This is fantastic, thank you for providing not only great technical information but also reasoning behind the changes. Really helps to understand the cause/effect!

Ktm 1290 is a beast

Goldmine! Thanks a lot for these videos! Really humble in the explanations as well!

Anti-squat! Niceeeee 💪🏽💣

Fantastic videos, I’ve done a fair amount of track days on mine now (stock) and feel I’m getting to a point where doing some of these tips will now benefit greatly! With the change of sprockets 15/40 how many chain links are used? 114? Do you know what the top speeds were on this set up? I ask as a fair amount of tracks near me have some long straights or higher speed sections.

Dude, these are some of the best bike-specific videos by a racer on the net. We all appreciate the time you take,,,.... Where do I get the belly pan and front light fairing to get through the Tech inspection?

@superduked33

Жыл бұрын

I had to make all our stuff cause it was Covid but there’s a place in France I think called S2 Concepts, they makes everything you need now. www.s2-concept.com/en/18371-plaque-numero-avant-ktm-1290.html

@MasterBlasterSr

Жыл бұрын

@@superduked33 Eric thanks a lot man, I'm planning to race a gen 3 this year in the CMRA.

Interesting video, I'm watching this as a 1290 SDGT owner. That bike has a lot to it that seems to already be in the right direction for handling, namely a good chunk more weight on the front and the electronically controlled rear shock. This electronically prevents squat by stiffening up low speed compression under acceleration. I still think this is a stopgap method, but I plan on springing the bike to my weight with a progressive shock spring, whilst keeping the original electronic hardware if possible as it works really well. With regards to direct mount shocks, you don't necessarily need a linkage to achieve progressiveness but it certainly makes it easier to make adjustments. I've been thinking of possibilities, such as spacer or relocation kit to make the shock more upright. in this bike's case since the swingarm moves in an arc, but the shock is at an angle leaning forward, initially the swingarm has a hard time to push against the sideways shock, as it moves through the stroke though, the shock gets progressively closer to being tangential to the motion of the swingarm, this means the force acting on the shock is now more and more direct, causing less force to be needed to compress it, as you explained. Now if you can make the shock bit more vertical, you can achieve the opposite effect. If throughout the travel the shock "leans back" compared to the travel, you can achieve progressiveness without a linkage or spring. I wonder if it would be possible to relocate the top mount of the shock further rearward, considering there appears to be some real estate. You could also move it forward on the swingarm but you have to be careful with bending moments and total travel, the closer the shock is to the pivot, the more travel you have at the wheel. Not too sure about secure mounting down there either, even though there definitely is space.

@superduked33

Жыл бұрын

I tried hiring a guy to design a link for the gen2. Even bought links from a Ducati to use in our Frankenstein design. Never happened though. One of those challenges that ended up only existing in our thoughts and theories. My ultimate solution was using a stiffer spring, and controlling the travel to avoid that deep part where the shock would collapse. In the end that bike ripped around a racetrack. I still miss some parts of it. In fact I will be riding that bike again this coming Monday. I should do a back-to-back comparison

@AntaresSQ01

Жыл бұрын

@@superduked33 I mean for spirited street riding with occasional track days it's hardly ever going to be a limitation but I don't want to go quite so stiff, for street I think a progressive spring to counteract the dive is the way to go. Will be looking forward to the back to back comparison.

@superduked33

Жыл бұрын

@@AntaresSQ01 You might be on to something there my friend. Could be a perfect solution. If it helps, remember that ratio is digressive by -8%. Hopefully you can use that to help choose the right % of progression to your new spring

@gabrielibarra5551

6 ай бұрын

​@AntaresSQ01 if you ever get this idea off the ground i would love to be the first to hear about it! Moving the upper mount forward seems like the perfect solution, a more cost effective way to increase rear ride height (if the mount can be slightly lower than stock, plus maybe a spacer on the swingarm side) than getting a ride height adjustable aftermarket shock PLUS getting 15/40 gears (which might not work for everyone) and 114 link chain to push the eccentric hub as far back and down as possible, as superduked mentioned in multiple videos. I would definetly buy this if it ever gets made

Great video! I recently took my 1st Gen to thunderhill and it ran like a champ. Exactly what you mentioned, it dominated in the braking and turn speeds. My only complaint is the brakes are not smooth on the initial bite maybe I have warped rotors? And the throttle profile is long!! I got wrist pains bending my wrist all the way down every exit. Any solutions for these?

@superduked33

8 ай бұрын

Yes to both. KTM sells shorter throw throttles. Rotors you can check with a dial indicator. Put your bike on a front stand, secure this base somehow, adjust the dial indicator so it's touching the rotor surface, and slowly spin the wheel. Here's a link to a cheap dial indicator kit: www.amazon.com/Indicator-Magnetic-Precision-Inspection-NAKAO/dp/B08L77HY82/ref=sr_1_1_sspa?crid=1IK6JZFW0XGSJ&keywords=mic+dial+gauge&qid=1698027140&sprefix=mic+dial+guage%2Caps%2C132&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

@DavidLee-kb3mi

8 ай бұрын

Thanks, I'll have the shorter throttle throws for next season. I'll probably take your advice with the sprockets too and the brake rotors.

Hi Eric, any issue with the chain scratching the frame by mounting the 15T pinion, as you explained in the 3gen video? Even if keeping the std 38T in the back, if you ever tried it? With this configuration 15:38, do you have enough adjustability with the rear axle eccentric. Thanks

@superduked33

Жыл бұрын

Rossano I have actually done a TON of testing sprocket combinations, measuring wheelbases, measuring ride heights - all in the last two weeks, and not just with one chain length but with three different chain lengths. Today I am actually filming a video specifically about this subject. One of the problems with our 1290 SDRs is the countershaft sprocket is actually located LOWER than the swingarm pivot. Most bikes, nearly all sportbikes in fact, the countershaft sprocket is higher. I have not measured whether the Gen3 is different than the Gen2 but it might be, because I never ran into a problem with the chain rubbing the swingarm with a 15 sprocket up front. But as you mention, I have run into this problem on the Gen3. But only when the eccentric/axle is rotated rearward and down (which is actually a better place to have your axle on an SDR in my opinion for several reasons). So in my opinion you would be better off using a different combination instead. Since your choice of 15/38 is a 2.56 ratio, but gives you a much shorter wheelbase unfortunately, you could use a 17/43 which is a 2.53 ratio (nearly identical) but with a 116 link chain which will give you 10mm longer wheelbase than stock. More swingarm angle, more load on the front, less trail for quicker steering and less squat on hard acceleration

@rossanodimonte2520

Жыл бұрын

Why do you say 15:38 is going to shorten the wheelbase compared to the oem 17:38? The pinion 15T has a smaller radius and the sprocket the same. Is it because the 15:38 solution needs to take away a chain link to fall within the eccentric adjustability?

@rossanodimonte2520

Жыл бұрын

A higher pinion location as well as a higher sprocket pull (sprocket radius) would increase the squat effect. Ideally the pinion should be located aligned with the pivot, there were attempts in the past on both motorcycles (Husqvarna i remember) and MTBs.(trek). But it is complicated and reduces other possibilities. As far as you have the pivot high enough to prevent squat, the lift of the pinion position is negligeable i guess but he solution more practical

@superduked33

Жыл бұрын

@@rossanodimonte2520 This makes for very fascinating (to me) conversation and debate. I say debate because the higher up you go on the intelligence chain, the more opinions vary as far as "insert your favorite name here - I call it chain pull". From what I end up with after years of debates and conflicting science fiction, yes, I agree with you, a higher chain drawing from a taller rear sprocket under hard acceleration does have an affect on squat. BUT.... and this is the debatable "but" that I have nearly lost friends over, the other more impactful contributor to "squat" or in the case of increasing swingarm angle, "anti-squat", is the angle of the swingarm itself. Swingarm angle of course being the position of the axle center related to the canter of the swingarm pivot. Basically put the lower the axle the more anti-squat, the higher the axle the less. And in the case of this conversation, anti-squat is not just the absence of squat, but the force that drives against squat. That actually lifts the rear of the bike as you accelerate. Obviously you already know all about this Rossano, so my answer here is more for anyone else who might be tagging along. As I have come to understand the differences between these two forces, one being chain pull, the other being swingarm angle and its resulting anti-squat which generates from the forward force being applied to the axle center which is now lower than the swingarm pivot.... the latter of the two squat vs anti-squat forces is increasingly greater the lower you place that axle. Which in turn can be a much stronger force, and have a greater impact on "squat" or in this case "anti-squat". Great conversation Rossano

@rossanodimonte2520

Жыл бұрын

It is exactly as you said, the chain pull (always) squats, the "traction" force acting toward the rear axle...squats or anti squats depending on the axle position with regard to the pivot. An engineer has to balance the two. And this is dynamic too. You may have a great swingarm angle, but a very weak spring (or excessive sag setting) in relation to the weight/grip/g-force with the result of putting again the axle in line or above the pivot at mid-turn maximum compression, when you pick up the throttle... There are many calculation softwares and phisical explanation in the web to make this topic "arguable"...

Are you measuring swingarm angle at ride height or fully extended?

@superduked33

Жыл бұрын

Always fully extended

@Lumpys_Garage

Жыл бұрын

Thank you

Did you go to a 190/60 tire to get the increased diameter?

@superduked33

8 ай бұрын

I ran the 200, same as I do on the Gen3. In fact my buddy still races my Gen2 and we swap tires often