Soliciting Input - Suspension Upgrades

[mcrider007]

Compression damping needs to be split, or bifurcated, in to two areas. There is hi speed compression and there is lo speed compression.................................................

This is a very good explanation of compression damping (or dampening) but it doesn't fully explain what is happening with the S10's forks. Yamaha in all its wisdom decided to bless the S10 with dual rate springs, one rate which is probably too soft for most riders and another rate that is probably too harsh....and to further complicate the damping, the spring rates change from soft to hard after 75mm, which may be pretty close to where you would expect the high speed compression damping to kick in. Damping is always going to be a compromise and I don't know any way to have really good damping for 2 very different spring rates. If you want to have good damping you are going to have to start with the right spring rate and that rate should be linear.

I haven't seen the high speed compression damping pistons on the S10 but I would be surprised if they actually have stacked shims. Yamaha puts the much cheaper one way spring loaded damping valves on the FJR and I suspect the S10 comes with the same type of high spreed compression damping. Its essentially a relief valve that is either all or nothing and only works good at one suspension speed.

 

[Firefight911]

This is a very good explanation of compression damping (or dampening) but it doesn't fully explain what is happening with the S10's forks. Yamaha in all its wisdom decided to bless the S10 with dual rate springs, one rate which is probably too soft for most riders and another rate that is probably too harsh....and to further complicate the damping, the spring rates change from soft to hard after 75mm, which may be pretty close to where you would expect the high speed compression damping to kick in. Damping is always going to be a compromise and I don't know any way to have really good damping for 2 very different spring rates. If you want to have good damping you are going to have to start with the right spring rate and that rate should be linear.

I haven't seen the high speed compression damping pistons on the S10 but I would be surprised if they actually have stacked shims. Yamaha puts the much cheaper one way spring loaded damping valves on the FJR and I suspect the S10 comes with the same type of high spreed compression damping. Its essentially a relief valve that is either all or nothing and only works good at one suspension speed.

All very true and a good addition to the discussion. As I indicated earlier, this progressive spring certainly could be adding to the dilemma of harshness over teh sharp edged stuff. It certainly helps to explain how we have so much free sag yet can still attain proper rider sag.

Here's a pic of the fork -

 

[JohnB]

A couple additions from what I could do here at the fire house without my competent assistant (AKA, hot wifey) or my log book.

I'm 215 lbs pre dressed weight. I am pretty fully farkled. Search my posts from my farkle thread to see what I have.

Front

Free sag = 40mm
Compression = 14 clicks from max
Rebound = 9 clicks from max
Preload = even to 4th line

With your compression set to fully soft and your rebound set to almost full soft, don't you get a really "bouncy" front end? ::013::

 

[Firefight911]

From one of the other suspension threads, compliments of TigerOne -

Talked to Traxxion, they say the stock spring is .86/1.15.

That right there answers A LOT!!!

A dual rate spring.

VERY soft initial and then quite firm progressive. We don't know the change over point but, regardless, that is a big issue, IMO.

Race Tech calls for their spring to be a .976 which is certainly in line with Traxxion's suggestions.

Tie the spring in with the valving issue and we may be on to a significant source of harshness in our forks.

 

[Firefight911]

I have sent off correspondence to Race tech to solicit their involvement in what we are after in helping our suspension.

We'll see what/if they have anything to say.

 

[mcrider007]

VERY soft initial and then quite firm progressive. We don't know the change over point but, regardless, that is a big issue, IMO.

Race Tech calls for their spring to be a .976 which is certainly in line with Traxxion's suggestions.

Tie the spring in with the valving issue and we may be on to a significant source of harshness in our forks.

I thought that was what I said. My S10 Service Manual lists the spring rates at .85/1.22 KG/mm (pretty chose to Traxxion's numbers) and the change over point at 75mm. My experience, after 3600 miles, is that I am only using 105mm of the available travel so I could certainly go to a much softer spring without any worry about bottoming. How much softer? I currently have 1.0 springs in my Concours14 (which came with 1.2 springs) so I think that would be about right and may also be a pretty good balance with the existing high speed compression damping. If not, the high speed compression damping could be changed with a different weight oil and the low speed compression and rebound damping fine tuned (after the oil change) with the adjusters.

 

[Firefight911]

OK, a little update.......

Had a lengthy, thorough, and fantastic conversation with James at Super Plush today.

We discussed pretty much everything we could without actually being in the same room and having the bike to physically touch. I can tell you, James has some serious knowledge in that brain of his when it comes to suspension, geometry, and the cause and effect of springs, hydraulics, and set up!!!!!

We have put together a great initial game plan for when we get together next week. Looks like we are going to do some riding, get some linear rate springs on board, do some more riding, and then come up with the next best step toward getting my/our Teneres dialed in the suspension department.

I feel VERY good about what just happened and I think I can speak for James in that he is really looking forward to seeing what we have, what he can do, and then provide us all with a great solution to creating a suspension we all can enjoy.

 

[Tremor38]

Re: Re: Soliciting Input - Suspension Upgrades

OK, a little update.......

Had a lengthy, thorough, and fantastic conversation with James at Super Plush today.

We discussed pretty much everything we could without actually being in the same room and having the bike to physically touch. I can tell you, James has some serious knowledge in that brain of his when it comes to suspension, geometry, and the cause and effect of springs, hydraulics, and set up!!!!!

We have put together a great initial game plan for when we get together next week. Looks like we are going to do some riding, get some linear rate springs on board, do some more riding, and then come up with the next best step toward getting my/our Teneres dialed in the suspension department.

I feel VERY good about what just happened and I think I can speak for James in that he is really looking forward to seeing what we have, what he can do, and then provide us all with a great solution to creating a suspension we all can enjoy.

You go girl!! (^〇^)

 

[3putt]

Good info this thread. I have been waiting to post after I get all my numbers from current setup, but decided to post anyway. My last ride on Jan 1st I intended to ease up on the compression (forks) 1 click, but got busy and never did make it.

I am using .95 14" springs and preload spacers cut out of PVC slightly longer than Traxxion recommended so my preload is all the way out, 8 rings to get 30% rider sag. I will get all my numbers later. Pretty nice suspension and I can get nearly all my travel if I hit a ditch or something. I could NOT get full travel before with the OEM springs. I ran with zipties on both forks all the time so I could keep an eye on the travel. Never got over 6".

I am 81 kilos (182 lbs) and you may recall I broke my front fender this summer from very heavy hits offroad at speed due to the highspeed compression. My adjustments at that point was preload completely backed out and compression nearly off also REBOUND nearly off. I believe it may have helped me to have had the rebound screwed in (slower) instead of fast.

The OEM oil in the forks is rated 0 wt.

 

[Tremor38]

I am using .95 14" springs and preload spacers cut out of PVC slightly longer than Traxxion recommended so my preload is all the way out, 8 rings to get 30% rider sag. I will get all my numbers later. Pretty nice suspension and I can get nearly all my travel if I hit a ditch or something.

How would you characterize the high speed damping at this point.

Thanks.

 

[3putt]

It is better than before, but square edge stuff still shows that the highspeed damping needs to be slightly faster. I did not pull the bottom out when I worked on my forks so do not know what kind of valving it has (shims or what).

What i gained with the spring change is full travel (only got about 6" before) and better suspension for my weight. Will have to take it on some rough offroad to get a feel for the setup.

 

[Tremor38]

It is better than before, but square edge stuff still shows that the highspeed damping needs to be slightly faster. I did not pull the bottom out when I worked on my forks so do not know what kind of valving it has (shims or what).

What i gained with the spring change is full travel (only got about 6" before) and better suspension for my weight. Will have to take it on some rough offroad to get a feel for the setup.

Thanks.

 

[Firefight911]

The Latest Update.....

OK, I have had another extensive and quality conversation with James at Super Plush.

We are postponing my trip down next Monday. James has called all over and no one has Super Tenere spec fork springs in stock so he is ordering some in with rates spec'd for me per our conversations and calculations. They have a two to three week lead time as they are built to order. Once they come in we will reschedule and I will go down and we will get to work.

In the interim, can anyone help out with the rear end and come up with some spring specs? I don't have a service manual (going to the dealer this weekend to order it) and we are trying to come up with what our baseline is in the back end. We are going to then make some comparisons to the currently available aftermarket units and come up with a game plan to address the rear as well. Spring rates, free length, stock preload settings/length (not what the owner's manual tells you), and anything you can tell us relating to this. Another important part is what the rising rate is off the linkage, etc. Also, fork oil height and weights.

I'll keep everyone posted as we go ::014:: ::014::

 

[stevepsd]

Here is whats in the US service manual for both front & rear suspension specs.

-steve

 

[Firefight911]

Steve, huge thanks to you!!!!!! This helps set the ball in motion that much sooner to get the resolve we all want.

 

[3putt]

I gave Traxxion (plus they had already worked on another bike) the specs for the fork springs, had to have a custom spring made also. I was surprised to get a 14" instead of the 16.7", but it works very well.

 

[Epping]

Yamaha in all its wisdom decided to bless the S10 with dual rate springs, one rate which is probably too soft for most riders and another rate that is probably too harsh....and to further complicate the damping, the spring rates change from soft to hard after 75mm, which may be pretty close to where you would expect the high speed compression damping to kick in. Damping is always going to be a compromise and I don't know any way to have really good damping for 2 very different spring rates. If you want to have good damping you are going to have to start with the right spring rate and that rate should be linear.

I think there are some misconceptions here. Firstly it is possible the first statement about the soft and hard spring rate is correct in that some riders with a heavy body weight still have not experienced full travel. The misconception I believe is that "hi speed compression damping will kick in" at a particular point in suspension movement. In fact, high speed compression damping can, and we are experiencing harshness, at low amplitude (movement) but hi frequency (speed) at concrete pavement edges and similar. This harshness will be irrespective of the position, or compression, of the front suspension. The statement "that rate should be linear" is a different proposition and for off road, is probably incorrect unless for a dedicated off road machine with very long suspension travel.

 

[Tremor38]

Re: Re: Soliciting Input - Suspension Upgrades

I think there are some misconceptions here. Firstly it is possible the first statement about the soft and hard spring rate is correct in that some riders with a heavy body weight still have not experienced full travel. The misconception I believe is that "hi speed compression damping will kick in" at a particular point in suspension movement. In fact, high speed compression damping can, and we are experiencing harshness, at low amplitude (movement) but hi frequency (speed) at concrete pavement edges and similar. This harshness will be irrespective of the position, or compression, of the front suspension. The statement "that rate should be linear" is a different proposition and for off road, is probably incorrect unless for a dedicated off road machine with very long suspension travel.

+1. With heavy loads during off road riding in particular, progressive rate springs are a good hedge against boken or bent suspension components. Especially when talking about heavy trailies like the GS and S10.

 

[mcrider007]

I think there are some misconceptions here. Firstly it is possible the first statement about the soft and hard spring rate is correct in that some riders with a heavy body weight still have not experienced full travel. The misconception I believe is that "hi speed compression damping will kick in" at a particular point in suspension movement. In fact, high speed compression damping can, and we are experiencing harshness, at low amplitude (movement) but hi frequency (speed) at concrete pavement edges and similar. This harshness will be irrespective of the position, or compression, of the front suspension. The statement "that rate should be linear" is a different proposition and for off road, is probably incorrect unless for a dedicated off road machine with very long suspension travel.

If there are any misconceptions its on how you interpreted my comments. High speed compression is going to kick in when the suspension speed and resulting internal pressures) reach a certain point and if that point happens to be when the spring is transitioning from the soft to hard rate, the harshness is going to be more severe than if the spring rate is linear. The argument of linear vs non-springs is an old one, but I am not aware of any of the recognized suspension experts that recommend non-linear springs for on road applications (can't comment on off road). Its hard enough to achieve consistent damping without adding the complication non-linear springs.

I could see some value in dual rate springs if the soft portion was available for 2/3s of the stroke. In theory you would have a soft (and consistent) ride for the portion of the spring you normally use for riding and a hard spring at the every end of the stroke to prevent bottoming under heavy braking....but I have never seen a dual rate spring that was designed that way.

 

[Firefight911]

Short update on where things sit;

James at Super Plush just emailed today to let me know my fork springs have shipped and are due to his shop on January 25. Once they are there I will be riding down to spend the day working on all things suspension with him.

More to follow in a couple weeks! Stay tuned.

::013::