Author Topic: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)  (Read 56195 times)

Offline hallin222

  • Posts: 163
  • aka: HonkyKong
    • HonkyKong Customs moto-art
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #10 on: Jun 13, 2012, 01:28:18 »
Custom fork brace pics below.  Note that I didn't create this from scratch.  The dual arch brace was acquired along with a bunch of other parts, many of which came off 70's era enduros, I think.  This was just too cool of a piece not to use, so I made that center rib from a chunk of 1/4" aluminum plate, that was then rolled (via the help of fresh_c) to the approximate radius of the tire.  I tapped the two mounting holes for metric fasteners for bike consistancy, then drilled it full of holes and sanded it smooth for asthetics.

However, the pre-existing fork mounting hole locations and side plate width didn't exaclty fit the KZ forks, so I cut up some side plat spacers (barely visible in pics) out of 1/4" aluminum plate on each side.  Also, with the 1/4" strip now mounted UNDER the arches (which I love the look of), the center rib grazed the tire slightly.  If that happened when stationary, It would cause a problem at speed, so I slotted those holes with a round file to allow the assembly to sit a little higher off the tire.  I hope there is enough clearance.

It's a pretty close fit here.  Should I have any concerns about tire 'growth' at speed?  Also, ignore that ugly right fork leg.  It will get sanded down before this project is all done.

Feedback is welcomed.  Keep it coming.  I have a few stylistic ideas for this bike, but am open to suggestions.

Offline sinbad85

  • Posts: 330
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #11 on: Jun 13, 2012, 07:59:47 »
wholly shit dude that is one AWESOME looking fork brace!!

just dont plan on going riding in the rain.....(although we never actually "plan" riding in the rain now do we?) haha

well done!
i was going to bend something up out of some 8mm or 10mm steel rod. but i dont think it will look anywhere near as good as that!
has certainly given me some ideas!

the only thing ide be concerned about is the clearance... at say 80mph or above the tyre is going to have a massive amount of centrifugal force on it thus trowing the tyre out.....
just hope it dont rub!!

Offline hallin222

  • Posts: 163
  • aka: HonkyKong
    • HonkyKong Customs moto-art
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #12 on: Jun 13, 2012, 11:15:08 »
It's been brought to my attention via PM that this is not the world's stiffest design, as it's more of a fender mount, really, which I'm aware of.  It'll never behave like a true brace, and I'm ok with that, considering I was going to run no fender or bridge of any sort until I stumbled across this part.  Honestly, I just think it looks cool.  There is also the possibility of me raising it of the tire another 1/8" or so if absolutely needed, but there is no need of running it 1-3/4" off the tire as was suggested via PM.  No STOCK fender even sits anywhere near that high.

Perhaps I should have called it a "custom decorative fork treatment" or something more appropriate.  This was done 90% for asthetics, rather than performance.  I'm not looking for the fastest, best handling, best braking bike here, just a fun, cool looking cruiser that I'll be proud to have built myself.  If I were after all-out performace, I wouldn't have mounted up those Firestones, or chosen a heavy 30+ year old motorcycle as my foundation.

There is also concern (from others) regarding the lowered forks.  While I may lower it 'properly' via shorter, stiffer springs, the ride height viewed here isn't that low and has no frame or header clearance issues with the front tire.  I would like to stiffen the front end though, so if anyone knows of another model's springs that might fit my needs, please chime in. 

Offline JRK5892

  • Posts: 9755
    • The Powder Pro
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #13 on: Jun 13, 2012, 14:31:31 »
really a good looking build so far
"your life is an occasion, Stand up to it"

recent builds: Hd street bob, TX cafe, KZ bratt, Goldwing tour, bratt wing, st fighter, road king, vriago bobber, chop, FXD, 1200 sporty, 1200xl sporty, GSXR, Royal enfield.. and more

Offline rays650cafe

  • *
  • Posts: 696
  • No quarter given, none taken.
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #14 on: Jun 14, 2012, 00:42:12 »
Seriously good stuff goin on here. I have concerns about your fork decoration being so close to the front tire. I don't know ya, and it wouldn't concern me as much if it were over the rear tire. But I have been over the handlebars at high speed. It sucks. I got lucky,me and my bike landed in the soft stuff. i just hope you reconsider the extra 1/8 inch before you "see" if you need it. Guessing those old school tires grow at speed. If it were the rear tire in question, I figure it would just flat spot at worse,add a little excitement to your ride. Thats the front, That could ruin a tire and a pair of underware. Just my .02 nice build,good riding.
High functioning sociopath.

Offline hallin222

  • Posts: 163
  • aka: HonkyKong
    • HonkyKong Customs moto-art
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #15 on: Jun 14, 2012, 01:13:21 »
I'll consider it, but it doesn't appear to be any closer than what is seen here:    ...but maybe that closeness is allowable with a radial tire.  (?)

My bike is far from being operational, so I have plenty of time to adjust it.  Notice no brakes, no wiring, and that tank is just a rusty, dented junker being used for visuals and general mock-up.

Next up will be some info on the battery tray and seat pan I'm working on.  I just haven't uploaded my photos to my hosting site yet. 

Offline casper3043

  • Posts: 50
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #16 on: Jun 14, 2012, 03:45:58 »
love this thing mang! style is really close to mine. keep up the good work and keep us updated.

Offline warpedworm

  • Posts: 362
  • I could agree with you but then we'd both be wrong
    • Warped Worm
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #17 on: Jun 14, 2012, 16:23:33 »
Nice build :)  I'm a big fan of the Kawi twins, although mine are much smaller.
I hope to build up a 750 someday.

Really like the looks of your bike.
'83 Gpz 305 Cafe"Lorelai"

Gpz 305 (Restoring) "Jett"

Gpz 305 Dragbike/LSR "Derelict Dragon"

Gpz 305 "Fetish"
Gpz 305 ?
'85 Cagiva 650 Alazzurra "Sadie" (My Italian Girl)
'96 Muz Skorpion Tour "Dagmar"
'01 Yamaha TW200
'00 Ducati ST2  "Lola"  (My Italian Lady)

Someday when the Stars & Money align:
Cagiva Mito/Laverda Sport 750/
'86 Ninja 250/Any Moto Morini/Ducati SS 750/
Any Ducati Single/Cagiva Alazzurra 650 Cafe/
Derbi GPR 50

Offline hallin222

  • Posts: 163
  • aka: HonkyKong
    • HonkyKong Customs moto-art
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #18 on: Jun 16, 2012, 10:01:28 »
Here are a few shots of the electrical tray I made.  I first took a few measurements of that area of the frame, then modeled this sheet metal part in SolidWorks.  This allowed me to print the flat pattern of the part and test-fit it as a cut and folded paper sample (see previous images).  When the paper box seemed to fit about like I wanted it to, I went about cutting out the flat pattern out of 1/8" aluminum sheet.  This was overkill, and I could have used a much thinner material, like .070" or something, but this box will be extremely dent resistant over its lifetime.

The forming of the box was actually pretty difficult, given the manual brake (sheet metal bender) I had access to, and the complexity of multiple internal bends.  Again, since I have no ability to weld aluminum, I riveted the corners together.  I actually prefer this look to welds anyway.  DTT member, fresh_c helped me form and rivet this, as my bends weren't perfect and it took some C-clamps and muscle to get everything to line up before drilling and riveting. 

If I can find some images of my flat pattern, I'll post those up soon too.

These mounting tabes were originally made quite oversized, but I waited until I held the box up under the bike frame to trace the tab arcs, and mark the holes, to ensure proper alignment, before finishing their trimming with a Dremel and hand files.  The bolts currently installed (up from the inside) are too long, but will be replaced with some with shorter thread shafts, to sit flush with, or below the top plate, as to not make contact with my custom seatpan.

First shot of seatpan.  This is .070" aluminum, if I remember correctly.  I gave it a slight kink down the centerline to give it a little rigidity before making the other two bends to fit the frame properly.  I'll get some better pics up soon.

Now, because I'm a larger guy, and I may end up running 1" shorter shocks in the future (maybe not, we'll see) I wanted to check tire clearance through the full range of motion, so I removed the shocks, slid the rear axle as far as it could go forward in the axle plates, and lowered the bike on the jack until the tire made contact with something.

Although it hits the rear of my electrical tray before touching my rear frame hoop and tail light / license plate mounting tab, it's unlikely that this will ever occur in practice.  If I move the axle back 1/2" in the axle plate (usually required to attain proper chain tension) the electrical tray clearance problem disappears, and the concern becomes the rear frame bar, at the 12:00 position over the tire.

My next step is to cut out the necessary area of the seatpan's rear section, and create two crecesnt / wedge shaped side peices and an arced inner fender to create a bump for tire clearance, much like old drag racers would 'tub' their rear wheel wells to make room for big, wide, tall slicks.  This will also be riveted together, with the heads of the rivets only being visible from under the bike, and maybe slightly from the rear, but unlikely once the tail light and licensce plate bracket are installed. 

Offline sinbad85

  • Posts: 330
Re: Project: "HonkyKong" 1979 KZ750 B Twin (brat-tracker-thingy)
« Reply #19 on: Jun 16, 2012, 22:53:32 »
awesome seatpan dude!!!!