Steering damper kit - Am I missing finding one? Who's interested?

[Formula390]

I had searched around online, and didn't see anything but maybe I missed finding one. I'm kinda shocked the bike didn't come with one out of the box, but whatever...

Anybody interested in a steering damper kit for the front end of your 390? I dunno about y'all but I'm finding the bike a tad bit "twitchy" when I'm REALLY throwing it around on the back roads here in Central Texas. I managed to get a pretty good front end tank slapper when I hit a patch of sand on the side of the road slicing through a tight right hand corner... stayed on the gas and it settled out, but that's it. Time to put something together... but, I figured I'd check and see if anyone else is interested too. I'll probably fabricate the brackets on my desktop CNC out of aluminum, but if there is enough interest then I might make a mold and cast a bunch with a higher strength zink alloy like ZA-12 instead.

Not sure on what the price would be if I made a kit. Probably in the $100 realms tho, +- $20... this is a total SWAG, but I think it should be possible to put a quality kit together in that price range... but don't hold me to it until I get an idea of how many are interested and start modeling the bracket.

 

[gbabyracing]

I need one now. I don't think you can do it for that price. Not one that works anyway.

 

[gbabyracing]

Or are you talking only about a mounting system?

 

[Formula390]

It would be the mount system. Yeah, obviously a quality damper is going to cost about that much as well... unless one were to find a decent used one, but you've still got the mount problem then.

Once there is a mount location/bracket, then you could select and use said mount to attach a generic off the shelf damper from the forks/triple to the frame. Most seem to use 8mm bolts, tho I could always make the bolt location larger and a bushing could be used... or if necessary one could drill out a 8mm bolt location to accept a larger bolt if their damper required it. Providing extra material around that location to allow for that wouldn't be a big deal... I wouldn't want to select the damper for everyone to be required to use, tho I could certainly provide that as an option if one wasn't looking to source one themselves as well. The chief problem is mounting locations... I've looked all over the frame, and near as I can tell... there just isn't one!

One can readily find a generic off the shelf damper cylinder, so I wouldn't have to manufacture those, nor honestly would I want to... but none of the generic dampers have any means of easily bolting it all onto the bike without having to fabricate at least one bracket to the frame, from the looks of it. There's the two available bolt locations on the lower triple, or a generic fork tube mount... but there doesn't appear to be any (at least stock) corresponding frame mounting location (at least that I can find) to attach the other end of a damper to... so some sort of bracket would have to be fabricated to link the forks / lower triple to the frame. That's what I'm going to have to fabricate... at the very least for myself. I figure, others certainly have to be experiencing the total lack of a damper as well tho. That tank slapper was NOT fun tho. I have zero desire to experience THAT little bit of drama ever again on the 390. I've got zero desire to build a piece of motorcycle jewelry to pose with... my aim to to fabricate a quality kit that one could then use whichever damper they wanted. Getting it to fit and clear the forks and bodywork will be the tricky part from the looks of it tho... there's not a lot of extra space in there!

 

[gbabyracing]

I'm in! You get more interest from racers required to add one. CMRA for example requires it. Linear and progressive units a very available.

 

[micahpearlman]

I'm in! You get more interest from racers required to add one. CMRA for example requires it. Linear and progressive units a very available.

I was getting a minor, but unsettling, head shake when turning in to certain fast corners (no brakes just off throttle). I was putting that to stock suspension which was causing the geometry to be a bit choppered out. I have updated the suspension and go into my next race this weekend. If I am still getting the head shake I'm in.

 

[Formula390]

I'm certainly in the Big Boy club at 210#... So I'm interested in how your suspension update helps too. I've got my rear at max, but no adjustments on the front (noon cup bike) means I'm going to have to at LEAST put springs on it...

 

[micahpearlman]

I'm certainly in the Big Boy club at 210#... So I'm interested in how your suspension update helps too. I've got my rear at max, but no adjustments on the front (noon cup bike) means I'm going to have to at LEAST put springs on it...

My guess is that your tank slapper is the same issue I had (not exactly a full slapper but not pleasant). The rear shock is just too short to begin with and sagged out for us bigger guys turns it into a chopper. I'm assuming you are street riding so in that case, where ground clearance isn't a major issue, I would consider dropping the front end to see if that helps. If that does help, ideally what you want is a longer rear shock. I'll keep this thread posted on if the new suspension cured my issue.

 

[Formula390]

My guess is that your tank slapper is the same issue I had (not exactly a full slapper but not pleasant). The rear shock is just too short to begin with and sagged out for us bigger guys turns it into a chopper. I'm assuming you are street riding so in that case, where ground clearance isn't a major issue, I would consider dropping the front end to see if that helps. If that does help, ideally what you want is a longer rear shock. I'll keep this thread posted on if the new suspension cured my issue.

Oh, mine was a full fledged lock to lock to lock slapper until traction was full regained. I managed to keep my hands on the bars, but I certainly was in no way shape or form in control for that split second which always feels like an eternity. LOL

As for how your suspension modifications pan out this weekend, yes please do let us know how it works out.

As for my initial ideas after poking around on the frame a little more, the only spot I can see that looks like it would READILY accept a bracket is the horn mount. It LOOKS like it would likely be sturdy enough to accept a damper bracket to then attach either to the forks or to a second bracket which would attach to the triple lower utilizing that bolt hole there on the front left side... Racers would likely just pitch the horn, so no problem there... for street riders, relocation of the horn (likely just moving it an inch or three) onto another point on this same new bracket would likely be the solution for that. {shrug}

I'll have the bike stripped down this weekend to do the initial servicing, so I'll be able to poke and measure and see about prototyping a mount (probably on the 3D printer just for basic design and fit) but the only other obvious attachment point looks like it would require some sort of clamp for the frame if one didn't want to weld an attachment point onto the frame which I strongly suspect most would be quite adverse to doing.

I'm also certainly open to feedback for an alternative attachment point and/or other ideas.

 

[SPG]

I was thinking of making a milled aluminum bracket that spans the frame just behind the steering head bearings and in front of the battery box. It would then form the anchor point for a Scotts or GPR style damper which would fit on the triple clamp. Only downside is not nearly as cheap for the damper.
-Sean

 

[Formula390]

I was thinking of making a milled aluminum bracket that spans the frame just behind the steering head bearings and in front of the battery box. It would then form the anchor point for a Scotts or GPR style damper which would fit on the triple clamp. Only downside is not nearly as cheap for the damper.
-Sean

Yeah... That might very well work... I'll likely never know however. Now... If you could tolerate a Scott's style damper. I rode a TL with one on it. While it was a VAST improvement over NOT having any damper at all, it still seemed lacking. I don't know if that was attributable to the frame, the suspension, the fact that ALL TLs just deep down at their beady eyed little souls (and I'm an admitted dyed in blue Suzuki/Gixxer fanboy!) want to do nothing other that wheelie or murder their rider, or the damper wasn't setup right... But I HATED that thing. So much so that I never reconsidered using a Scott's style ever again. Could be that my experience there has since irrevocably prejudiced me against that style... but I've not considered using one on the 390. I'd sooner (gladly) tank slap my way into a ditch than use (or pay for) one ever again...

 

[SPG]

I am a fan of as little damping as possible on the steering to let the bike balance it's own needs. However, my suspension guy described steering dampers as like earplugs; they just quiet things down enough to take the edge off and allow you to concentrate on more important things. To that end, I have found the Scott's and GPR to be perfectly functional and tunable, but certainly not a cheap addition.

In general I rather set the bike up so that they are not needed. If by bike is generating tank slappers, I have more important things to fix and relying on a damper to mask the problem actually reduces overall stability by not allowing the bike to self correct.

-Sean

 

[Formula390]

I am a fan of as little damping as possible on the steering to let the bike balance it's own needs. However, my suspension guy described steering dampers as like earplugs; they just quiet things down enough to take the edge off and allow you to concentrate on more important things

I'm pretty much in complete agreement there. I still think the RC390 will require a damper for bigger guys pushing the bike really hard, regardless of how well the rest of the bikes suspension is setup. I ended up having to fit a damper onto my MC18 NSR 250 when I raced it, and the suspension on that bike was spectacular. I think it comes down to a rider mass to bike mass ratio. I can ride JUST as hard on my CBR 1100XX Blackbird through the same corners with completely stock suspension and not have a hint of headshake. Do it on my Gixxer 1000 and I'm sure if I didn't have the damper on there, I'd get a bit of twitchyness. Attempting same on the KTM, and the bike might reproduce the headshake I ran into the other day. Now I also admit that the headshake was initiated by the loss of traction in the sand, and the bike DID quickly recover and settle out on it's own, but only because I stayed on the gas and let the bike dance around under me until it did sort itself out. If I'd fought it, or chopped the throttle, things certainly would have gotten much worse, much faster. If I'd have had a damper on the bike when the whole thing happened I'm also sure that there wouldn't have been any drama at all other than the front end would have stepped out a bit, regained traction, and I'd have kept moving on along without a second thought. {shrug} So, it could be that guys who have their suspension dialed it really well, and are far smaller mass wise, might not ever require a damper. Those of us in the Big Boy club tho... yeah... we're all probably going to require them. LOL

 

[Formula390]

OK Y'all... not sure who might have read the post over on my post over on my vendors section, but this is getting REALLY close to going in production. I've got all the parts prototyped in plastic, just for fitment and tests. The final pieces would be aluminum. There are two bracket assemblies. The first one clamps to the frame via two pieces with M8 bolts:

These pieces follow the contour and shape of the frame... and let me tell you have much fun THAT was to model in CAD accurately!!! Gah!!!! Anyway, the pin will bolt to the top piece of the frame clamp, which will be 1/2 round aluminum bar. This will be threaded to accept a M8 bolt. In this next photo I have a center punch in the hole for that bolt, but obviously the OD of the pin would be 1/2" not 8mm... but this photo will also show it's orientation and relation to the frame and show where/how it would attach:

The bolts for the frame clamp to lock those two pieces together and in place would be attached from the top down into the bottom frame mount piece, also via M8 bolts. I would be using cap screws, which would have the head of the bolts recess into the brackets. The frame clamp bracket assembly clears the battery box, tho that weird piece that bolts onto the front of it would have to be removed. It's just there to shield the wiring and this new bracket assembly would do the same job, so I don't think it would be an issue unless someone can come up with a compelling reason why that plastic piece needs to stay, I'm not going to worry about it. Here you can see the clearance between the battery box, and where the pin would then come in with relation to the triple tree bracket:

The upper bracket is comprised of three pieces. These are two "plugs" which come in from the bottom of the triple tree, and the large central piece which spans them and positions the damper directly over the steering stem. I may yet change the designs looks of the upper bracket to make it a little less "boxy", but the basic function and attachment would remain the same. Basically the two small plug pieces which fit in below the triple tree where those holes/ports are are placed in those cutouts on the upper triple tree, and the top bracket then sits on the top of the triple tree. These two plug pieces are how I'm getting around the other variants designs which then also require drilling and tapping the upper triple tree to attach the damper itself to, once again, using M8 bolts.

Oh yeah, and it all clears the stock battery box lid without a need to trim it either:

 

[nino209]

I had searched around online, and didn't see anything but maybe I missed finding one. I'm kinda shocked the bike didn't come with one out of the box, but whatever...

Anybody interested in a steering damper kit for the front end of your 390? I dunno about y'all but I'm finding the bike a tad bit "twitchy" when I'm REALLY throwing it around on the back roads here in Central Texas. I managed to get a pretty good front end tank slapper when I hit a patch of sand on the side of the road slicing through a tight right hand corner... stayed on the gas and it settled out, but that's it. Time to put something together... but, I figured I'd check and see if anyone else is interested too. I'll probably fabricate the brackets on my desktop CNC out of aluminum, but if there is enough interest then I might make a mold and cast a bunch with a higher strength zink alloy like ZA-12 instead.

Not sure on what the price would be if I made a kit. Probably in the $100 realms tho, +- $20... this is a total SWAG, but I think it should be possible to put a quality kit together in that price range... but don't hold me to it until I get an idea of how many are interested and start modeling the bracket.

GPR has one they used my cup bike to make it, i dig it here is a picture.
the mount kind of sandwiches the frame and then the tower bolts to that bracket, and they have a bracket for top clamp, no modifications to the bike.

 

[Muckabucka]

why not just fabricate a bracket that bolts to the front of the frame, and also a clamp for the fork tube. Of course that really would only work if you ditch the front fairing stay, but it would work. a la GSXR type dampner... That's what I plan on doing.

 

[Formula390]

GPR has one they used my cup bike to make it, i dig it here is a picture.
the mount kind of sandwiches the frame and then the tower bolts to that bracket, and they have a bracket for top clamp, no modifications to the bike.
View attachment 1402View attachment 1403

Interesting... have they just not going into production with it yet? They don't have it listed on their website as an available product. The only KTMs they list are the SuperDuke and RC8's. I had considered the frame clamp idea similar to what CJWell did with his kit, but I was worried about someone potentially screwing up and over tightening (possibly bending the frame) and that the contact area using that style of attachment is very small which could also result in frame damage. Maybe I'm being overly cautious, but that method of attachment just did not appeal to me At ALL! {shrug}

 

[Formula390]

why not just fabricate a bracket that bolts to the front of the frame, and also a clamp for the fork tube. Of course that really would only work if you ditch the front fairing stay, but it would work. a la GSXR type dampner... That's what I plan on doing.

I tried. Believe me! I spent almost 2 weeks trying to find a way to get it to fit that wouldn't require any modifications to the bike. Requiring the ditching of the front fairing stay wasn't a viable solution in my book as many riders wouldn't have liked that idea either. I had to design something that ANYBODY could do, with bolting onto the bike regardless of mechanical ability and requiring a minimum amount of tools. Something somebody who lives in an apartment with no garage and just the "101 pieces" tool set they have that their parents bought them when they moved out sorta thing. LOL Anyway, every method I tried that used the tubular style of damper (ala Gixxer) just could not fit without modifications to the bike or place components in an area that concerned me about potential damage to the frame in a crash... so, this is the solution I came up with.

 

[nino209]

Interesting... have they just not going into production with it yet? They don't have it listed on their website as an available product. The only KTMs they list are the SuperDuke and RC8's. I had considered the frame clamp idea similar to what CJWell did with his kit, but I was worried about someone potentially screwing up and over tightening (possibly bending the frame) and that the contact area using that style of attachment is very small which could also result in frame damage. Maybe I'm being overly cautious, but that method of attachment just did not appeal to me At ALL! {shrug}

i think they just haven't updated the website, but they are selling them now

 

[Formula390]

Mental note: Just because one is wearing Firemans Bunker Gear, does NOT mean one is COMPLETELY protected from molten metal. Had a small oppsie when one of the pieces of aluminum being fed into the foundry... apparently had a little moisture on it, or something. Pushed it down into the molten aluminum and VOOOSH up came a geyser of hot sticky molten metal! First time I'd ever had that occur. Anyway, that's what all the safety gear is for.

The vast bulk of the molten metal just splashed against me... but for one big puddle that must have run down my arm and collected in my right elbow. My helper RJ was a bit in shock and yelling "Oh My God!" again, and again, and again. I was doing a POST (power on self test) when I felt the HOT in my elbow right when RJ finally got out "Shit, your elbow!" as he'd seen the molten metal boiling on the gear... It had finally managed to burn through the outer layers of the bunker gear and was busily burning through the Kevlar and asbestos inner layers. I thrust my arm straight out, rotated sideways, and watched the aluminum pour out. A pretty surreal experience to say the least! The bits that had solidified and remained were still pretty hot! Slapping at it... my first reaction when "I'm on fire"... didn't help. I pulled the gear away from my skin, as best I could with the thick gloves on, and that helped. I got the jacket off, and it wasn't too bad. I'll have a few lines of a blister. About 1/8" wide and a few inches long. Heck, I doubt it'll even scar!

We melted down two more full charges of ingots, and then shook out the flasks to see how the pour went. Six good castings! Overall, another successful day in the shop.

Production continues. Monday I'll be casting some frame clamps and plugs for the triple mount. Tuesday machine these initial production run parts, and deliver everything to powder coating for testing the powder coating color options. Looking at the first run in both flat black and KTM orange for the initial five (or six, depending on if I scrap any parts while machining the castings LOL) production kits.