Tire Hugger idea


JSP

Super Moderator
Here's another set of questions: How long does this thing have to be? And, taking into consideration that I personally want it to be as small as possible, where should it be positioned? That is, over which part of the tire's arc should it be placed? Look at the gizmos on these two BMWs. Looking at them, I'm not even sure why these bikes have them, as both bikes already have full-coverage rear fenders that should be doing the trick. Is this added coverage for rocks maybe?

I suppose I can figure out the positioning by setting my SV on a rear-stand, then running the bike with the rear tire sitting in an elevated pan of water. I guess that will show me where exactly the water leaves the tire.

Any of you know your geometry and/or hydrodynamics and can just figure out what part of the rear tire needs to be shielded? I wonder if there is a YouTube video out there -- not sure why there would be, but I'll look...
It seems these huggers are more for stopping rocks from being kicked up and smackin the people behind you.
 
Y

yellowfz

The fender would need to be where the tire starts to arc back from vertical, pretty much exactly like those examples show. Below that line would shoot water and mud behind you. I'm just interested in keeping the water and mud off my back. Besides the water jet behind you keeps people off your rear when it's wet.
Yep , nicely stated .
It would keep the mud/water from slinging on to the taillight and riders back , whole purpose I had in mind was just that , with a FE the tire on our bikes can do just that .
Straight out from the axle and probably 15* off axis maybe 20* ? I would say like OCC does , use a chain thickness for spacing between hugger and tire , 3/4" or so , don't think our tires would pick up anything bigger than that .
Weather here is terrible so will slow me down a little getting parts together .
 
Last edited by a moderator:

Marthy

World Most Bad A$$ 6R
Elite Member
Cardboard and Clay Armature

After a misstep trying to mock-up something in paper mache´, I've built a base armature out of cardboard and clay (obviously nothing finished). That blue Sharpie line is approximately where I think the support piece from the chain guard to the fender will be. To give me clearance, I built up the tire tread with two layers of cardboard, chicken wire, and clay, though after hearing about tire carcass expansion at speed, I really have no idea what adequate clearance should be. One of you guys suggested making it the width of a drivetrain chain times two, so that's what I've got about.

Next, I'll smooth out and sculpt the rear fender and any details (where support joins fender and guard), then cast in Dental Stone reenforced molding plaster to make my mold. An engineering-student friend of mine (who drew the hydrodynamic sketch below) suggested making everything too big, so that I could simply cut the fiberglass piece down to size once it came out of the mold. The trick is to try and figure out beforehand what the smallest thing I can make now that does the job, yet something that doesn't end up being too flimsy and maintains rigidity at speed. We were also talking about the effects of the wind and even the rotation of the tire at speed.

On to that Too Much Fender size dilemma: what's the smallest amount of fender we can get away with and still keep our backs dry? We were using the hands of a clock to describe possible sizes and placement of the fender. Right now, my clay armature has a whopping 12 o'clock to 3 o'clock thing on there. But what about a 1 pm to 2 pm arc? Too small? 12:30 - 2:30? Frustrating because water pinwheels and in all sorts of crazy directions, not just in the obvious perpendicular line from the axle-to-tread. There's the nature of water, the shape of the tire, the tread pattern, and God knows what else.

Finally, a few of pics of my solo-seat polyurethane sculpture mess using the OEM tail plastic (red) as an armature. Unfortunately, just as I do when I cut my own hair in the mirror using electric shearers late at night, I cut too much away. So, it's back to the plastics store on Monday to get more stuff to build back up the tail and start sculpting anew. The problem is that the seat is so wide, yet the tail lights are so narrow. Even though I'm going for a "bobbed" look, I need more distance between the back of the seat and the lights, so that the taper down isn't so abrupt --- an ugly. Confusing? I'll post another pic when I've got what I think I need.





 

BrueThru

Sentient Being
Elite Member
Y

yellowfz

Okay , here is a mock-up of what I am after , quite different than SinSL's idea .
If I knew how to do fiberglass I would sculpt something a little lighter .
But you see what I am getting at , the part replaces the shim on the axle bolt and when you move the wheel for chain adjustment it moves with it maintaining the same distance at all times , part is not to heavy and will road test in a few days , just showing proof of concept .
 

Attachments

Last edited by a moderator:
Machine Shop Envy

Looks great! And you know as soon as that thing is done and mounted, every motorcycle enthusiast and his/her mother is going to stop and ask you all about it. It's probably that way with movie stars here in LA; at first they probably think it's cool that people stop them in the streets and ask for autographs, but after the first hundred or so, it probably gets really tiresome. You'll probably be talking to strangers about that fender until you sell the bike or die. The one downside to having anything virtually unique.

If I knew how to do fiberglass I would sculpt something a little lighter.
And if I had any access to metal fabrication equipment, facilities, and any talent in it, I'd be doing it your way.

As for mine, I'm just about done masking off the fender mock-up on the bike, so will probably cast the mold tomorrow sometime. With fiberglass, so much is in the prep -- screw that up and it makes everything that follows more difficult.
 

BrueThru

Sentient Being
Elite Member

CrazyCawi

New Member
I think you guys are really onto something!
 
Just an Hour a Day Hobby

You two seem to have alot of time on your hands. Both of you must be married. The married friends I have spend alot of time in the garage. :D
Not married, but pretty sure if I was, she wouldn't be letting me spend my insomniac hours knee-deep in fiberglass resin. Having said that, all of my girlfriends over the years have been into motorcycles. They sort of have to be if they want to hang with me.

As far as all that time I have on my hands; I can only spend about an hour a day on these projects, usually very late at night because we're not supposed to work on our vehicles in the underground parking structure here. Anyway, messing around with these projects beats watching Two and Half Men reruns or the Lakers getting their rears handed to them in the Finals.
 

BrueThru

Sentient Being
Elite Member
Last edited:
Y

yellowfz

Which bike ?

This is what I'm dealing with -- should be strong enough. I've hung more on less.
Yep that will probably do the trick , bout the only way to do it is add some thicker metal but just can't bring myself to weld to the swingarm .
Is this the 1200 or the 650 you are working on ?
 
Last edited by a moderator:
Less is More

Is this the 1200 or the 650 you are working on ?
The SV comes in either a 650 cc or a 1000 cc displacement. This is the far more popular and better received smaller of the two. Actually, this is the first sub-750 cc motorcycle I've owned since my very first motorcycle back in 1983. And I haven't even owned anything less than a liter bike in fifteen years. Refreshingly nimble this little guy is.

Funny, since my search for people talking about these rear fender splashguard things landed me here to the mythical world of all things FZ6R, I've really been looking at these bikes of yours.

Even though I've owned several Yamahas (first FZ750 back in '85/'86, two more FZ750's, an FZR1000, and the R1) and I sold bikes (Suzuki, Honda, Triumph, Victory) for four years, the FZ6R totally slipped under my radar. Now, I'm kind of itching to do my R1/SV street fighter treatment to one of these. Prefer inline-4 bikes anyway.
 
Y

yellowfz

Which bike in sig ?

The SV comes in either a 650 cc or a 1000 cc displacement. This is the far more popular and better received smaller of the two. Actually, this is the first sub-750 cc motorcycle I've owned since my very first motorcycle back in 1983. And I haven't even owned anything less than a liter bike in fifteen years. Refreshingly nimble this little guy is.

Funny, since my search for people talking about these rear fender splashguard things landed me here to the mythical world of all things FZ6R, I've really been looking at these bikes of yours.

Even though I've owned several Yamahas (first FZ750 back in '85/'86, two more FZ750's, an FZR1000, and the R1) and I sold bikes (Suzuki, Honda, Triumph, Victory) for four years, the FZ6R totally slipped under my radar. Now, I'm kind of itching to do my R1/SV street fighter treatment to one of these. Prefer inline-4 bikes anyway.
I am sorry in your sig it states SV650 and K1200R as bikes you own , just wondering which one the hugger was for , I will assume the SV650 from the comment .
Inline 4 is the way to go .
I think a lot of people would welcome your Street Fighter version of a FZ6R .
Storming today so work on project is stalled , but got everything welded up . Have flap ready to mount to the bracket , everything is solid when tightened and I do believe the thing will withstand the rigors of a road trip .
More to come tomorrow , hope to have finished piece and get some opinions from y'all about what you think and design of the flap .
I was not happy with angle to tire and changed it , but I believe now it looks much better , tilted (using heel , toe analogy ) the heel out some , looks better .
Found this while looking at SV650 pics ; http://www.google.com/imgres?imgurl=http://www.sv650.org/gallery/pic29/SV650N%2520equipee%25203.jpg&imgrefurl=http://www.sv650.org/sv_may03.htm&usg=__pZCoaj2BD9TSVdoRx9IbbUun2HE=&h=768&w=1024&sz=249&hl=en&start=30&zoom=1&itbs=1&tbnid=9kVoSYIliwGWKM:&tbnh=113&tbnw=150&prev=/search%3Fq%3DSV650%2Bpictures%26start%3D20%26hl%3Den%26client%3Dopera%26hs%3DaUG%26sa%3DN%26rls%3Den%26channel%3Dsuggest%26ndsp%3D20%26biw%3D1024%26bih%3D668%26tbm%3Disch%26prmd%3Divns&ei=GevKTa3REYHx0gGwg9zuCA Look about 2 or 3 sections down .
 
Last edited by a moderator:
My Mistake

I am sorry in your sig it states SV650 and K1200R as bikes you own , just wondering which one the hugger was for , I will assume the SV650 from the comment.
Sorry, man, I misunderstood you. Yes, I have both the bikes listed in my sig; I'm working on the SV though. I thought you were asking which of the two SV models I owned.

K-bike is great, but so frickin' expensive when anything mechanical happens. BMW makes it nearly impossible to work on your bike yourself unless you have their very specific, BMW tools to do it. So, it's going soon. And in defense of twins, no inline-4 can beat the remarkable engine breaking on these things. Nothing. However, and it may seem petty, but I've never liked the sound of twins. Really though, that's the only negative for me. And, pound-for-pound, twins get crappier mileage. But the sound element is big because you have to live with that note every time you ride.

Like the other folks, I'm really looking forward to hearing how the maiden voyage goes with your contraption. Obviously, pics, too. As for my project, I've been working on the solo-seat piece for the last two days (translation: the last two hours I've spent on it), but will get back to the fender tonight.
 
Phase 2 Complete

Not that these are particularly interesting, but I just wanted to keep my part of the thread alive with a quick update on how my SplashGuardRearFloatingFender thing is going. First shot is of the two-parter plaster mold curing on the back of the bike. The second shot is of the two pieces sitting on my workbench. My terrible photography skills prohibit you from seeing any details, but the molds turned out rough (for all sorts of reasons attributed to my minimal experience in all this), so I have some patching and sanding still to do on them. That's one of the great things about this craft; during almost every phase of it there is opportunity to fix your mistakes -- or at least lesson their impact on the finished product.

After the patch job, I prep for the fiberglass, then it's on to the gooey, flesh-burning, toxic fun part -- the laying of the fiberglass cloth.


 

Y

yellowfz

On my cell , but looks good so far. Caught the flu, but did get to ride short trip, worked as expected. Need to make couple adjustments before showing final shot.
 


Top