes!
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  8. I recently had quite a bit of work done on the FJR by BDS. Fork rebuild with HyperPro progressive springs and a new rear shock fitted with a HyperPro spring. They also serviced the complete rear end. Removed the swingarm, replaced all the bearings, seals, bushes and overhauled the linkage. One of the best points is they actually know how to set up the suspension so it takes all the guess work out of it. Brad and his team are all very knowledgeable, competent and professional. All work is done according to the service manual and torqued to the correct specification. I will definitely be using them again for any suspension work, highly recommended.
  9. After reading Racetech book about suspension for all types of bikes I've decided to let the Pro's take care of my suspension 'needs'. A very interesting and informativ book about suspension and the physics involved.
    CMS, Chiangmai Motorsport on the corner of 1001/121 has so far done a great job on all bikes I've taken there.

    Screenshot 2017-10-27_10-43-54.
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  10. Oddvar,

    Good idea... as after I read RaceTech material Im not too impressed. Sure, they sell a lot of parts.... yes, they do know they're product most of the time.....

    However, we have found that they go a little on the cheap side with not only shocks, but the lengths and types of springs.

    They typically send less spring and more tube.... kind of like buying fatty flank steak instead of lean sirloin steak.

    Where's the Beef?

    The FJR 1300 was an awesome build. We really enjoyed working with Tubber and his Heavy Cruiser....

    A couple of glitches that our local machine shop bailed us out of.... but overall..... Sweet Action, new linkage, springs, fuids and shock....and ready to rocket at 250kph all day.

    Thanks Tubber

    Attached Files:

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  11. What is wrong with less front spring?
    All modern bikes have short springs and there is no point in having more spring than required by the constraints of travel and coil bind. A shorter spring does the job just fine, and short spring + spacer is lighter than a long spring, notwithstanding the harmonics imposed by a long spring.

    I am not a proponent of the one size fits all approach of a progressive rate front spring. A linear rate, designed for the bike and rider is much more appropriate.
    How can the same spring suit a 50 kg solo rider and a 100 kg rider + 100 kg pillion + all their luggage + a hair dryer? This is the Hyperpro progressive rate approach and logic says it is less than optimal.
    Hyperpro is not alone in this misguided approach, and I am using them for an example simply as they seem a common "upgrade" here in Thailand.
    Take a look at either Racetech or Sonic Spring calculator and compare to the Hyperpro rates to see what I mean.

    BTW good luck in getting the rates from Hyperpro and it was like pulling teeth to get past the marketing BS and to an Engineer who still was very reluctant to tell me what I wanted to know. Once I found out the rate they were using, it was obvious why. I think you will find that a Hyperpro spring is typically both under and oversprung at both ends of the scale, with a generic rate progression that may or may not be suitable. Clearly not the best approach.

    Given the short length, effective angle, load, and if there is a link or not; the rear shock usually must be a progressive rate, but this still needs to be engineered to suit and not simply whatever what the likes of Hyperpro offer up. Ohlins offered 2 or 3 progressive rates for my 3 Ohlins, non-link, rear equipped bikes and in each case one was suitable - if not I have had custom springs made.

    You might want to take a look at Cannon Racecraft in the USA for custom rate springs. I had them make a progressive rear spring at 13.1 - 16 kg/mm over the last 50 mm of range, on a link style rising rate of 9%, for about the same as an inappropriate Hyperpro spring. This allowed me everyday solo riding and riding with panniers with optimal spring rates for both applications
    Sonic will make you any front spring you want and I just had (short) 1.05 kg/mm front springs made for the inverted Cerani fork on my Dyna - the alternative was different springs in each fork to get the desired rate.
  12. Dear forum member Hoghead,

    Great post! Im going to make this brief, but you can write or call, anytime you wish.

    Q: What is a spring? A :A spring is an energy storage device. Ergo: A smaller spring will absord and dissipate less energy.

    Let us clarify what we mean. In as far as a RSU fork with an outdated damper "turkey baster tubes (1970) the correct spring tate witj Longer spings that are dual rate (not to be confused with progressive) and shorter pre load tubes = Plusher Ride.

    RSU forks with less spring and more spacer tubes will yield a shorter stroke. A shorter stroke means you are going to absord less energy and lose suspension travel.

    If Im riding my "sport bike" with approx 17" wheels. @ 60 miles per hour and hit a 1" high right angle bump; How many inches do you suppose the Forks witll go up and down in 1 second? Or the time to recover from the bump?

    When you do that math or stick a Go Pro to your frame and tape the Fork on VDO and play it back in slow motion.... You will have your answer.

    As far as " Modern Bikes" Im not quite sure what you mean..... If you mean RSD forks that employ Stacked Valves for Rebound and compression dampening, as well as cartrdges that are open, closed or pressureized with Nitrogen Gas.......????

    Then its a whole other design and ball game..... Typically, you are right! the springs are smaller but a larger diameter...they are also matched to the manufacturers cartridges or Forks and come in many spring rates and are only Single or Linera rates.

    Let me wrap this post with this info: As far as any springs used in motorcycles for the last 40 years, There are 3 types: Linear, Dual and Progressive

    Linear in you machine is for racing or strest. Yes you will have great feedback and handeling. Im too old now and I dont want to feel anything.

    Dual Rate absorbs the roads inconsistancies and is not used for racing....or I would not recommend it. Its great for touring and carving up the mountains.

    A progressive rate is almost never used up front as load calculations are difficult to calculaye sag and squat the bike. Again, many people and advertisers use this "Buzz word" for DUAL Rate springs.

    Last note: If your happy with Sonic, Cannon, Viking, Eibach, Ohlins, or anyother manufacturer .... Stay with them since you know the quality of the Spring, the spring type, rate and stroke that you like.

    Personally: I like a Ohlins because they are right in our back yard .... but they dont make every shock nor spring for every motorcycle.

    Enjoy the Ride and be seen!

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