Sorting the front end

[greg the pole]

Ok, my slightly modified 2012 bike is great. Rear end is well sorted with a fully adjustable YAC.
Front suspension is still sucking the big one though.

I swapped the front progressive springs to linear springs for my weight, from Stoletec.
I service the forks once a year or 15k which ever comes first (Good clean, and fresh oil)

The bike still bottoms on large bumps, and wallows in fast long corners.

Besides the know suspects:
-Traxxion cartridges $1100 USD. I'll be trying Summitboy's traxxion shod bike soon enough
-Stoletecs fork piston kit, price tbd as I'm talking to Nick now about my issue.
I'm guessing it will be much much cheaper than the cartridges, but a bit fiddly to install, with results not as good as the cartridges (in my uneducated opinion)
-Ohlins..I know Snakebitten has them, but I don't want to know the price
-Racetech does their gold valve kit. I installed it 10 yrs back on my dl1000, wasn't really sure it made a difference. Maybe because it was installed by a mechanically challenged muppet (me-back then)
Someone out there will tell me to simply adjust my stock suspension : Yes, thank you, I have done that already.

thoughts?

 

[yz454]

I went with a .95 spring ,drilled out the compression piston .Finely got off my ass and made a softer booster spring and got ride of that dam plastic spacer . I could not keep fork seals in it, solved that with skf seals . Now I got a nice progressive feel , does not bottom hard and you get more travel in the stroke . If your spring rate is right or close then you the need to adjust oil height for bottoming , and compression clickers to dial in .

 

[Bushyar15]

Wallowing is usually a symptom of compression damping or rebound bound damping needing adjustment, not so much the springs since you get that sorted. Like we used to say in racing you can't tune for all the bumps so you tune to give you the best overall "ride/handling" So if you tune for that big bump, the bike will suck at the the other stuff. Suspension is definitely a compromise.

For the wallowing you're going to have to play with the compression and rebound damping. There are some good articles out there on how to sort that...

 

[Tony Down Under]

This is where I'm at with my 2012 as well....trying to sort the front end. I ride mostly poor bitumen back roads and weigh around 190 lbs. I started with 0.95 kg/mm linear springs and had the compression pistons drilled out and the compression stack modified to suit the new springs. This work was done by a suspension guru. It was an improvement on the OEM set-up but just too stiff for road riding. I had about 4" of unused fork travel and still got a fair bit of jolting and jarring. The OEM rebound damping didn't cope too well with the front end rising too quickly and was overshooting on medium bumps and larger....sometimes in a nasty way. I was getting around with the preload adjusters wound almost all the way out.

I then dropped down a spring rate to 0.90 kg/mm. Softer spring was better. Nicer float and handled smaller bumps better. There was also a reduction in the severity of the jolts and jarring. I'm using more fork travel with about 2 1/2" unused. On the downside as the forks travel deeper into the stroke they rebound pretty quick and overshoot. I'm now having to use way too much rebound damping to slow down the action and pulling in a fair bit of compression damping as well. The has made the fork action too stiff for comfort. Preload is best around the 6th line on the preload adjuster. Rider sag pretty much with zero preload to hard is consistently 50 mm. Not liking this set-up at all!

I've had a conversation with my suspension tuner who is also an Ohlins rep. Apparently Ohlins use a spring rate of 0.80 kg/mm in their fork cartridges. He suggested coming down another spring rate. So I'm thinking of sourcing some 0.80 kg/mm springs and firstly trying a 0.90 in one fork leg and a 0.80 in the other to give me 0.85 kg/mm rate and go down to 0.80 kg/mm if I have to. I think the rebound damping circuit needs some work as well. I don't think I'm too hard to please but the front end is proving to be a challenge to get right! Good luck with your set-up.

It'd be interesting to hear from anyone who has a non OEM set-up that works well without having spent a fortune on drop in cartridges etc.

 

[Checkswrecks]

See if this thread helps:


http://www.yamahasupertenere.com/index.php?topic=13428.msg213063#msg213063

 

[TenereStreets]

Give Ed Sorbo a call. He rebuilt, resprung and revalved my forks. Here's his business http://www.le-suspension.com/fork-services/

 

[yz454]

Tony you need to take out the top spacer , replace it with a softer spring than a 90 or 95 then play with oil wt .

 

[greg the pole]

I'm almost positve I have 90 linear springs. But for the life of me cannot remember what weight oil I put in. i want to say 5w, but it could be 10w.

keep them coming.
I'll check out the links

 

[yz454]

10wt would be pretty heavy and harsh . 5 or 7 or a mix at the most . Get your sag right with springs ,bottoming with oil height and fell with damping adjustments and oil wt .

 

[greg the pole]

Give Ed Sorbo a call. He rebuilt, resprung and revalved my forks. Here's his business http://www.le-suspension.com/fork-services/

would love to, but I'm a mere 2000 miles away, one way. And can't be bothered to ship the forks

 

[greg the pole]

10wt would be pretty heavy and harsh . 5 or 7 or a mix at the most . Get your sag right with springs ,bottoming with oil height and fell with damping adjustments and oil wt .

ill put in 5w next time and actually write down what I used, not when I changed it ::010::
Oil height is as per manual..forgot what it was.

 

[yz454]

But you have oil height adjustment up and down .

 

[greg the pole]

But you have oil height adjustment up and down .

can you elaborate?
I forgot what the height was, but it's right as per manual.
No matter, I'm not far away from a fork piston kit from Penske, 5w oil and happiness ::015::

 

[Firefight911]

can you elaborate?
I forgot what the height was, but it's right as per manual.
No matter, I'm not far away from a fork piston kit from Penske, 5w oil and happiness ::015::

Fork oil height has the effect of adjusting the secondary "spring" in your forks. This spring is air. By raising the fork oil height you increase "spring". Inversely, you reduce "spring" with lower fork oil height, also referred to as air gap.

The air spring has an exponential effect. As the fork is compressed, subsequently compressing the air in the air gap, the effect will rise and then go exponentially vertical in comparison to fork compression. This is a valuable fine tuning tool when determining you point of best suspension action. The point where you want the whole spring, oil, damping rates, air gap to come in the play its best. It's effect is rarely played with by the lay person, just as actually turning the knobs and screws are on modern suspension but its effect, once the other base parameters are set can make for a wonderfully fine tuned suspension.

An example for a real world understanding;

A am running .95 linear springs. As I have improved my skill set in the dirt I have had to adjust for the optimum settings. With my skill set improving I am carrying more speed. Speed increases the force exerted against the fork. This is the classic E=mc squared. Twice the speed equal four times the force. As a result of this increased speed I am blowing through the fork stroke. As such, I need more spring to hold the fork in its middle third of travel better. This is simple to do by swapping my .95 for, say, a 1.00 spring. The problem here is that as the fork moves in to its stroke it is also affected by the air gap which exponentially adds more spring through air gap compression. To offset this I increase air gap (reduce fork oil height) and reduce the air "springs" influence on the overall ride quality. This reduces harshness at greater fork compression use.

 

[Tony Down Under]

See if this thread helps:


http://www.yamahasupertenere.com/index.php?topic=13428.msg213063#msg213063

Thanks. That did help. I've done the same HSC damping mod but I was happy to see the author using 0.8 kg/mm springs. It makes me think I'm heading in the right direction with lighter fork springs.

 

[sander]

This is the classic E=mc squared. Twice the speed equal four times the force. As a result of this increased speed I am blowing through the fork stroke.

E=mc squared has nothing to do with suspension unless you ride a nuclear powered ST close to the speed of light

I think you mean Ek (kinetic energy)=1/2*m (mass)*v(speed) squared.

 

[Mark R.]

The forks are cursed with excessive compression damping, which makes them really harsh. I don't know how he did it, but Rick at Cogent Dynamics really smoothed out my forks, I could not be happier. Yes, I sent the forks to him, but maybe he just needs the guts to perform his magic. I kept the Stoltec straight rate springs I had installed a year earlier.

 

[motoguy]

E=mc squared has nothing to do with suspension unless you ride a nuclear powered ST close to the speed of light

I think you mean Ek (kinetic energy)=1/2*m (mass)*v(speed) squared.

??? umm...ok

 

[yz454]

You will not get a linear feel, with one straight spring rate . You can get close with damping help, but I went a head and made up a second spring to replace the plastic spacer . I did not think i would get these forks to work but there not bad at all now .

 

[Firefight911]

E=mc squared has nothing to do with suspension unless you ride a nuclear powered ST close to the speed of light

I think you mean Ek (kinetic energy)=1/2*m (mass)*v(speed) squared.

See what 120 hours of overtime in less than two weeks will do to a person. Yes, that is the correct formula. Thanks for cleaning it up for us.

http://auto.howstuffworks.com/auto-parts/towing/towing-capacity/information/fpte9.htm

::025:: ::003:: ::008::