The Supermoto KTM should have built

[jumph4x]

Conan, were you riding with Dennis on his SMT? When we blew past you guys on Navarro Ridge he looked like he was really struggling. I felt kind of bad for him.

Who is Dennis? I didn't see any SMTs at the event...

 

[cencalballer]

I think this one will probably get viking funeraled. But if it does get sold, it'd probably show up on BARF for sale, much like the owner's previous bikes.

I could also be convinced to build another, for a price.

So Jump4hx or whatever his name is did the conversion.

 

[Lunch Box]

Riding with Denis on this bike? Yeah, I was on the white 690 SMC. If you felt bad at that point, wait till you hear the rest of the story.

I'm listening...

We certainly had our little slippy-slidy mishaps here and there. Good times. arty

Who is Dennis? I didn't see any SMTs at the event...

Wasn't that an SMT you were on? Looked big and tough to handle.

 

[RightCoastBias]

I would have assumed Jump would be on the 1290.

 

[Lunch Box]

I would have assumed Jump would be on the 1290.

You are likely correct. I didn't see it for very long. It was a large KTM. That's as much as I got.

 

[Blankpage]

Does that project bike handle well at speed? Geometry looks a little wonky

 

[Lunch Box]

I was thinking that it should be pretty stable, given the rake and trail. Should be semi decent on rough roads, too. I would love to swing a leg over that beast one of these days. I applaud the creativity, and the willingness to mess with a pricey toy. Cool stuff.

 

[Hooli]

 

[UDRider]

Nice bike.

 

[Z3n]

So Jump4hx or whatever his name is did the conversion.

I built the bike to meet the desires and requirements of jumph4x, but it's his bike.

Does that project bike handle well at speed? Geometry looks a little wonky

I've only had it to 110 or so, but it was rock solid at up to that speed. We'll see what it looks like at proper speed when it goes to the track on June 11th.

I was thinking that it should be pretty stable, given the rake and trail. Should be semi decent on rough roads, too. I would love to swing a leg over that beast one of these days. I applaud the creativity, and the willingness to mess with a pricey toy. Cool stuff.

I was a little concerned about how it would handle offroad, with the TKC80s, and the amount of power it has, and the immediate way I would describe it is confidence inspiring. Confidence inspiring to the point that it took me about 500 feet before I was sliding the rear tire on the throttle, jumping it off crests, and laughing out loud in my helmet. I did all of the math rather carefully to make sure that the length of the fork extensions, the changes to rear ride height, and everything else stayed in balance. Regardless, though, when all components are done (i'd like to add a little more rear suspension travel and get it matched to 200mm Front/210mm Rear or so) it will get the proper measurements from GP Frame and Wheel when we have the time to get it out there, and we will use his feedback to establish the range of good geometry and ride height available.

Nice bike.

Thanks guys

 

[ctrvl]

Thou art a sorceror, and thine magicks shame the gods.

 

[sjuels]

This is the bike I want!
It is gorgeous !!

I have been thinking about this for a while; my idea was to start with the super adventure and then rip shit off it and slim it down, but now I see the error in my ways

This would be the absolute perfect bike for me; I make most bikes look like clown bikes, and geometry looks perfect for the size engine etc.

Maybe Austria does not have a Happy Hooligan culture (yet)?

/Soren

 

[corndog67]

Well Daddy'O, that is damned cool.













What is the story with that set of CBX carbs on the shelf?

 

[Chill]

I think this one will probably get viking funeraled. But if it does get sold, it'd probably show up on BARF for sale, much like the owner's previous bikes.

I could also be convinced to build another, for a price.

Yes please.

 

[anytwowilldo]

The 1290 SuperDuke was the first new motorcycle I ever bought. You can read about the my 1290 ownership experience in my previous threads, but if I'm being completely honest, the 1290 SuperDuke isn't actually the bike I wanted from KTM. What I really wanted was a 1290 SM-T. While the KTM excels at what it is laid out to do, the most compelling bikes KTM has made have always been the supermotos - in particular, the 990 SM-T. There's something about massive suspension travel paired with big power that makes for an awesome urban warfare vehicle. It's the bike that has your back no matter what you're throwing at it, with a large, upright, commanding riding position, high spec brakes, high spec suspension, and ideally a full electronics package.

A year after I got my KTM, the itch really started to get to me. So I did the preliminary research and looked for the possibilities, and it looked...possible. But at the time, it didn't make sense to turn the KTM into something different, as I was commuting on it every day, and I didn't really want to pull my street bike off the road for the build, and the concept stayed nascent.

Until, of course, I ended up converting a buddy's 1290 racebike back to a streetbike, and I casually dropped a line listing it for sale among friends, and sure enough, someone came out of the woodwork to buy it...and also ask if I'd be willing to do the supermoto build.

And so it began.

First acquisition was a lucky snipe of an Adventure R shock off of eBay, and discovery that the OEM exhaust on the 1290 offers millimeters of clearance between swingarm and exhaust. But an 1190 or 1290 Adventure header would bolt on directly and return ground clearance, and also fix the issues with the swingarm fouling on the OEM 1290 SuperDuke catalytic converter box.

Ready for shock install:

Because the header is shared between the 1290 and 1190, the design can be expected to be reasonable for the 1290 SuperDuke, despite slightly different tuning. With that, we hit the super exaggerated phase for the bike:

This brings total ride height in the rear up roughly 70mm, increasing rear travel to ~190mm, and increasing bottomed ride height by ~30mm.

And the side by side of the bike next to my stock ride height 1290:

And, of course, no prototype KTM would be complete without two tone wheels, so those went off to the powdercoater for the orange and white treatment.

Next up was forks. Research of variations between the WP fork designs, part number cross referencing, etc, eventually lead me to discover that any of the 48mm WP forks would bolt on and be compatible. I could explore swapping the fork bottoms as well, but axle sizes have been the same between KTMs for years while cartridge designs have changed, so some more exploring lead me to discovering 950 SM forks would offer 200mm of travel, with roughly +15mm of ride height at full bottom, while maintaining the same upper fork length. They also had dual front rotors, that would be a straight bolt on for the M50 SuperDuke calipers. A set of forks was found on ebay, and bolted on:

The rest of the front end was sorted out by brake spacers spun out by the ever helpful WW Resto, Venhill custom lines in orange, and a 950 lower beak. I also found that the lower front fender mount would fit the front wheel sensor, so that was a pleasant bonus.

At this point, I zip tied on the front beak and fit everything to see how it would line up, and it seemed to be coming together ok:

Despite the street cred of running your supermoto without a kickstand, it was decided to be slightly more sociable and replace the speed block for the kickstand with an 1190 Adventure kickstand, giving it some independence from the usual supermoto style of leaning the bike against anything that would hold it up at a stop:

Next up was getting the seating position right - that meant replicating the 1190 Adventure design, which has the footpeg mounts going straight into the frame. Obviously that wouldn't work for this build, but I quickly machined up a prototype rearset that adapted the normal rearset mount to something that would accept ADV-R foot pegs, and some ebaying found me a 640 Adventure rear brake lever that would work for the use case. The prototype parts are...industrial, to say the least, but will be replaced by a more aesthetically pleasing set now that the design has been proven out. On the shifter side, an Adventure R shifter bolts right on and clears everything.

Handlebar height and sweep was fixed by a 690 Duke bar, which is absurdly tall for a Duke 690, but just perfect for a 1290 SM-R. The Venhill lines made this side of the swap very easy.

At this point the bike was actually rideable, although with some caveats, the exhaust mount was ~90mm behind the OEM mounting point, and the exhaust was somewhat spaced out from where it should be. And so I rode it to work for the first time, after dropping the forks a few MM in the triples to try and get the handling just right - and as it all turns out, I managed to nail the geometry in the bounds of normal straight out of the gate - it handled beautifully, although the rear was quite oversprung at this point, with the 1190 having a much longer swingarm and running a higher spring rate as a result.

And with that, it was time to fit the front fender - as it turns out, 60mm fork mounts aren't exactly in common supply, but a 61mm Harley Davidson fork brace can be machined down, tapped a bit, and pressed into service as a fork mount for the upper fender. It's rather appropriate, I guess. With the handguards installed, now the bike looked like this:

And with that, the bike was turned over to the owner for some final items, like getting 90mm chopped out of the exhaust (thanks to Dennis at Norman Racing in Berkeley for super quick turnaround on that!). And of course, because the natural thing to do with a SuperMoto is to send it awkward places, it was time to throw TKC 80s, an 1190 Adventure skidplate, a guard to protect the R/R, and some mirrors on it and send it to the SheetIron 300.

And yes, it's a completely inappropriate bike for that, and we learned some lessons about that. But you don't stress test a bike to discover how little it can do, you stress test a bike to discover how far it can go. And we learned that, although ironically the head splits weren't the problem...but that's a story for a little later:

As I passed three of you guys riding in a row on Low Gap road, I though I was in a Mad Max movie for a moment. That bike looks totally cool and it was rolling pretty fast. Another take on the dual sport theme. I like it!

 

[Hooli]

Needs a louder pipe.

 

[horsepower]

Holy awesome, batman!

 

[Kestrel]

Curb weight?

 

[Z3n]

Yes please.

Thou art a sorceror, and thine magicks shame the gods.

Holy awesome, batman!

D'aww, thanks guys!

Curb weight?

Assume roughly the same as OEM. The 1190 header is much lighter than the OEM header, but the forks, crash cage, etc, probably wrestle that back. 450 pounds, give or take 10?

Needs a louder pipe.

Loud pipes are for gixxer owners.

As I passed three of you guys riding in a row on Low Gap road, I though I was in a Mad Max movie for a moment. That bike looks totally cool and it was rolling pretty fast. Another take on the dual sport theme. I like it!

Glad you got a kick out of it! It was a good time!

Well Daddy'O, that is damned cool.

What is the story with that set of CBX carbs on the shelf?

You think I only build bikes with electronics?

Well, you'd be right. CBX getting updated to modern spec - 17s, cartridge forks, modern suspension/swingarm, ABS.

This is the bike I want!
It is gorgeous !!

I have been thinking about this for a while; my idea was to start with the super adventure and then rip shit off it and slim it down, but now I see the error in my ways

This would be the absolute perfect bike for me; I make most bikes look like clown bikes, and geometry looks perfect for the size engine etc.

Maybe Austria does not have a Happy Hooligan culture (yet)?

/Soren

jumph4x is pretty tall, and this fits him well. Seat height is not for the faint of heart, though - I'd estimate with the high seat I prefer, it's ~38 inches with supermoto sag, not dirtbike sag (assume ~1 inch). Normal seat, around 36-37 inches. I can ride it with a 30 inch inseam, but it's very tall.

 

[ohio]

RAD.

Where/when are you posting the rest of the sheetiron story?