2021 401 rear shock

[AltoSax]

I bought a 2021 401 with 1000 miles. I immediately removed 1 pint of the oil ,the level having been topped up while on the side-stand. Taking a hint from this forum, I also changed oil/filter and examined the drained oil for debris-zip!!.
I've since put on 200mi and found the rear suspension to be really harsh given my my weight (160 lbs) and age (74). The front had been set to Comfort Compression and Rebound-good- and the rear shock was set for Comfort Rebound; however, the spring pre-load was all the way backed off to the max - 0 clicks! - yet hitting New England Spring frost heaves nearly popped me up off the seat. Does that seem normal? I'm wondering if the wrong spring was installed or if there is another way to modify for a more compliant ride? BTW my previous ride was a 94 Ducati 900 SP and I had no problem with it's settings.

 

[Jester1971]

Have a measure of the bikes static sag ( just bike, no rider) and rider sag ( bike with you, fully kitted out, helmet boots jacket etc) static should be around 5 to 10mm these bikes are light at the rear. Rider sag should be around 25% of travel so travel for your bike 142mm so 36mm roughly. If the rider sag is more than this then the preload adjuster needs turning till you get close to these figures. Loads of vids online on how to set sag.
Worry about changing the damping after you have the rider sag sorted.
Hope this helps, Jes.

 

[Jester1971]

Sorry, I should have asked, is the spring white? Does the back end bounce when you push the seat down? When the bike is upright without you on it, can you lift the rear up a bit or a lot?
As far as I can tell from many sources for svart-vitpilens and KTM duke 390’ I know of nobody running with no preload on the standard shock.

 

[GeoKrpan]

I bought a 2021 401 with 1000 miles. I immediately removed 1 pint of the oil ,the level having been topped up while on the side-stand. Taking a hint from this forum, I also changed oil/filter and examined the drained oil for debris-zip!!.
I've since put on 200mi and found the rear suspension to be really harsh given my my weight (160 lbs) and age (74). The front had been set to Comfort Compression and Rebound-good- and the rear shock was set for Comfort Rebound; however, the spring pre-load was all the way backed off to the max - 0 clicks! - yet hitting New England Spring frost heaves nearly popped me up off the seat. Does that seem normal? I'm wondering if the wrong spring was installed or if there is another way to modify for a more compliant ride? BTW my previous ride was a 94 Ducati 900 SP and I had no problem with it's settings.

Are you sure it's backed off to the max? Sounds like just the opposite.

I bought my Vit new and it came with the rear preload maxed out.

 

[GeoKrpan]

Sorry, I should have asked, is the spring white? Does the back end bounce when you push the seat down? When the bike is upright without you on it, can you lift the rear up a bit or a lot?
As far as I can tell from many sources for svart-vitpilens and KTM duke 390’ I know of nobody running with no preload on the standard shock.

How do you set the rear preload to 10? There's only 5 notches on the shock.

Comfort, Basic Setting, and Sport all use the stiffest preload adjustment on the rear shock?

Pic of sticker under the seat.
\

 

[Jester1971]

How do you set the rear preload to 10? There's only 5 notches on the shock.

Comfort, Basic Setting, and Sport all use the stiffest preload adjustment on the rear shock?

Pic of sticker under the seat.

\

My rear shock has 10 ramps for preload, mine was on 5 when I bought it new. I set it to 7 to begin with as for me 5 was too soft. I have it on 10 now as at 95kg it was still too soft.
I assume your shock has 10 ramps also as the sticker under the seat says set to 10 for full payload?
If the OP has his shock set to 0 preload the bike will sag a lot, this will be using the softest part of the progressive spring rate just to keep the back end up, his body on top will be using the middle part of the spring rate (which is an unknown rate as WP will not quote it) and the hardest part too. This is why I asked the OP the above questions, if the shock is indeed in its lowest preload setting then I believe increasing it will mean he can use more of its travel. I think the rear of his bike must be sitting really low under his own weight and possibly bottoming out once ridden.
Obviously the OP would need to check the settings and return a post for me to continue to help.
Still waiting…….

 

[GeoKrpan]

My rear shock has 10 ramps for preload, mine was on 5 when I bought it new. I set it to 7 to begin with as for me 5 was too soft. I have it on 10 now as at 95kg it was still too soft.
I assume your shock has 10 ramps also as the sticker under the seat says set to 10 for full payload?
If the OP has his shock set to 0 preload the bike will sag a lot, this will be using the softest part of the progressive spring rate just to keep the back end up, his body on top will be using the middle part of the spring rate (which is an unknown rate as WP will not quote it) and the hardest part too. This is why I asked the OP the above questions, if the shock is indeed in its lowest preload setting then I believe increasing it will mean he can use more of its travel. I think the rear of his bike must be sitting really low under his own weight and possibly bottoming out once ridden.
Obviously the OP would need to check the settings and return a post for me to continue to help.
Still waiting…….

Thank you. I will have to look at the shock again.

 

[AltoSax]

HaHa!-it had not occurred to me that the the frost heave jolt I got was from the rear bottoming-out because the spring had been backed off to 0-clicks by PO. I put it back to 5-clicks and it is ok now. The spring is white. I'll give it some riding time before determining the sags for either solo or passenger loads.
thanks for the replies!

 

[GeoKrpan]

HaHa!-it had not occurred to me that the the frost heave jolt I got was from the rear bottoming-out because the spring had been backed off to 0-clicks by PO. I put it back to 5-clicks and it is ok now. The spring is white. I'll give it some riding time before determining the sags for either solo or passenger loads.
thanks for the replies!

I'm not right very often but this time I was. Glad you figured it out.

 

[GeoKrpan]

My rear shock has 10 ramps for preload, mine was on 5 when I bought it new. I set it to 7 to begin with as for me 5 was too soft. I have it on 10 now as at 95kg it was still too soft.
I assume your shock has 10 ramps also as the sticker under the seat says set to 10 for full payload?
If the OP has his shock set to 0 preload the bike will sag a lot, this will be using the softest part of the progressive spring rate just to keep the back end up, his body on top will be using the middle part of the spring rate (which is an unknown rate as WP will not quote it) and the hardest part too. This is why I asked the OP the above questions, if the shock is indeed in its lowest preload setting then I believe increasing it will mean he can use more of its travel. I think the rear of his bike must be sitting really low under his own weight and possibly bottoming out once ridden.
Obviously the OP would need to check the settings and return a post for me to continue to help.
Still waiting…….

I looked at the shock again, there is indeed 10 notches.

I'm at 5, I'll add 3. I weigh 185lbs, 84kg.

 

[Jester1971]

I have my rebound at 20 for the shock. It is overdamped for sure, I tried at 15 but the rear wheel felt like it was skipping and was going to lose grip mid corner. I kept backing the rebound off until it felt settled. Even on Max preload the damping on mine is next to nothing and still a bit slow.
Just remember if you add preload to adjust the rebound off a bit to get the best from the extra movement your shock will have.
I think a Nitron shock might be my next upgrade.

 

[GeoKrpan]

I have my rebound at 20 for the shock. It is overdamped for sure, I tried at 15 but the rear wheel felt like it was skipping and was going to lose grip mid corner. I kept backing the rebound off until it felt settled. Even on Max preload the damping on mine is next to nothing and still a bit slow.
Just remember if you add preload to adjust the rebound off a bit to get the best from the extra movement your shock will have.
I think a Nitron shock might be my next upgrade.

I'm so glad to get advice from someone as knowledgeable as you.

I will try what you suggest.

 

[GeoKrpan]

I have my rebound at 20 for the shock. It is overdamped for sure, I tried at 15 but the rear wheel felt like it was skipping and was going to lose grip mid corner. I kept backing the rebound off until it felt settled. Even on Max preload the damping on mine is next to nothing and still a bit slow.
Just remember if you add preload to adjust the rebound off a bit to get the best from the extra movement your shock will have.
I think a Nitron shock might be my next upgrade.

I adjusted the rear shock to 10 preload. It's mo' betta'. It actually rides smoother rather than harsher.

I took some familiar curves faster than ever and felt more in control the entire ride.

I also set the fork to 8 clicks compression. And 4 clicks rebound. I think the fork is just the opposite of the shock, underdamped.

I'm contemplating sliding the fork legs up the triple clamps just to experiment. I have a Vit and live where tight, twisty roads abound.

On my ride on Sunday I realized that my helmet doesn't seem to fit me anymore. I guess the lining has compressed because it now sits too low on my head.

I came up with a cheap and easy solution. I folded a small microfiber towel and put it under the lining at the top of the helmet. It works way better than I expected it to, lol.

 

[Jester1971]

@GeoKrpan, Glad you tried it, I think sometimes you can just settle for how something is when it can be much better.
I have actually raised my forks in the clamps, only by 5mm but they now sit on the first ring down from the adjuster cap, it was at the second line. I lowered the forks (which lifts the front end) as with the rear sitting a little higher the front needed raising to match. Just remember if you go the other way and drop the clamps down the fork legs you will make the steering quicker and more twitchy. Try and make as few changes at a time so you know what has affected the handling, also write down your settings so you can go back if you go too far or get lost..
Ride safe, Jes.

 

[GeoKrpan]

@GeoKrpan, Glad you tried it, I think sometimes you can just settle for how something is when it can be much better.
I have actually raised my forks in the clamps, only by 5mm but they now sit on the first ring down from the adjuster cap, it was at the second line. I lowered the forks (which lifts the front end) as with the rear sitting a little higher the front needed raising to match. Just remember if you go the other way and drop the clamps down the fork legs you will make the steering quicker and more twitchy. Try and make as few changes at a time so you know what has affected the handling, also write down your settings so you can go back if you go too far or get lost..
Ride safe, Jes.

More twitchy is what I'm after, lol. Increasing the preload on the rear raises the rear and steepens the front as well.

I saw a vid where the guy lowers the triple clamps by using only the kickstand. I have front and rear lifts but why go through the trouble.

Thank you for your advice.