KTM Forums banner
1 - 20 of 122 Posts

·
Registered
Joined
·
625 Posts
Discussion Starter · #1 ·
So I finally pulled the trigger sold my BMW K1300S HP. I loved the bike butt really missed the relaxed ergos of larger Adventure bikes. Dam bike had a taker on Cycle trader in 5 days. Any hoot I decided on a 1290 SA S. what a great machine common up on 300 miles. I love it. I have had a 1190 Adv R a 1290 SA T, and loved both of them. Any hoot what do I do with all my bikes. I make up a second set of wheels, Usually to make them better at their alter egos. For the 14’ 1190 Adv R I made up a 19” - 17” set for road use. For my 1290 SA S I used that second set to put knobies on for off road use.

In 2019 I got a 790 Adv R and had Warp9 racing make me a pair of Supermoto 17” wheels for it. This is my other bike that I keep at my vacation home at the beach. So if I want go to the Pine Barrens in Jersey I put on my 21 - 18’s with the stock Karoo’s and away I go. If I want to just be a street hooligan I put on the 17’s. BTW the 790 with the 17’s is the best handling street bike I have ever owned. Just wanted you to get an idea where my head is.
Anyway the 1290 SA S comes with a 19” - 17 setup. This is mainly aimed at having a bike that can do sport touring while still giving it decent capability do light off road fire trails etc. While the bike handles incredibly well mainly due to the suspension which is really sick. You do however still get the gyroscopic effect of the lager front wheel. So what if I made up a 17” front tire with a custom tone ring. This would make the bike even more street biased and the handling would be incredible. It would be a Super Duke GT with ergos that actually fit me as I am 6’-5” 255 lbs.

I started looking into this and see the new 790 Dukes have the same cast wheel pattern. I can get a black wheel set up with all the internals new for just less than $400. I already have a second set of rotors and the only other thing I will need is a custom 45 tooth front tone ring and a tire. So for roughly $600 I can swing the deal.

So do you guys think this is worth it or should I just leave well enough alone. I am a tinkerer. So it’s just like making a better mouse trap. Still $600 I could spend on other performance upgrades. Your thoughts


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
625 Posts
Discussion Starter · #2 ·
I am thinking before I dive in on the 17” Duke wheel I will simply put the current 17” front wheel from my 790 Adv R Supermoto setup. Just to see what the new wheel and geometry actually end up doing. If it is a success and make an appreciable difference then I will be in. I’ll let you know how it works out. It will screw up then MTC ABS so I will have to get a custom tone ring made.


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
625 Posts
Discussion Starter · #4 ·
No need for custom/specials, I normally keep these on the shelf 👍
Ian if I end up going this route I will let you know. So how much fo just the 45 too th front tone ring? Have a great day!
 

·
Registered
Joined
·
109 Posts
My personal opinion? The 1290 SAS is as close you can get to perfection and I wouldn't mess with it. If anything, my only complaint is the low-speed front wobble when full loaded (it's most noticeable with one hand on the bars). That's a geometry problem with raising the rear to compensate with the load. So I think putting a smaller wheel in front might amplify that issue. But that's just a guess. If you do end up doing the mod, please report your findings... I think considering putting tubeless spoke wheels is a good idea if you expect to do some light trails or fire roads. The cast wheels bend easily.

But if you are a tinkerer and absolutely need to tinker, again I would recommend doing the Rottweiler stage 4 airbox/PC5 mod with race exhaust. Instructions are clear and you can do it yourself if you're a B- / C+ mechanic and have the tools. And then, my friend, you will discover what that bike is really capable of.
 

·
Registered
Joined
·
24 Posts
Ian if I end up going this route I will let you know. So how much fo just the 45 too th front tone ring? Have a great day!
Grizz, I normally sell them as a pair for GBP £90 a set, but could split a set and supply one for £60. But you'd be far better having a pair, and correcting the speedo at the same time. Just give me a shout if and when 👍
 

·
Registered
Joined
·
625 Posts
Discussion Starter · #7 ·
Grizz, I normally sell them as a pair for GBP £90 a set, but could split a set and supply one for £60. But you'd be far better having a pair, and correcting the speedo at the same time. Just give me a shout if and when
Grizz, I normally sell them as a pair for GBP £90 a set, but could split a set and supply one for £60. But you'd be far better having a pair, and correcting the speedo at the same time. Just give me a shout if and when
IanC. Well I rode the 1290 SA S pretty aggressively this last mid week with a couple of buddies shredding the Blue Ridge Mountains. I loved the 1290 SA S but at moderate to high speeds I really missed having a 17” front wheel. So in a weak moment last night I ordered a 790 Duke front wheel. Imagine that. So I am in need of the 45 tooth front tone ring. I can use PayPal to order. Let me know how I can finalize ordering this. I have sent you a message reflecting the above. I would suspect several weeks to get the wheels. I will keep everyone posted on new front wheel geometry affects. I may pull the stock steering dampener and take out the 20 wt oil and put in some 65 wt oil to stiffen it up. We shall see.


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
24 Posts
So I am in need of the 45 tooth front tone ring.
I can supply you just the one 45 front ring if you like, but I'm sure you'd be better fitting a pair and fixing your speedo in the process. This will also cut your odo down and stop you having more services than you need. In about four years of sending out rings, I've not once done a single before!

You probably need 46R and 43F to do this. But, 17/17" on a 1#90 uniquely can work out borderline between two different sized rings, and I've supplied two different sets for this setup. So the foolproof way is to accurately measure both wheel circumferences. I dare say you know how to do this, but the best way is to make a mark on the tyre, put this at bottom-dead-centre, and make a mark on the floor. Push straight until the mark is in the exact same position (one full revolution), make another mark, and then carefully measure this distance in millimetres. Make sure your tyres are correctly inflated first.

Anyway, whichever you choose, the easiest way forward is if you can message me your email address please.
 

·
Registered
Joined
·
625 Posts
Discussion Starter · #9 ·
Ian

Here are the results from a spreadsheet I made to calculate the correct tone ring size based upon stock OEM setup. I was thinking it was a 45 tooth but as you can see it is a 44 tooth front end. This will keep passive pulse for the front tome ring to with -0.57% of stock a 45 tooth front give a +1.62%. This will result in a correct speedo reading and will the bikes ABS/MTC will not know the difference between the two set of tires. Which if it did would cause a general failure in the MTC/ ABS system. I used this to calculate the tone rings required for my 2019 Adventure R when I went to 17" Super moto set. The corrected ring sizes in this case were 41 front, 45 rear. The ABS/MTC on the 790 Adv R in Super moto set up functions flawlessly. My email is [email protected]
 

·
Registered
Joined
·
625 Posts
Discussion Starter · #10 ·
Ian

View attachment 99237 Here are the results from a spreadsheet I made to calculate the correct tone ring size based upon stock OEM setup. I was thinking it was a 45 tooth but as you can see it is a 44 tooth front end. This will keep passive pulse for the front tome ring to with -0.57% of stock a 45 tooth front give a +1.62%. This will result in a correct speedo reading and will the bikes ABS/MTC will not know the difference between the two set of tires. Which if it did would cause a general failure in the MTC/ ABS system. I used this to calculate the tone rings required for my 2019 Adventure R when I went to 17" Super moto set. The corrected ring sizes in this case were 41 front, 45 rear. The ABS/MTC on the 790 Adv R in Super moto set up functions flawlessly. My email is [email protected]
So going with a 44 tooth front tone ring.
 

·
Registered
Joined
·
625 Posts
Discussion Starter · #11 ·
My personal opinion? The 1290 SAS is as close you can get to perfection and I wouldn't mess with it. If anything, my only complaint is the low-speed front wobble when full loaded (it's most noticeable with one hand on the bars). That's a geometry problem with raising the rear to compensate with the load. So I think putting a smaller wheel in front might amplify that issue. But that's just a guess. If you do end up doing the mod, please report your findings... I think considering putting tubeless spoke wheels is a good idea if you expect to do some light trails or fire roads. The cast wheels bend easily.

But if you are a tinkerer and absolutely need to tinker, again I would recommend doing the Rottweiler stage 4 airbox/PC5 mod with race exhaust. Instructions are clear and you can do it yourself if you're a B- / C+ mechanic and have the tools. And then, my friend, you will discover what that bike is really capable of.
There is plenty of grunt in the 1290 SA S the way it is. More power just mean scarier quicker. The bike is as you say close to perfection. For me it just is feeling the bike and the 19" wheel does offer more centrifugal force which leads to pushing it into turns at higher speeds. Not that I am not use to it. The 17" front just reacts to thinking direction so just a better experience for street use. I'll keep the 19" for when I am thinking I'll be running some fire trails or gravel rods. I am going to go ahead with my 17" front wheel conversion. I will post results. If it is anything like my making a 17" supermoto set for my 790 Adv R, it is going to be epic.
 

·
Registered
Joined
·
24 Posts
OK I've input your measurements to my spreadsheet, and agree on 4-slot differential 👍 (three is usual for 17/17"). But to get everything correct based on your figures I'd do 42F and 46R.

BTW in my experience calculating tyre circumferences based on rim sizes and % profiles as I think you've done isn't accurate, real-world measurements are usually considerably different, e.g. for a 170/60 x 17" rear, measurements have ranged previously from 1930 to 1975mm, and yours is above this range.

Anyway, I'm emailing you now....
 

·
Registered
Joined
·
625 Posts
Discussion Starter · #13 ·
Let me measure the existing tires to confirm. an then I Will get back to you.
 
  • Like
Reactions: IanC

·
Registered
Joined
·
625 Posts
Discussion Starter · #14 ·
So I measured the front tire measures 79” in circumference which is 2.4% less than the calculated circumference of 80.469. So the real question is how much error is allowed before the system creates error messages. So if you assume the new 120/70 17 is as I calculated a 45 tooth front tone ring will correct to within .12 %. If we assume assume a high side do 23.93 diameter then yup only need a 46 tooth front tone ring to connect. So I can see that tires vary by 2.5% or more which means that you could be off by 2% plus in pulse rate. Of course there has to be variance in the MTU’s to deal with this variance between tire sizes. So what do you have for readings on Pirelli Angel ST’s or Scorpion trail 2 120/70 17R tires. Because to be exact as you can see equalization can be achieves with either, 44 , 45 or 46 tooth tone rings depending on variables. I would guess though that 45 in the middle is a good guess because it is in the middle of variability. I would guess the internal mtu’s must compensate for these variables. If you leave the stock tone ring though the variable 8% to 10% which the systems can not handle. So to be exact we would need to wait and measure the inflated tire on the rim.


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
24 Posts
Yes, I've been through all this some years ago! :D Actually there's considerable tolerance between both ends before problems occur, though I couldn't tell you what it is.

The only reliable way is to measure the circumference accurately, as there's a discrepancy between theory and reality. I suggest the method I described (both wheels), and would also suggest correcting the speedo. I do at times send out ring sets just for this purpose, so you'd be killing two birds with one stone.
 

·
Registered
Joined
·
625 Posts
Discussion Starter · #16 ·
I measured both tires last night so I will measure the 17" Front when it gets here. Also fyi the 790 Duke front wheel assembly will not work the Rotor and is based upon attachment points which are dissimilar to the 1290 SA S. I have looked at the 1290 Super Duke Rotors and attachment point as well as tone ring configuration and again they are dissimilar. Without doing a lot of custom parts it seems the only setup that will work is the Supermoto wheel set up I used on the 790 Adv R. So the question is do I want to do a another Supermoto front or I can just rotate that wheel between bikes and only change the tone ring between setups. Got to think about that one.
 
  • Like
Reactions: IanC

·
Registered
Joined
·
89 Posts
Since I had to buy SD roto
rs anyway, I got these racetech rotors from rottweiller. And superduke monoblock calipers.
 
  • Like
Reactions: Grizz

·
Registered
Joined
·
625 Posts
Discussion Starter · #19 ·
So it appears you had to get. SD wheel with SD rotors, did you have to do the caliper blocks or was that your choice. Also is that an SD fender? What did you do for a tone ring? I have calculated that you need a 45 tooth sensor to account for the higher rpm of the 17” vs the 19” front wheel. This would correct speedo and balance the ABS/MTC systems. But you would need a modified SD sensor ring to 45 tooth. I am thinking that in order to keep rotors and associated calipers etc., of going with a super moto 17” spoked wheel. That way I get a custom tone ring, which Warp9 racing is building me and I should be good. I had them build a set for 17” super Moto wheels my 790 Adv R . It is an ridiculous canyon carver with them. I wanted to go with either Super Duke 1290 or 790 wheels but a lot of things like rotors and calipers alignment just don’t add up. I can get a complete tuneless 17” front spoked tuneless wheel with rotors for around $700 so $150 fro the front tire and we are done. How much did the sad fender run you? In the end do you think is worth the $850 investment for me? How much was you total investment going your route? Looks awesome dude. I am sure it’s handling is just at another level. Like driving an SD with comfy ergos. Which for me is the deal. At 6’-5” 260 lbs.


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
625 Posts
Discussion Starter · #20 ·
I love the pipes how did you paint or coat them.


Sent from my iPad using Tapatalk
 
1 - 20 of 122 Posts
Top