Suspension setup for the occasional offroad

[chris94]

I've put over 10.000 kms on my Tenere 700 and love almost every aspect of it, but I just cannot get the suspension to perfection with the stock adjustments. I'm about 95 kgs with gear and I've got a new RallyRaid 90 Nm rear spring on order as I'm currently running 24 clicks on the preload to get 25mm static and 60mm rider sag. My issue is that after 100 kms on tarmac my bottom and lower back can't stand the ride, every little imperfection in the road is sent up my spine and shaking my arms. There's not a lot of gravel roads where I live, but when I head over the the TET trails in my country (Norway) I like to go quite fast on the loose gravel and want the bike to behave reasonably nice and safe. I rarely do any hard or complicated sections, but when I do I go slow. 

What would my best options be for getting my desired comfort and damping from the stock forks and shock? Will the new rear spring set me up far enough in the stroke to give me more comfort? A local suspension guru suggested a full KTech revalve, but that's gonna set me back about 1500 euros... 

[Stevoh]

I have pretty much the same K tech setup, I'm almost the same weight, off road and riding hard it's awesome, but unless your pushing it and hitting things hard it tends to deflect, interested to see what settings you come up with, the last big ride we did fully loaded I was feeling like the front wanted to wash out and needed to steer with the rear wheel on dirt roads, could be the front tyre but I'm on a mission to fix and have put settings front and back to standard as per service manual and will go from there.

Also Allen M is correct, the guy who did my upgrade wasn't interested in other variables for the setup.

Edited October 10, 2022 by Stevoh

[Hollybrook]

@Stevoh if you are on the stock front tire, I have found it to be poor offroad.  To get adequate grip I have to be way over the tank and bars before it stops washing out. I don't have any experience with other tires yet but will be putting a Motoz dual venture on next along with a TKC-80 on the rear. 

[Svrider]

On 10/10/2021 at 10:20 AM, chris94 said:

So I sold the RR spring as soon as I got it, and went for a full KTech upgrade at a local suspension shop instead

 

I went with a 75 Nm spring in the rear and new piston assembly in the shock. The spring has a lower rate than the RallyRaid springs, as the KTech spring is a bit longer. I'm running 2 clicks in on preload, 15 clicks out on compression and 13 out on rebound, and what a difference! The bike sits a little higher and feels much more solid, while at the same time being more comfortable as I'm sitting higher in the stroke.

 

I got a front fork cartridge ORDS system (expensive..) with 6.6 Nm springs, and this totally transformed the bike. Currently at 3 turns in on preload, 15 out on comp and 12 out on rebound (comp and rebound goes to 32 clicks). The nose dive is completely gone, and the bike is even more confidence inspiring and inviting to an amateur like myself. I've ridden a few dirtbikes in my life, and sitting down on the saddle for the first time after these upgrades immediately reminded me of those proper offroad bikes.

 

My only issue so far is that the front forks doesn't want to "give" on the micro bumps on tarmac. Its not to the point where its exhausting, just really annoying and feels like it should be able to absorb these bumps. Its like the forks are stuck in the initial stroke instead of giving in on the 0.2 inches necessary and instead sends it right up the handlebars, and no adjustment seems to alter this. It might just be friction in the seals and completely normal, but I'll have the suspension shop check it out in a week or so.

 

24 clicks on the stock spring  At about 95kg fully geared I'm 2 clicks in on the 75 Nm spring from KTech, which to my knowledge can be compared to the 90 Nm from RallyRaid, so seems about right.

So I went with the Rally Raid open cartridge inserts, and went middle adjustment on comp and rebound only to find the same problem on the road. Would not absorb anything and felt like it was constantly bouncing. After a few adjustments, no comp at all, and 5 clicks from full soft on rebound took the bounce out about 80%. Off road was a bit different, I went back to mid adjustment on comp(9 clicks from full hard) and rebound still at 5 from full soft felt pretty good with quite a bit of control at decent clip over pretty rocky terrain.

[e010584]

Needing similar advice on ktech springs initially before revalving.  Rider weight is 172 lbs, riding primarily off road, intermediate rider.  Ktech doesn't seem to be very specific beyond 6.3*, 6.6 or 6.9 N fork springs (*suggested) and 75, 80, 85, 90 or 95 N rear spring (no specific suggestion.  My guess would be a 6.3 N front spring and 85 N rear spring based on nothing more than Ktech's suggestion and other threads indicating a 90 N rear would be about right, but backing off a bit because the Ktech spring is a bit longer (than RR) having an effective preload.  The end goal is to have no preload dialed in at the rear for normal rider sag, such that adding luggage will add preload.  As it turns out, there is a set of 6.6 N fork springs readily available locally that may be a bit stiff, but perhaps appropriate for riding primarily off road.

 

Anybody have any experience to lend into making a final decision here.

[e010584]

On 10/4/2022 at 3:37 PM, Henchman said:

I'm also looking at a front and rear spring/shock upgrade..perhaps K-tech and found some good info here on this thread, but having trouble trying to determine what is my best spring rate choice for my 165lbs/75k naked weight. Loaded up/rider weight for ADV riding i'm guessing I'm another 50lbs so total rider weight around 215lbs/97k

 

I see here in this thread that @Poacher and @chris94 also both have a rider weight between 95-100k and use 2-3 clicks of preload.  

But what's confusing is that Poacher uses a 90nm Ktech and Chris a 75nm Ktech...which are radically different spring rates. Per the K-tech, the 75n is for 200-220lbs and the 90n for 265-285.  

 

Per my weight I'd  fall into the 75nm, but I read that it is recommended to have the least amount of preload a possible to keep the spring in it's upper part of the stroke, where it's the softest.  But this of course requires a stiffer spring and why most upsize their springs.  

 

Anyhow...if anybody can offer any advice to help me make the right decision I'd really appreciate it.

 

Thanks!

 

 

 

Didn't see a definitive answer on this one as there is seemingly a huge difference between a 75 and 90 Nm rear spring.  I would think the 75 Nm would need more preload and be less optimal as a result, but think 85 Nm likely about right for my 172 lb w/o gear weight.

[Henchman]

2 hours ago, e010584 said:

Didn't see a definitive answer on this one as there is seemingly a huge difference between a 75 and 90 Nm rear spring.  I would think the 75 Nm would need more preload and be less optimal as a result, but think 85 Nm likely about right for my 172 lb w/o gear weight.

I'm 165lbs and went with the ktech 75N and 6.3 and like it. I needed zero clicks w/ no gear so good there...and gave it 4 clicks on my last adv ride w/ around 50lbs and it seemed good but didn't measure.  When needing to push it hard, like uphill rocky terrain, I did lightly bottom it out when I'd hit something TOO hard but overall I like the small bump compliance better and would rather have it a bit too soft than hard. Perhaps I need to play with compression but have yet to do this bc I feel it's a good compromise. I have ridden my friends T7 with a 6.6 front and unloaded on the road and I do not care for the initial stiffness of the front end.  

It's a tough call as it's always a compromise both ways.

[Windblown]

4 hours ago, e010584 said:

Needing similar advice on ktech springs initially before revalving.  Rider weight is 172 lbs, riding primarily off road, intermediate rider.  Ktech doesn't seem to be very specific beyond 6.3*, 6.6 or 6.9 N fork springs (*suggested) and 75, 80, 85, 90 or 95 N rear spring (no specific suggestion.  My guess would be a 6.3 N front spring and 85 N rear spring based on nothing more than Ktech's suggestion and other threads indicating a 90 N rear would be about right, but backing off a bit because the Ktech spring is a bit longer (than RR) having an effective preload.  The end goal is to have no preload dialed in at the rear for normal rider sag, such that adding luggage will add preload.  As it turns out, there is a set of 6.6 N fork springs readily available locally that may be a bit stiff, but perhaps appropriate for riding primarily off road.

 

Anybody have any experience to lend into making a final decision here.

 

I weigh 180-190 in street clothes.  My home turf is the mountains along the East Coast in the USA.  I ride a mix of pavement to fairly rough goat trails. I wanted a set up for good control and comfort up to as moderate pace, no big jumps on the agenda. My goal was a set-up tuned for maximum off-road performance when carrying very little if any additional load. My bike weight as set up is (221f+235 r = 456lbs total with full tank)

 

Forks - 6.3N    160~195lb rider (weight range per Ktech)

Shock - 75N    200~220lb rider (weight range per Ktech)

 

This set up seems to work pretty well and rider sag is in the right ball park - 

 

Rider sag using moto-tool digital gauge:

Forks - 62mm

Shock - 62mm zero w/zero preload, 56mm w/7 turns of preload (which I actually prefer).

 

The springs are pretty spot on for me.   I've noticed a tendency for ADV riders to go one rate heavy (or more) on spring rates when they opt to change things up.  The only reason I can figure is they do this because they plan to run heavily loaded most of the time and want best performance when loaded.  For me I want the bike performing best when either unloaded or lightly loaded as that's when I am most likely to be asking the most out of the suspension.  I chill out when I'm traveling long distance with 60+lbs of gear strapped on the bike so that's not where I need the suspension to be at it's best.

 

 

Edited June 1, 2023 by Windblown

[e010584]

Certainly seems more consistent inputs from the two similar weight responses resulting in same spring rates.  I was still expecting a higher rear spring rate based on other inputs in the same weight class running more like 90 nm on RR springs.  As previously mentioned the ktech is a longer spring, effectively having a higher preload at 0 clicks,  but I was still expecting closer spring rates to RR.  Admittedly, I'm also inclined to go a bit stiffer given my off road bias 

Edited June 2, 2023 by e010584

[Windblown]

9 hours ago, e010584 said:

Certainly seems more consistent inputs from the two similar weight responses resulting in same spring rates.  I was still expecting a higher rear spring rate based on other inputs in the same weight class running more like 90 nm on RR springs.  As previously mentioned the ktech is a longer spring, effectively having a higher preload at 0 clicks,  but I was still expecting closer spring rates to RR.  Admittedly, I'm also inclined to go a bit stiffer given my off road bias 

 

Probably diving into stuff everyone knows but....  Spring rates can certainly vary by one step or so depending on the bike/rider and the terrain.  Furthermore sag which plays a vital role regardless of spring rate can be set into the proper range with a pretty wide range of spring rates for a given bike/rider combo with by tweaking preload.  Less preload allows a higher spring rate to be used and more preload allows a lower spring rate to be used to achieve the same sag. 

 

So what's the difference? The difference is what happens as the suspension is compressed or extended from that single point of equilibrium (sag).   A higher spring rate with less preload is going to be softer above the rider sag point and increasingly stiffer below that point compared to a lower spring rate with more preload dialed in to achieve the same rider sag.

 

What does this mean (with all other things being equal)?

 

Higher spring rates resist bottoming better. However it also means it is less complaint when the suspension gets compressed by an outside force (rocks, speed bumps, g-outs, hitting jump face, etc).   When the suspension is extended above the sag point it will apply less force than a spring with a lower rate. In the case of fork springs this can be an asset when "floating the front" under acceleration while climbing a rocky hill (for example) as it makes the front MORE complaint above the sag point. While less plush a higher spring rate can provide more "feedback".

 

Lower spring rates: Better compliance as compressed generally translates into better traction as well as a more "plush" feel.  It provides more downward force when extended past the sag point compared to a higher rate spring. This can help drive the rear tire down quicker to get back in contact with the ground faster as reacts to terrain (again, if all other things are equal).  Softer springs can feel more vague.

 

Now before the experts roast me...

I realize it's not all as simple as stated since valving, hydraulic stops, oil height, etc all play a role and can all be modded to work better in conjunction with either higher or lower spring rates. In the end if it was as simple as plugging numbers into an equation and coming up with the perfect valving/spring/oil height/sag combo there would be no need for discussion and every suspension expert would use the exact same formula for all those variables and it would online for anyone to plug numbers into.

 

That's my story, and I'm sticking to it.

 

 

 

Edited June 2, 2023 by Windblown

[e010584]

23 hours ago, Windblown said:

 

Probably diving into stuff everyone knows but....  Spring rates can certainly vary by one step or so depending on the bike/rider and the terrain.  Furthermore sag which plays a vital role regardless of spring rate can be set into the proper range with a pretty wide range of spring rates for a given bike/rider combo with by tweaking preload.  Less preload allows a higher spring rate to be used and more preload allows a lower spring rate to be used to achieve the same sag. 

 

So what's the difference? The difference is what happens as the suspension is compressed or extended from that single point of equilibrium (sag).   A higher spring rate with less preload is going to be softer above the rider sag point and increasingly stiffer below that point compared to a lower spring rate with more preload dialed in to achieve the same rider sag.

 

What does this mean (with all other things being equal)?

 

Higher spring rates resist bottoming better. However it also means it is less complaint when the suspension gets compressed by an outside force (rocks, speed bumps, g-outs, hitting jump face, etc).   When the suspension is extended above the sag point it will apply less force than a spring with a lower rate. In the case of fork springs this can be an asset when "floating the front" under acceleration while climbing a rocky hill (for example) as it makes the front MORE complaint above the sag point. While less plush a higher spring rate can provide more "feedback".

 

Lower spring rates: Better compliance as compressed generally translates into better traction as well as a more "plush" feel.  It provides more downward force when extended past the sag point compared to a higher rate spring. This can help drive the rear tire down quicker to get back in contact with the ground faster as reacts to terrain (again, if all other things are equal).  Softer springs can feel more vague.

 

Now before the experts roast me...

I realize it's not all as simple as stated since valving, hydraulic stops, oil height, etc all play a role and can all be modded to work better in conjunction with either higher or lower spring rates. In the end if it was as simple as plugging numbers into an equation and coming up with the perfect valving/spring/oil height/sag combo there would be no need for discussion and every suspension expert would use the exact same formula for all those variables and it would online for anyone to plug numbers into.

 

That's my story, and I'm sticking to it.

 

 

 

Good input regardless.  As you mentioned, preload can be used to adjust the suspension performance and, as adventure bikes, weight with and without luggage is one of the biggest variables.  As such, despite everything being a compromise, it would seem prudent to select a spring rate that provides ideal rider sag without luggage or preload in order to have the most preload adjustability for luggage (or passenger) variation.

[e010584]

On 6/1/2023 at 11:37 AM, Windblown said:

 

I weigh 180-190 in street clothes.  My home turf is the mountains along the East Coast in the USA.  I ride a mix of pavement to fairly rough goat trails. I wanted a set up for good control and comfort up to as moderate pace, no big jumps on the agenda. My goal was a set-up tuned for maximum off-road performance when carrying very little if any additional load. My bike weight as set up is (221f+235 r = 456lbs total with full tank)

 

Forks - 6.3N    160~195lb rider (weight range per Ktech)

Shock - 75N    200~220lb rider (weight range per Ktech)

 

This set up seems to work pretty well and rider sag is in the right ball park - 

 

Rider sag using moto-tool digital gauge:

Forks - 62mm

Shock - 62mm zero w/zero preload, 56mm w/7 turns of preload (which I actually prefer).

 

The springs are pretty spot on for me.   I've noticed a tendency for ADV riders to go one rate heavy (or more) on spring rates when they opt to change things up.  The only reason I can figure is they do this because they plan to run heavily loaded most of the time and want best performance when loaded.  For me I want the bike performing best when either unloaded or lightly loaded as that's when I am most likely to be asking the most out of the suspension.  I chill out when I'm traveling long distance with 60+lbs of gear strapped on the bike so that's not where I need the suspension to be at it's best.

 

 

Went with the 85 Nm rear spring and 6.6Nm fork springs and thought it might be a bit stiff based on this and other inputs, but came in at 60mm rider sag with no preload, which was my goal.  Despite indications that the Ktech rear spring was longer than the stock spring, I didn't notice any appreciable difference.  Now I need to spend some time with the clickers, but it feels noticeably better already with it being sprung for my weight.  Revalving likely needed in the end, but willing to go to the limits of the clickers first and consider different weight oil in the forks.