2024 KTM PDS Shock Absorber Part 1

[@strifex-suspension-works]

Great explanation. Waiting for the next part.

[@Superdukedotnet]

Another very informative video! Love the explaination of how shock linkages work. Keep'em coming!! Let me know next time you're in LA...I'll throw a shrimp on the barby for ya!

[@andretorben9995]

Terry serviced and revalved all the suspension on my Yamaha R1, also changed some parts in the rear suspension. What a fantastic upgrade the difference was really night and day. If your a bike fan of any sort of bike and really want to improve your bike whether its for racing, comfort or just great feel I highly recommend Shock Treatment. Thanks for your work Terry.

[@flintstoneengineering]

Excellent as usual.

[@zx9b2]

The ZX9R B1 i commute on daily was criticised at its launch in 94' for rear end squat when ridden on track. Apparently the swingarm pivot position was to blame. The swingarm does enter the chain path slightly on mine, but im not expecting to ever have squat issues at road speeds. Interesting content, keep it coming.

[@shocktreatment5495]

I ran the Kawasaki Superbike team back in the late 90's. We had ZX9s up against R1s and GSXRs....knife to a gunfight.... so to speak

[@СергейКулаженко-л3и]

Pure gold... Thank You!

[@shocktreatment5495]

Cheers

[@shaneburesh9173]

Awesome!! Please do a part 2! Great stuff!!

[@shocktreatment5495]

Won't be long

[@shaneburesh9173]

@@shocktreatment5495 do you have any shops in the US that you recommend that would be skilled and you would trust us to send our stuff to here?

[@shocktreatment5495]

I would imagine the US is the same as here. There will be an "Underground" of cranky bike geniuses who are pissed off with consumerism and have retreated to their "Safe Havens" (Backyard sheds, basements etc) to pursue their motorcycle endeavours. If you can hunt one of these out you will be a mile in front compared to the usual shops. What state are you in? I may be able to point you in the right direction.@@shaneburesh9173

[@shaneburesh9173]

@@shocktreatment5495 In Nebraska, but I can ship anywhere! Id say even Australia but the shipping charges and wait would be steep…

[@shocktreatment5495]

Kevin Stillwell in Texas would be a great fit. Jim Metter from Shockzone suspension or Corey from Protune in Ohio. Corey appears to be doing more parts fitting than tuning these days...but a good guy who stands by his customers. @@shaneburesh9173

[@stephenantoniou5695]

Very interesting discussion. I own a 2024 bike with the PDS system, and yes, it fits my style of riding very well. I had a 17 bike with the old system and found it impossible to be good in spite of 1000's of dollars of modifications. I would love to try your PDS system mods sometime using the progressive spring, in all honesty, in my 30+ years of riding and fooling around with this stuff I never found anyone who could tune with a progressive rate spring and make it work. For the bucks, it just traded "good" to happen in a different stroke of the swing arm. Every suspension tuner sold me a progressive spring and I went for it. FYI: I was AA expert in New England.

[@shocktreatment5495]

As mentioned in the video, my interest in the progressive spring is in regards to power delivery / chain torque reactions as opposed to suspension movement. If you were to separate suspension movements from your thoughts and concentrate on how the power develops under acceleration you will be pleasently surprised. There is less squatting and greater stability with the progressive unit.

[@Avelinoferr]

really good!

[@shocktreatment5495]

Thank you! Cheers!

[@randomfootage1488]

awesome video just wondering why the spring rate is so much higher on a pds model ktm then a linkage model ktm thanks

[@shocktreatment5495]

If the shock is mounted further away from the rear axle it will require a harder spring. Closer to the rear axle it will require a softer spring

[@MarkSpencerAZ]

Excellent, thank you!! Sooo, on my 2024 300 XC-W, are you saying I would not benefit from the progressive rate spring if I am just your average trail rider?

[@shocktreatment5495]

It is not so much about suspension. The progression really assists with chain torque reactions. This is where a linkage shines. Any bike that doesn't have a linkage will benefit from a progressive spring.

[@MarkSpencerAZ]

@@shocktreatment5495 Thank you!

[@baldknobby]

Could the chain torque problem be a reason for using a smaller rear spocket on the XCW vs the XC?

[@andretorben9995]

Hi Terry, Sorry to post a second comment but after watching I was thinking about the rear suspension. As you showed there is an element of torque created by the chain when it "pulls" the rear sprocket, causing the swingarm to act against (or compress), the rear shock. But wouldnt there also be an opposing force caused by the rear wheel trying to lift the bike ie; trying to wheelie, which would act in the opposite direction effectively trying to extend the rear shock. Not at all questioning your theories, just trying to understand the dynamics.

[@shocktreatment5495]

(Acceleration) Until there is an equalibrium reached between shock force (accumulating) and perceived bike weight, the rear of the bike will be pulled down and the swingarm pivot will lower. The swingarm angle has potentially moved to a point where it is acting below the effective mass and can now start lifting so long as there is adquate chain force being applied. The level of effect is varied depending on how power is delivered. If you remove the shock and move the swingarm through its arc, you will note that the chain is at its tightest when the centreline of the swingarm is in line with the centreline of the sprocket. Above and below it gets looser. If the swingarm begins the motion in a position where the shortest chain pull is below the static centreline of swingarm and sprocket then you could potentially see a lifting of the rear of the bike. The lower region is a small percentage of the stroke but both scenarios are indeed possible.

[@dcktater7847]

I'm building an electric track bike and all i can have is pds for space issues. I suppose with dirt bike the issue is pro squat due to the low swingarm angle but with track bike it's anti squat. How do you think it changes the situation? I suppose i should go with as small a rear sprocket as possible to minimize the anti squat then so that it's the shock that does the work and chain forces dont meddling. Am i thinkin correctly?

[@shocktreatment5495]

The world is in your hands if you are building the bike from scratch. The relationship between the output shaft and the swingarm pivot is critical. Squat and anti-squat both determine a relationship that is less than ideal but must be considered. Smaller sprockets are better for stability no matter which application you have....road / dirt. One aspect of chain torque that is rarely given much thought is that of back torque. When gearing down for a turn the torque switches to the underside of the chain promoting rear extension which has a dramatic effect on load transfer which if excessive really hampers braking performance. Smaller sprockets are a must here. Most road bike linkages will provide appr 10 - 11% progression. You will be best to plot a leverage curve once the shock is installed as the lean angle will provide a small amount of progression. Once you know what you have you can have a spring wound from there.

[@dcktater7847]

@@shocktreatment5495 Thanks great adivce. Actually I have a way of putting the front sprocket on the swingarm axle itself i think that's the absolute most ideal situation the chain simply just doesnt do anything bad then (not even wobbling). I was thinkin about another solution where it's actually behind the swingarm axle but i'll stick to the on-the-axle solution.. You really know your craft man you are the first who i've seen who isnt bull 💩ing about this pds issue everyone was speaking total nonsense regarding it (and not a small number of people)

[@shocktreatment5495]

@@dcktater7847 Thank You. Sadly.....A lot of people will develop an opinion rather than chase the reality. It's human nature.....it's easy. McDonalds aren't the most successful restaurant because they produce the best food. There is a wonderful underworld within the motorcycle industry where absolute genius's toil away in sheds down the back yard or under their houses for "no where near" the money they deserve just because they love what they do. Meanwhile others sell shiny shit and clean up....Go Figure! Good luck on your quest.

[@shaneburesh9173]

Dying over here Terry! Lol

[@mikebishop6095]

Better fork but worse shock lol hard to keep us happy lol