Author Topic: 1978K Resto-mod "HaCkJoB" (Read 23971 times)

shinyribs · « **on:** April 29, 2012, 09:38:17 PM »

I just picked up this pile of parts a few weeks back. I am slowly collecting parts. I want something that handles well with modern-ish suspecsion,a smooth ride and room for storage. But the main thing is it HAS to be easily spotted as a CB. Nobody ever knows what my current bike is it's getting old.

I have no idea how this will turn out...I guess we'll just have to see...

PART_1334428586681 by Shiny Ribs, on Flickr

PART_1334441133108 by Shiny Ribs, on Flickr

Aah,a pristine frame to begin with! So glad the PO took such good care of it

. Oh well,it's that much less I have to cut off.

PART_1334446846047 by Shiny Ribs, on Flickr

This project WAS going on hold until this winter,but then I won this baby off eBay for cheap...so it begins!

ebay swingarm by Shiny Ribs, on Flickr

kerryb · « **Reply #1 on:** April 30, 2012, 09:56:10 AM »

That should be neat! With the rear suspension mounted inboard, you will have more room for the inside edge of your bags. you'll be able to carry more stuff on the pro-tour.

I've been daydreaming of an airfoil-shaped top box Being a k8 fan, I notice you don't have k8 tanks there.

jsut for fun...kerry

shinyribs · « **Reply #2 on:** April 30, 2012, 04:09:09 PM »

Calling it Pro-Touring may have been misleading. I am a car guy,and am new to bikes.I know what we car guys call Pro-Touring,the term may not apply here. The main reason for running the mono-shock,besides hopefully improved ride/handling,is to gain extra room for the pipes.I wanna run two down each side then kick them up in the back right under the tail piece. There may be bags on this build,not sure yet..I'm not crazy about the look of bage,but you goota have 'em.Thats one dilemma I havent solved yet....

shinyribs · « **Reply #3 on:** May 07, 2012, 08:18:31 PM »

Ok. I had to rename this thread. As with vehicle I build the name of that car/truck/bike comes along when something during the build happens. I joined a ZX owners forum in the hopes of finding someone kind enough to measure their bike for me so I could have some sort of clue as to how to mount this swing arm and shock. Here is what I got:

"I would just stop and reconsider what your attempting to do. If the bike already has a complete suspension then just leave it be, if it isn't broke don't fix it. Should it indeed be broken or missing, replace with the original parts. Its gonna be a hack job like no other to adapt."

Ok! HaCkJoB it is!

shinyribs · « **Reply #4 on:** May 07, 2012, 09:11:13 PM »

She's up on the table,but yet to be jigged into place. Fits in the frame well. I need to locate dust covers for the pivot end,then I can measure for what spacers are needed.

SANY0058 by Shiny Ribs, on Flickr

SANY0050 by Shiny Ribs, on Flickr

SANY0056 by Shiny Ribs, on Flickr

I dont suppose anyone one here owns a 85-87 ZX600,do they??...

shinyribs · « **Reply #5 on:** May 22, 2012, 08:36:35 PM »

I got the rear suspension all finished tonight.It's not burned it permanent yet in case I need to move a tube for any unforeseen clearance issues,but I think it'll be OK. I got the hoop for the upper shock mount tied into the main backbone just like I wanted it. Now to start on the rear sub frame. I dont know if I want to make it removable or not. If I use aluminum like I originally planned it will definitely be removable,but not sure if all that is necessary or not. I could really use a brainstorm right now,but it just ain't happenin'. I know it looks like a big greasy mess right now,but i'm just getting everything tacked in for now. After that is all done I will sandblast the frame and burn everything in tight

SANY0114 by Shiny Ribs, on Flickr

SANY0108 by Shiny Ribs, on Flickr

SANY0117 by Shiny Ribs, on Flickr

Messenger750 · « **Reply #6 on:** May 22, 2012, 09:23:23 PM »

*Following*

benjy · « **Reply #7 on:** May 23, 2012, 11:20:20 AM »

like that mounting.gives an extra bracing near s/arm pivot too.neat.

OneWheelDrive · « **Reply #8 on:** May 23, 2012, 01:43:08 PM »

Yup, following. Looks interesting so far!

shinyribs · « **Reply #9 on:** May 23, 2012, 02:57:42 PM »

LOL! Thanks for the interest...but i wouldn't get your hopes up too much. So far everything has been a breeze.Which means something is bound to go horribly wrong!

shinyribs · « **Reply #10 on:** June 10, 2012, 08:17:28 PM »

Ok,I got some piddling done.And acquired a few new parts. Aaand revamped the rear area of the frame tubing. That allowed me to get all of my tubing tied into the backbone like I wanted. Including the rear legs of the cradles. I am still undecided how to go about tying in the front portion of where the cradles met the neck,or if I even will. Any suggestions here would be much appreciated.
I am going to be using a front end of an '81C DOHC bike. It didn't take much to get the early SOHC Comstar to fit up. The rotors were a dead bolt-on to my wheel and the axles are the same diameter. So that part was a breeze. The forks sit wider with the DOHC trees ( which are a dead bolt-on with a tapered bearing setup) so that needed attention. I shaved 1.5mm off of the speedo drive housing and added a 12mm long spacer to the opposite(left) side and it centered perfectly. I like the Custom forks with the drop down fork bottoms.It helps with the semi-offroad look I am shooting for. Also,with the axle in front of the fork, rather than centered under the leg,it gave me another 1 1/2'' of wheel base.That coupled with the ZX swingarm gives me a 62 1/2'' wheelbase which is 4'' longer than my '76 F. :)I like that.

Speaking of suggestions. The XR seat I plan to use is much narrower than I expected.It is only 5 1/2'' wide at the front

I am not sure which tank I like it better with,or if I like either one of these tanks with this seat.Opinions,please?!

SANY0122 by Shiny Ribs, on Flickr

SANY0121 by Shiny Ribs, on Flickr

SANY0128 by Shiny Ribs, on Flickr

SANY0127 (2) by Shiny Ribs, on Flickr

This is where I am currently on the tubing. I am at a stand still until my carburetors arrive so I can check for clearance issues between them,the tubing and whatever tank I decide to go with.And yes,every tubing joint did get a slug.

SANY0177 by Shiny Ribs, on Flickr

SANY0176 by Shiny Ribs, on Flickr

Nothing is finish welded right now. I am still trying to figure out all my mountings before I go too far. I can fit all my electrics under the tank and the battery under the XR tail. If the electrics DO end up under the tank I will still want to mount the fuse block in a more accessible area. You know how roadside repairs happen

I need to figure out where the oil tank will go. I have considered using a portion of the fuel tank but thought it would be a little warm on the crotchal areas.Plus,heated fuel is not the best thing for making power

Also,these bikes are top heavy enough.No need to mount that weight any higher than necessary . What do y'all think about running it through the swing arm? It is hollow and completely closed. There would be a fair amount of plumbing required for that,but that is not a problem. My main concern with that is if it would hold enough oil. Oh well,still lots of particulars to figure out but that is all the fun of it.

shinyribs · « **Reply #11 on:** June 10, 2012, 08:22:45 PM »

Ya know,it's too bad I am not building a bobber. That short frame sure would make for a clean looking bobber

Retro Rocket · « **Reply #12 on:** June 10, 2012, 10:31:01 PM »

You will have some strange handling there Shinny, look at the extra length at the rear of the bike, its about 5-6 inches longer than stock.
I'm using a GSXR1100 swing arm on both my bikes but with the mono shock removed and the arms shortened to be close to the stock dimensions.

shinyribs · « **Reply #13 on:** June 11, 2012, 03:49:46 PM »

Thanks for keeping an eye on me,retro rocket. The swing arm looks much longer than it really is. It is mounted in the stock location and it is only 2 1/2" longer than the stock '78K s-arm that was originally on the bike. Basically,if you adjust the wheel to the furthest rear point on the stock arm it is in the same position as the ZX arm with the wheel all the way forward. Did I make that clear as mud?LOL.

I have heard both good and bad about extended swingarms. Some say it will ride smoother and some say it will be hard to lean.others say they see no difference. Do you think an extra 2 1/2" will throw me off that much? Thanks for your suggestion,too! I need all the help and ideas I can get!

Retro Rocket · « **Reply #14 on:** June 11, 2012, 04:16:18 PM »

Quote from: shinyribs on June 11, 2012, 03:49:46 PM

Thanks for keeping an eye on me,retro rocket. The swing arm looks much longer than it really is. It is mounted in the stock location and it is only 2 1/2" longer than the stock '78K s-arm that was originally on the bike. Basically,if you adjust the wheel to the furthest rear point on the stock arm it is in the same position as the ZX arm with the wheel all the way forward. Did I make that clear as mud?LOL.

I have heard both good and bad about extended swingarms. Some say it will ride smoother and some say it will be hard to lean.others say they see no difference. Do you think an extra 2 1/2" will throw me off that much? Thanks for your suggestion,too! I need all the help and ideas I can get!

It generally slows down the bike wanting to turn in to a corner, the way bikes are set up is that the front and rear are balanced to a degree so they both have similar characteristics as far as turn in is concerned, the late K's had a longer swingarm than the earlier models already. What happens is that the front being stock will stay the same, the rear will react a little slower because of the added length, this would be more noticeable when riding hard in the twisties, if you don't really push the bike at all i don't think it will be that noticeable.... It is generally accepted that an inch or so longer doesn't do much except add a little stability in a straight line, lots of racers add slightly longer arms to these bikes. I like the look of the Yammy tank mate, i have seen another 750 with that tank and it looked great....

shinyribs · « **Reply #15 on:** June 11, 2012, 08:47:37 PM »

I like that tank,too.Thanks for the input. I might just mount it tomorrow

Thanks for the info,too. I am wanting this bike for longer rides because my Cafe is not all that comfortable...go figure.LOL. So what you are telling is it won't be a corner carver,but the added length on the swing arm will make it more stable while cruising?I'm ok with that.

Since this bike is stretched on both ends would it balance out,or have I really screwed up?

Thanks again for your info. I am learning as I go on this one. I do not mind cutting off mistakes either

shinyribs · « **Reply #16 on:** June 11, 2012, 08:55:00 PM »

Hey Retro,is there any chance that you know what this Yamaha tank came off of? I dont have a clue

Retro Rocket · « **Reply #17 on:** June 12, 2012, 02:09:26 AM »

Quote from: shinyribs on June 11, 2012, 08:55:00 PM

Hey Retro,is there any chance that you know what this Yamaha tank came off of? I dont have a clue

late 70's XS 750 Yamaha triple.

You say "stretched at both ends", what's done at the front.? It will still go round corners mate, just take a little more effort to get it to turn in. Its funny how frame geometry works Shinny, if you were to use a later model front end with less offset {like the GSXR's and the like} on the triple clamps it would lengthen trail, slowing the front end response as well. It can be tricky getting the balance right but if you don't mind playing round with things just build it as you are then work out what you would like to change later on.. Personally, on the K model 750 i am going for an inch longer in nthe swing arm and 10mm less in the triple clamps for slightly more trail, it should settle the handling down just a bit and add some stability, unless you pus the bike you probably would never notice it at all... I can't help myself mate, i am always playing round with things and altering to my taste...

shinyribs · « **Reply #18 on:** June 12, 2012, 11:59:40 AM »

It's off an XS?!?! Aw crap! I bought it off a guy at a flea market for $20. He said it came off a what he thought was a Virago. He said it was a funny 3 cylinder bike. I didn't know anything about it and passed on the bike when he said Virago. He said it was running but the backbone cracked and he would sell it,title and all,for $250. LOL I wish I hadnt asked where the tank came from now

Retro,what I meant by stretched at both ends is the front forks and triples have been swapped for an DOHC '81C front end. You can sorta make it out in the pics,but the axle sits in front of the fork sliders rather than under them.It measures 1 1/2'' longer than a standard SOHC setup in regards to wheel base.

Thanks for the info on the tank,even though it made me sad :'(LOL

shinyribs · « **Reply #19 on:** June 12, 2012, 09:04:33 PM »

Piddled on the seat some tonight.I decided it needed an inner structure rather than letting the fiberglass support my fat butt. Used some 5/16'' steel rod I have left over from making throttle linkages and the remainder of the sign I cut up for my tail fairing on the other bike.

Aluminum spacers to protect the fiberglass from the tack welds and also to space it out so the pan will fit just right.

SANY0016 by Shiny Ribs, on Flickr

SANY0022 by Shiny Ribs, on Flickr

SANY0024 by Shiny Ribs, on Flickr

SANY0023 by Shiny Ribs, on Flickr

I also got the tank mounted.I learned on mounting my last tank how hard it is to get each peg just right when doing the front mounts. I got smart and made it easy on myself this time. I drilled thru the backbone and drove a single peg thru.Presto!Both sides match!

SANY0002 by Shiny Ribs, on Flickr

SANY0010 by Shiny Ribs, on Flickr

SANY0011 by Shiny Ribs, on Flickr

SANY0015 by Shiny Ribs, on Flickr

Retro Rocket · « **Reply #20 on:** June 13, 2012, 01:01:54 AM »

If it helps Shinny, those old XS yammies weren't too bad of a bike, i have a soft spot for the old triples. So who cares anyway, use the tank, it looks cool....

shinyribs · « **Reply #21 on:** June 13, 2012, 08:13:36 PM »

Ha! No,that doesn't help at all.

I googled the bike and really like the looks of it. Too late now!

Mtmooradian · « **Reply #22 on:** June 13, 2012, 08:23:52 PM »

Nice work, I'm using the same swing arm for mine.

shinyribs · « **Reply #23 on:** June 13, 2012, 11:54:09 PM »

Thanks. i checked out your build...now I'm ashamed of mine :-[LOL. Your bike looks great.Looking forward to seeing it finished !I was gonna ask how you worked out the 20mm rear axle and chain adjusters,but saw you went with the original size. I am having a heck of a time getting someone to make me an axle. I am borderline on just biting the bullet and buying a lathe.

Toxic · « **Reply #24 on:** June 14, 2012, 03:33:11 AM »

Quote from: shinyribs on June 13, 2012, 11:54:09 PM

Thanks. i checked out your build...now I'm ashamed of mine :-[LOL. Your bike looks great.Looking forward to seeing it finished !I was gonna ask how you worked out the 20mm rear axle and chain adjusters,but saw you went with the original size. I am having a heck of a time getting someone to make me an axle. I am borderline on just biting the bullet and buying a lathe.

Give member 754 a ping, if he can't make you and axle, I'm sure he can point you in the right direction. Great knowledgeable guy.

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Author Topic: 1978K Resto-mod "HaCkJoB" (Read 23971 times)