Suspension Roll Centers

[PMK]

Has anyone altered the handling of their Spyder by adjusting the front suspension roll centers via ride height?

If so, can you share what settings were best and worst.

To keep this topic aware, I fully understand the Spyders front suspension design is a simplistic A Arm setup, without adjustable caster or adjustable camber.

On Spyders with adjustable front spring preload, the chassis roll canter could be altered. With this, a change in camber could result.

While not specifically after a camber change, I would accept it if altering the chassis roll center could improve cornering beyond increasing toe in.

[Cobwebs]

I gave mine three full turns of increased preload from stock and left it at that.Didn't measure anything just enjoyed the taughter feel and quicker response.
Stock front tyres are a whisker funky on outer edges at 12,000klms but that could be my alignment settings.
Wifes bike is stock base model F3 apart from a sway bar so non adjustable shocks (different internals possibly) and feels a little top heavy by comparison.
We search out twisty roads and avoid highways where possible so different goals and riding styles in mind as usual.

[BertRemington]

BajaRon makes a range of suspension improvements so perhaps he could share some insights for the Spyders.

Suspensions are not simple. For instance, I ran my 8-cylinder track Mustang with the stock 1 5/8" front swaybar. At Thunderhill a BMW M3 driver who took turns with me being in front afterwards asked if I knew my inside wheel was lifting in the air. I didn't so I changed to the 4-cylinder 1 1/4" swaybar -- my wheels stayed on the ground and my times were better.

I have two points.

First, stiffer is not better. My preference is to manage spring, compression and rebound rates. However this can be very expensive.

Second, I don't have a deep understanding of 4-bar linkages. They are some sort of intellectual blind spot for me so I have to go by my and others experiences to iterate to a solution. I'm looking forward to other riders findings.

And thanks to PMK for creating this topic.

[2dogs]

I used two rubber donuts, one in each front shock spring. It takes away one spring coil from compressing making the spring stiffer. Along with BajaRon's sway bar, cornering now is like riding on a rail.

[PMK]

BajaRon makes a range of suspension improvements so perhaps he could share some insights for the Spyders.

Suspensions are not simple. For instance, I ran my 8-cylinder track Mustang with the stock 1 5/8" front swaybar. At Thunderhill a BMW M3 driver who took turns with me being in front afterwards asked if I knew my inside wheel was lifting in the air. I didn't so I changed to the 4-cylinder 1 1/4" swaybar -- my wheels stayed on the ground and my times were better.

I have two points.

First, stiffer is not better. My preference is to manage spring, compression and rebound rates. However this can be very expensive.

Second, I don't have a deep understanding of 4-bar linkages. They are some sort of intellectual blind spot for me so I have to go by my and others experiences to iterate to a solution. I'm looking forward to other riders findings.

And thanks to PMK for creating this topic.

Your welcome.
Not needing an anti sway bar or upgraded shocks. Already have aftermarket Fox on the front and a BajaRon anti sway bar with metal links installed.

Merely want to optimize the roll center of the front suspension. With easy access to BUDS and a ROLO laser alignment setup, making readjustments to the front after making changes is easy.

Just curious where these “aggressive” riding style riders have set their front end suspension. I can sort it out, but trying to be a bit thrifty with time and why I asked. So few replies has me considering roll centers are not understood or optimized on the Spyders.

[PMK]

I used two rubber donuts, one in each front shock spring. It takes away one spring coil from compressing making the spring stiffer. Along with BajaRon's sway bar, cornering now is like riding on a rail.

No need for adding biscuits into the springs. Already have performance shocks installed and a BajaRon anti sway bar. Honestly, for our Spyder, adding biscuits would be counterproductive, but thanks for the reply.

You do mention your Spyder is on a rail, with you seated on it, can someone take a photo of the front lower suspension arms asseen from the front and looking straight towards the rear. If so, please post the photo, that would be a good start.

Not sure if you realize it, but increasing preload did alter the roll center. Adding the biscuit increased the springs effective rate, as you mentioned, it made the spring stiffer.

Also, what model and year Spyder?

[spyder01]

Sorry,I cant answer your question PMK but I can tell you that I have adjusters and the sway bar and have tried altering the ride height several ways,up and down and have not been able to tell the difference.I also have tried running more or less air in the rear while on long highway rides and do feel that the bike is ever so slightly more stable when the rear is a little lower,probably due to slightly increased caster.I believe the real problem on the spyder is bump steer which will certainly be the most difficult to solve but would be the most beneficial.Every mod that is currently being done to the front of spyders is in essence stiffening them up which causes the bump steer problem to be decreased but causes a rougher ride.I have read in so many posts,it rides like its on rails but they never mention whether it also rides rougher.I would really like to know just how much rougher they feel.I would love to have less of that darty feel in high speed sweepers but just how much rougher would it get?My bike already got noticeably stiffer when I put on the swaybar so I wouldnt want it to get any worse.I realize some folks dont care much about comfort they just want the train ride.

[bikerchris1270]

Has anyone altered the handling of their Spyder by adjusting the front suspension roll centers via ride height?

If so, can you share what settings were best and worst.

To keep this topic aware, I fully understand the Spyders front suspension design is a simplistic A Arm setup, without adjustable caster or adjustable camber.

On Spyders with adjustable front spring preload, the chassis roll canter could be altered. With this, a change in camber could result.

While not specifically after a camber change, I would accept it if altering the chassis roll center could improve cornering beyond increasing toe in.

I actually had to research “Suspension Roll” to educate myself on the topic. I learned something today. So... the next time I fall off taking a tight turn too fast I’ll blame it on Suspension Roll.

[PMK]

Sorry,I cant answer your question PMK but I can tell you that I have adjusters and the sway bar and have tried altering the ride height several ways,up and down and have not been able to tell the difference.I also have tried running more or less air in the rear while on long highway rides and do feel that the bike is ever so slightly more stable when the rear is a little lower,probably due to slightly increased caster.I believe the real problem on the spyder is bump steer which will certainly be the most difficult to solve but would be the most beneficial.Every mod that is currently being done to the front of spyders is in essence stiffening them up which causes the bump steer problem to be decreased but causes a rougher ride.I have read in so many posts,it rides like its on rails but they never mention whether it also rides rougher.I would really like to know just how much rougher they feel.I would love to have less of that darty feel in high speed sweepers but just how much rougher would it get?My bike already got noticeably stiffer when I put on the swaybar so I wouldnt want it to get any worse.I realize some folks dont care much about comfort they just want the train ride.

As time permits, seems I need to do some testing to determine the best values for us on our Spyder. Already it handles very well, and has that planted feel. Yes the front Fox Shocks did firm it up slightly, and the BajaRon anti sway bar increased chassis roll stiffness. Bump steer is always a concern, and will not be entirely resolved without a major redesign which is not happening by me.

I have an idea of where I will begin in making change to the chassis setup, first though I need to get my current settings recorded as a baseline to return to if needed.

Straight line stability has not been an issue since I aligned it myself in 2014 and several times thereafter. The immediate evasive type handling is currently proven and does not upset the chassis enough to be a concern. This is likely based on spring rates and increased anti sway bar stiffness. Only on rare occasions does the Spyder even begin to cut hard to the inside. Overall though, I think the machine has more to offer up. Maybe I should remove the spring from one of my spare Fox Shocks and measure bump steer and plot it throughout the suspension travel, while turned in and turned out.

Consider though that if running automotive front tires, it is very likely increased roll stiffness is needed based on increased grip.

[PMK]

I actually had to research “Suspension Roll” to educate myself on the topic. I learned something today. So... the next time I fall off taking a tight turn too fast I’ll blame it on Suspension Roll.

Educate yourself to not fall off...

[BertRemington]

spyder01 is pointing in the same direction as my thinking and experience: spring, compression and rebound rates.

The current cornering performance is adequate but the "dartiness" is disconcerting. Replacing the stock Kendas (year 2015) with Vredestein Quatrac 5 | 165/60R15 on the fronts made a big improvement. I haven't experimented with tire pressures yet. A few days later I replaced the stock Kenda (year 2018) with Uniroyal Tiger Paw Touring | 215/60R15 but my butt isn't sensitive enough to determine if there was any change.

RaceTech is up the road from me so when my bank balance recovers I'll pay them a visit. I'm thinking front shocks with softer springs, a bit higher compression rate, and a bit lower rebound rate. They might also have something to say about a bump steer mitigation. There were a number of solutions for Mustangs so maybe something similar can be fabricated for the Spyder.

Meanwhile I'm going to adjust the toe-in as PMK advised.

[PMK]

spyder01 is pointing in the same direction as my thinking and experience: spring, compression and rebound rates.

The current cornering performance is adequate but the "dartiness" is disconcerting. Replacing the stock Kendas (year 2015) with Vredestein Quatrac 5 | 165/60R15 on the fronts made a big improvement. I haven't experimented with tire pressures yet. A few days later I replaced the stock Kenda (year 2018) with Uniroyal Tiger Paw Touring | 215/60R15 but my butt isn't sensitive enough to determine if there was any change.

RaceTech is up the road from me so when my bank balance recovers I'll pay them a visit. I'm thinking front shocks with softer springs, a bit higher compression rate, and a bit lower rebound rate. They might also have something to say about a bump steer mitigation. There were a number of solutions for Mustangs so maybe something similar can be fabricated for the Spyder.

Meanwhile I'm going to adjust the toe-in as PMK advised.

As a person with hands on suspension tuning for the past 45 years, you might get the recommendation to go with your request by Paul Thede of Race Tech, but honestly I doubt it. In simple terms, springs support and damping controls. Off road typically the better setup is adequate spring with minimal preload, and damping to suit. On road most times it is focused on the heavier machine and requires an adequate spring, running a lot of preload, and damping to suit. Overall, as for clickers, off road they make great sense, as the terrain can vary a lot. On road, but not on the track, a good setup of internal valving will not require external clickers, there simlpy is minimal need to make changes once set.

[bikerchris1270]

Educate yourself to not fall off...

Velcro

[BertRemington]

PMK -- my experiences with urethane (and sometimes Delrin) bushings have been good, both for reduced deformation and friction. The Spyder A-arm bushings appear to be the standard metal-enclosed rubber. What is your assessment of performance improvement (specifically "dartiness") for replacing them with Energy Suspension, Prothane, etc bushings? Thanks.
A-arm Bushing.jpg

[DougE]

When I installed the M2 shocks The directions recommended 4.25” to 4.5”. I set it right in the middle, but never tried any other settings to see if it made any difference.

[PMK]

When I installed the M2 shocks The directions recommended 4.25” to 4.5”. I set it right in the middle, but never tried any other settings to see if it made any difference.

4.25” to 4.5” measured where, from ground to nose of Spyder?

[PMK]

PMK -- my experiences with urethane (and sometimes Delrin) bushings have been good, both for reduced deformation and friction. The Spyder A-arm bushings appear to be the standard metal-enclosed rubber. What is your assessment of performance improvement (specifically "dartiness") for replacing them with Energy Suspension, Prothane, etc bushings? Thanks.
A-arm Bushing.jpg

Have not swapped the oem bushings for urethane as of yet. Honestly, its a Spyder RTS, so it will take more than swapping bushings to lose the family tourer heritage it has. I am sure it could help, but the gain is likely minimal as on the RT the A Arms and chassis is kind of a noodle.

[Cobwebs]

Of course don't forget you can always do it with lower profile tyres if available.

[troop]

spyder01 is pointing in the same direction as my thinking and experience: spring, compression and rebound rates.

The current cornering performance is adequate but the "dartiness" is disconcerting. Replacing the stock Kendas (year 2015) with Vredestein Quatrac 5 | 165/60R15 on the fronts made a big improvement. I haven't experimented with tire pressures yet. A few days later I replaced the stock Kenda (year 2018) with Uniroyal Tiger Paw Touring | 215/60R15 but my butt isn't sensitive enough to determine if there was any change.

RaceTech is up the road from me so when my bank balance recovers I'll pay them a visit. I'm thinking front shocks with softer springs, a bit higher compression rate, and a bit lower rebound rate. They might also have something to say about a bump steer mitigation. There were a number of solutions for Mustangs so maybe something similar can be fabricated for the Spyder.

Meanwhile I'm going to adjust the toe-in as PMK advised.

I was inquiring back/forth a bit with Jeff Zeliadt from Race Tech. For my particulars on my F3S, his response for spring rates were:
"Probably in the range of 8.5Kg/mm front and 9.8Kg/mm rear." The Podium shocks on the front of my 2019 F3S are 86lb/in. The 8.5kg/mm equates to about 476lb/in. Those rates are quite a bit stiffer than the OEM rates.

[DougE]

4.25” to 4.5” from the ground to the bottom of the frunk. DC7D6414-2246-4F16-9EC6-5AD300143377.jpg

[DougE]

Sorry the picture is upside down. I don’t know how to fix it.

[PMK]

Of course don't forget you can always do it with lower profile tyres if available.

While this method does lower the roll center height, it does not optimize the geometry of the suspension. Will not work for what I plan to accomplish.

[PMK]

I was inquiring back/forth a bit with Jeff Zeliadt from Race Tech. For my particulars on my F3S, his response for spring rates were:
"Probably in the range of 8.5Kg/mm front and 9.8Kg/mm rear." The Podium shocks on the front of my 2019 F3S are 86lb/in. The 8.5kg/mm equates to about 476lb/in. Those rates are quite a bit stiffer than the OEM rates.

Might want to check your math, pretty sure you missed a decimal point...seriously though, that is huge difference if accurate.