Tuning suspension for canyon chasing

[bikey]

HI all,

Question about suspension tuning for riding canyon bumpy roads. I've read the Lee Park books and watched some Dave Moss tutorials from him, but most of those tunings seem based on racing?

The suspension profile for racing is way too soft and it's scary on them roads.

Is there any information (anecdotal or not) for tuning suspension for bumpy roads?
TIA

 

[reugene]

First off I think you got a we bit confused as to suspension set up. Smooth flat race tracks require firmer suspension while bumps a dips ( on plain crappie tarmac or out in the dirt) need a soft suspension that will follow the surface rather than just bounce off the high points. Kind of why street bikes have 4 or 5 inches of travel while dirt bikes have like 3 X that much.

 

[budman]

Yup. bikey you have it reversed.
You need suspension to be a bit softer to absorb the bumps and keep the wheel on the ground.

Supposedly my DU CAT has that quick changing electronic crap that adjusts on the fly. Seems to be good.

Compression a little less for the bumps makes sense to me if you have that adjustment available.

 

[stangmx13]

The tuning principles and methods are the same no matter the riding location. Get your spring rate in the ballpark based on some solid recommendations. Tune rebound to control that spring and make the bike feel stable enough. Adjust preload and ride height for small attitude adjustments and for feel during inputs. And adjust compression to settle bumps and control pitch. Change one adjuster at a time and keep changing it until the feeling gets worse. Then back it off to the good setting. Rinse and repeat for all the adjusters like 3x.

In my experience, racing requires slightly more springrate, maybe less rebound damping, and definitely more compression damping. But it’s all very rider and track dependent. A flowing track without hard braking might use softer springs than the street. A hard braking track with elevation will likely use stiffer springs than the street. And damping settings are very personal to the rider. Either way, that’s not “soft”. My race bike always felt wooden and harsh at slow street speeds. There just isn’t enough suspension load on the street to make race tuning feel good.

Dave Moss’s vids aren’t really how people tune at the races. You won’t find a fast race team bouncing the forks to tune rebound or measuring sag. Those are just band-aid techniques to provide some level of service when working with unknown equipment. Race teams use suspension dynos and data acquisition. Or they pay a suspension pro that has already used those things and knows what works well.

 

[Das MotorRad]

Is there any information (anecdotal or not) for tuning suspension for bumpy roads?
TIA

are your fork and shock springs appropriate for your weight? are you at proper sag? are you subconsciously adding input/weight to the bars when riding which may unsettle the bike?

if yes, yes, no, then you are at a good baseline. to make improvements beyond that, you need to feel for yourself what the bike is doing that you do not like. from there, you can make steps in adjusting compression / rebound and high / low speed settings as applicable

 

[reugene]

It would have been of help if you would tell us what motorbike is involved, have you made any suspension upgrades and what are they, what you weigh and what kind of roads are you riding. Have you set the sag and if yes what's it set at likewise does your motorbike have adjustable suspension and where's it set.

I will say that most of the street riders I've come across will tend to set their suspension far harsher than is ever needed. Street bikes must be ready to deal with a far wider range of conditions than a bike used for track days or racing where you know going in what the surfaces are like.

I may not have the spelling correct but the other books you should take a look at are the ones by Andrew Trivett, Paul Thedes.

One last thing keep in mind that Dave Moss is dealing with a stock-pile of unknowns coming from riders who have a wide range experience and ability to really explain what their bike is doing. Because of this all he can really do is talk to the rider and bounce on the suspension to get an idea of what changes to make. Pro race teams bikes are armed with computers that feed the engineers a shit-pot of data points. Not too mention they area dealing with riders who know how they want the bike to feel and are able to explain what going on and what they like and don't like.

 

[nakedape]

Supposedly my DU CAT has that quick changing electronic crap that adjusts on the fly. Seems to be good.

It's adaptive. After a number of miles it senses through speed and a few other factors that you need more or less damping. Also have Ducati. After a number of CYCLES at certain speed it holds there. It's pretty effective.

OP: the SV is a parts bin bike suspension-wise. Go to SV forum and read about how to swap shocks, or better yet, have Wilburs build you one. You might need a US distributor but it's worth it.

You can download a sag setting worksheet and do DIY adjustments that will help, but not as much as a quality shock out back.

 

[Holeshot]

It would have been of help if you would tell us what motorbike is involved, have you made any suspension upgrades and what are they, what you weigh and what kind of roads are you riding. Have you set the sag and if yes what's it set at likewise does your motorbike have adjustable suspension and where's it set.

I'd start here. Stock VS aftermarket shock/ forks is a large difference in adjustment range.

 

[reugene]

The tuning principles and methods are the same no matter the riding location. Get your spring rate in the ballpark based on some solid recommendations. Tune rebound to control that spring and make the bike feel stable enough. Adjust preload and ride height for small attitude adjustments and for feel during inputs. And adjust compression to settle bumps and control pitch. Change one adjuster at a time and keep changing it until the feeling gets worse. Then back it off to the good setting. Rinse and repeat for all the adjusters like 3x.

In my experience, racing requires slightly more springrate, maybe less rebound damping, and definitely more compression damping. But it’s all very rider and track dependent. A flowing track without hard braking might use softer springs than the street. A hard braking track with elevation will likely use stiffer springs than the street. And damping settings are very personal to the rider. Either way, that’s not “soft”. My race bike always felt wooden and harsh at slow street speeds. There just isn’t enough suspension load on the street to make race tuning feel good.

Dave Moss’s vids aren’t really how people tune at the races. You won’t find a fast race team bouncing the forks to tune rebound or measuring sag. Those are just band-aid techniques to provide some level of service when working with unknown equipment. Race teams use suspension dynos and data acquisition. Or they pay a suspension pro that has already used those things and knows what works well.

Just a FYI At the track you do set sag at times because you often change spring rates because of track conditions or it's a place where you're not familiar with so you need to change chassis inclination for one reason or another.

It's adaptive. After a number of miles it senses through speed and a few other factors that you need more or less damping. Also have Ducati. After a number of CYCLES at certain speed it holds there. It's pretty effective.

OP: the SV is a parts bin bike suspension-wise. Go to SV forum and read about how to swap shocks, or better yet, have Wilburs build you one. You might need a US distributor but it's worth it.

You can download a sag setting worksheet and do DIY adjustments that will help, but not as much as a quality shock out back.

On most bikes used for street scratching I've found that as a good starting point the front sag should be between 35 and 40 mm while the rear should be 30 to 35 mm. This gets you good weight on the front when trail braking and turn-in but keeps weight at the rear when coming out of a corner.

 

[stangmx13]

Just a FYI At the track you do set sag at times because you often change spring rates because of track conditions or it's a place where you're not familiar with so you need to change chassis inclination for one reason or another.

Nah, waste of time. You should know the springrate and preload in millimeters or turns. Sag is a result of those two values and those values are concrete. There’s no reason to measure something arbitrary to confirm the real change.

There’s also nothing special about sag. Your bike doesn’t spend much time there. Your suspension will be at a very diff spot when turning in or winding on the throttle.

And it’s a very difficult thing to measure with millimeter accuracy because of friction. A springrate change is ~3%. Since springs are mostly linear, your 35mm sag will also change by that 3%… which is ~1mm and probably smaller than the accuracy of your measurement. You are likely introducing unnecessary errors if you try to match sag after a spring change.

If you want to change the spring to change something about the chassis attitude, just change it. If want to try 2mm extra height with a new spring, just add two turns. Don’t muddy the waters with sag at the races.

My setups on my R6 in MotoAmerica SuperSport were generally:
8.75N/mm & 8-14 turns
9.0 & 6-12 turns
9.25 & 4-10 turns

 

[bikey]

It would have been of help if you would tell us what motorbike is involved, have you made any suspension upgrades and what are they, what you weigh and what kind of roads are you riding. Have you set the sag and if yes what's it set at likewise does your motorbike have adjustable suspension and where's it set.

I will say that most of the street riders I've come across will tend to set their suspension far harsher than is ever needed. Street bikes must be ready to deal with a far wider range of conditions than a bike used for track days or racing where you know going in what the surfaces are like.

I may not have the spelling correct but the other books you should take a look at are the ones by Andrew Trivett, Paul Thedes.

One last thing keep in mind that Dave Moss is dealing with a stock-pile of unknowns coming from riders who have a wide range experience and ability to really explain what their bike is doing. Because of this all he can really do is talk to the rider and bounce on the suspension to get an idea of what changes to make. Pro race teams bikes are armed with computers that feed the engineers a shit-pot of data points. Not too mention they area dealing with riders who know how they want the bike to feel and are able to explain what going on and what they like and don't like.

You're right my bad.

I have an sv650 with standard front forks (preload only) and fz09 rear shock (preload, rebound).

 

[bikey]

Yup. bikey you have it reversed.
You need suspension to be a bit softer to absorb the bumps and keep the wheel on the ground.

Supposedly my DU CAT has that quick changing electronic crap that adjusts on the fly. Seems to be good.

Compression a little less for the bumps makes sense to me if you have that adjustment available.

Ah interesting. I had an SV650 that used to have higher preload. On turns for redwood road the bike would "wobble" less than when I had preload backed out. I know its bad because it risks having a fork bottom out and giving a rougher ride, but on a standard fork with only preload and heavier fork oil it seems to reduce the bouncing? Im not sure how to tell if the bouncing is coming from the front or the back though

 

[nakedape]

You're right my bad.

I have an sv650 with standard front forks (preload only) and fz09 rear shock (preload, rebound).

Is your front spring right for your weight? It could range from .75-.90

Start with this: https://www.superbikeschool.com/emaillinks/pdfs/riderspring.pdf

 

[Holeshot]

You're right my bad.

I have an sv650 with standard front forks (preload only) and fz09 rear shock (preload, rebound).

Not much you can do except springs/ oil weight in the forks. Spring change for the rear. Don't waste money on re-valves, IMO. Likely a fork swap and race worthy shock for best results...but these things can get costly.

 

[reugene]

Nah, waste of time. You should know the springrate and preload in millimeters or turns. Sag is a result of those two values and those values are concrete. There’s no reason to measure something arbitrary to confirm the real change.

There’s also nothing special about sag. Your bike doesn’t spend much time there. Your suspension will be at a very diff spot when turning in or winding on the throttle.

And it’s a very difficult thing to measure with millimeter accuracy because of friction. A springrate change is ~3%. Since springs are mostly linear, your 35mm sag will also change by that 3%… which is ~1mm and probably smaller than the accuracy of your measurement. You are likely introducing unnecessary errors if you try to match sag after a spring change.

If you want to change the spring to change something about the chassis attitude, just change it. If want to try 2mm extra height with a new spring, just add two turns. Don’t muddy the waters with sag at the races.

My setups on my R6 in MotoAmerica SuperSport were generally:
8.75N/mm & 8-14 turns
9.0 & 6-12 turns
9.25 & 4-10 turns

Gosh and after all those races at all those tracks in so many countries it's all been a waste of time. Shit I'm going back to Go-carts where there's no suspension

 

[reugene]

HI all,

Question about suspension tuning for riding canyon bumpy roads. I've read the Lee Park books and watched some Dave Moss tutorials from him, but most of those tunings seem based on racing?

The suspension profile for racing is way too soft and it's scary on them roads.

Is there any information (anecdotal or not) for tuning suspension for bumpy roads?
TIA

By the way something no one has passed on. If I recall the SV came with Showa 41C RSU forks so the good news is that those weres a very popular fork for not only Suzuki but for Honda and I think maybe even some BMW's. Because of this there are all kinds of up-grade bit out there from RaceTech's Gold Valves to Ohlin's full cartridges. it's just a matter of how much you plan on spending. Gold valve kits are like $250.00 and Cartridges range from $750 to $1200.00. If I'm correct about those being Showa we have those same forks on our two Suzuki GS1100 E's that have been built for European Classic Superbike events. Those are being used only because under those rules you can't go for more modern forks like USD ones but you can up-grade from the thin spindly one that came on those machines. There are also some nice rear shocks ( you only really need compression and rebound damping noy high and low speed rebound/compression) but if you can find a shock in your price range that has ride height adjustment I'd consider getting that.

One thing to remember when you are thinking about if the bike is too softly or too stiffly spring is that if the suspension is way too harsh my guy's complain that the bike feels like it's all over the place and they can't get it to corner well where if it's too soft what I'll be hearing is that it's wallowing all over the place. So think of it like if it's way stiff it dances around while if too soft it's like havening flat tires. Hope that helps Mate

 

[stangmx13]

Gosh and after all those races at all those tracks in so many countries it's all been a waste of time. Shit I'm going back to Go-carts where there's no suspension

Ya with how stressful race weekend are, you could have saved some mental energy or used it on something more productive.

There’s always MTB. You gotta measure sag at least once because the air spring recommendations from FOX and Rockshox are nonsense. But once you learn that 120psi is 27% sag and 130psi is 25% sag, you don’t really need to measure it again for that bike/components.

 

[reugene]

Ya with how stressful race weekend are, you could have saved some mental energy or used it on something more productive.

There’s always MTB. You gotta measure sag at least once because the air spring recommendations from FOX and Rockshox are nonsense. But once you learn that 120psi is 27% sag and 130psi is 25% sag, you don’t really need to measure it again for that bike/components.

Yea you are right we we're always messing with things like fuel load (except at places like IOM where you just filled the tank and hopped you could get through full laps not half laps) we should of just always filled the tank and not worried as to sag Never really thought of a race weekend as being stressful. I sort of had my rituals every time the car or bike pitted so I just talked to the rider/driver and then started filling out the session paper I guess there were a lot of things I could of passed on and still had a good finish.

 

[Das MotorRad]

can i just pop in and say that i love how deep the barf pool is?

meaning, a brand-new rider can ask a question and get responses from five different accomplished national and multinational racers. straight from the horse's mouth; no ai hallucinations needed

 

[reugene]

can i just pop in and say that i love how deep the barf pool is?

meaning, a brand-new rider can ask a question and get responses from five different accomplished national and multinational racers. straight from the horse's mouth; no ai hallucinations needed

Not sure where you were going with your post mate. What I really think is I look for every scrap of data I can get on how the vehicle is working and I try and do the same things the same way every time. That goes from always trying to ask the same questions when the vehicle pits to always taking tire temps and pressures at the same spot with the same equipment and as close to the pit entrance as is possible. It's even why I always use nitrogen in tires rather than compressor generated air. I do envy the big time pro teams and the personnel that can gather and usew so many data points but also have enough staff to do something with the data. LOL I do find it a wee bit funny that even with all the modern computers F 1 can't seem to sort out how to make the drivers happy with how the electricity generation under braking systems are dictating how the cars are being driven and where passes can be made. Kind of proves that we should be carful of what we wish for because we just might get it.