1977 GS750B - my long awaited first bike!

[gearheadE30]

Just a word of advice on using the insulation as muffler packing - I did almost the same thing you did for a baffle. It sounded great too, but one night after a long relatively hard ride on some good back roads, I pull up to a stop and see flickering light coming from behind me. I look back and there were flames coming out of the exhaust. Turns out I caught the insulation on fire running hard. I've since made some internal metal baffles so I could get rid of the packing, which also seemed to help with the midrange. Even jetted correctly, pre-chambered-muffler, the powerband was an awful lot like a 2-stroke.

[Chuck78]

Updates!

Trying to stay focused on working on the house remodel while getting really excited researching and compiling parts for both of our bikes. I have a really killer setup waiting thus far.

I stripped a ton of parts off of a GS650G for her GS550 engine top end upgrade, and the non engine stuff for my bike, thanks to Rice Paddy Motorcycles - our saviour here in Columbus, OH - all Japanese mostly vintage motorcycle junkyard!

Here you can see the 35mm GS650 dual disc air/oil shock front forks that I got to upgrade from my single disc setup, as well as a healthy pile of parts that will soon transform my GS750 into a really great handling and powerful beast! Honestly with the Wiseco 10.25:1 844cc kit, it's already a powerful best... going 920cc 10:1 will give it a little more grunt and make for a unique build!

[Chuck78]

Updates

Here is the direct drop in OEM big bore setup, first year 1979 GS850 jugs! 80+ would work with a little bit of dremel action on the crankcase. These cost double but will be less work.
Then there's the out of production MTC Engineering 72mm GS750/850 920cc big bore piston kit. They were 10.5:1, and I was worried about 87 Octane in the summer as well as overheating. MTC said they could shave .040" off the domes and drop it a little more than a half point to just under 10:1 compression, and it should be fine with pump gas in Ohio summers.

[Chuck78]

Updates

There's the GS1100E extended aluminum swing arm underneath, and the top portion of the GS650G triple clamp and zero rise handlebars that were on that bike at the junkyard.

The triple clamp has the ignition switch assembly built into it, where my GS750 has it built into the ugly factory gauge housing that I am ditching. The 650 triple clamp top has higher handlebar mounts to clear the air fill schraeder valve top caps.

I wanted to go lower than the superbike bars that came with my bike, and this combo will drop me about 1-1/4" and allow me to keep the ignition switch up top when running 2.5" chrome mini-gauges. The lower triple clamp on the GS750 has a fork lock, so I am keeping that. I thought about clip-ons, but not sure about long distance comfort and pressure on my hands on a several hour ride or long road trip, especially with a bum wrist that acts up every so often. Being on the highway however, I always feel like I need to be lower and more forward. Clip-ons and the massive 5 gallon GS gas tank may be too much, as I have read.

[Chuck78]

Updates

MAJOR THANKS TO DAN AKA SALTY_MONK for the brake inspiration, otherwise I would be running heavy GS650 factory duals with single piston calipers! Here are a nice pair of Tokico twin piston calipers that I am going to modify to fit our bikes without any adapter brackets. Dan makes a nice bracket bolt and spacer kit available for members that does this as well.
I have two extra caliper brackets from the junkyard. I will be chopping them in half and grinding them to fit, and then welding them onto the real caliper brackets as an extension to get the caliper in the correct position, probably utilizing the same threaded hole in the chopped in half bracket piece. I got the extra brackets so I wouldn't have to source this exact thickness of metal barstock to keep the caliper bracket perfectly aligned while clamped in a vice and welding it.

I was really looking for some CB600F Hornet aka "599" rotors (also on many CB400 models thru 2005) which had our oem 22mm offset and 78mm 6 bolt PCD, but I could only find new chinese rotors for $225 a set. I settled for a set of older CBR900RR Fireblade rotors that have the correct 6 bolt 78mm PCD but the standard 17mm offset. I will probably buy spacers from Dan to put the rotors where they need to be, or possibly use some scrap metal to add a spacer to the fork mounts to push the calipers over 5mm. This is ok on spoke wheels, but on some mag wheels, this will not have any clearance. I am still debating on additional leverage/flex from moving the caliper away from the center of the fork, which makes me consider the hub/rotor spacers more since the GS hubs take 6 massive 8mm bolts to hold the rotor on, no worries about bolt extension being torqued on too hard.

There you will also see a 2005-ish Ninja 600(EX?) Nissin brake lever and master cylinder, since I hated the plastic reservoir stockers, and I needed to upgrade to the larger diameter dual disc master anyways, 5/8" or 16mm instead of 1/2" or 14mm for single discs. These have a leverage dial that makes the brakes spongy but really grippy all the way down to rock solid lever but less total clamping force, makes it nice to dial it in to the feel you want. AND this thing is like brand new! EBC pads to go with the calipers also.

[Chuck78]

FINALLY, I don't have to pay Woody's $514 to have them lace up a used GS750 hub with stainless steel spokes and nipples and a new DID 3.50x18 aluminum rim!!!!!
http://http://www.ebay.com/itm/150960689420

Been searching ebay for a while. Missed out on a $120 and $170 3.50x18 36 spoke rim, but finally found a deal! GS1000/1100 rear wheel off of a GS1150 drag bike with GS1100 engine. It's the correct 36 spokes and Suzuki bolt pattern on the rotor, must be an older GS1000 wheel? 1100's and 1150's were almost all mag wheels as far as I've seen.

I will probably get a new Excel 2.50"x18" front rim next, give my wife my my nice clean 19" front wheel, ditch her rusted GS550 spokes and rim to relace her front hub into my new alloy rim with some stainless spokes. In the future, I'll relace this new used rear with stainless spokes and polish the hub on a buffing wheel while I'm at it.

[Chuck78]

Also purchased the upholstery to re-do my seat, $30-ish on ebay with a layer of foam padding sewn into the vinyl already with lateral pleats going across where it's sewn. I will be shaving down my seat foam flat (ditching the rear high rise portion) by reshaping it with a 4" angle grinder. I may get a bicycle gel seat cover, and cut a recess into the foam to insert it in the driver position. rear of seat will be minimal. I had considered going solo seat and getting rid of the passenger footpegs and exhaust mounts completely and leaving the fender exposed with some bracing to support a set of saddlebags, as well as ditch the GS trunk. I will swap my battery for one half the size, lower the battery box as close to the swingarm as I can, and then build an aluminum box where the battery was as a storage compartment under the seat.
I had even contemplated removing the battery, starter, and starter gears to save weight, but I would have to add a big capacitor to where the battery terminals hooked up to act as a cushion to the charging system, so I figured I'd just use a smaller battery even without a starter, to give the ignition a little more firepower when kickstarting cold.

[Chuck78]

Other than just wanting alloy rims on my spoked wheels, I wanted to upgrade rims so that I can run wider than a 110 or 120 rear tire safely without poor handling from the tire squeezing into a narrow rim and flexing massively in every turn.

From reading GSR members' feedback and the love for the Avon AM26's and bargain priced Shinko 230 Tour Masters (formerly Yokohama treads and compounds), I have so far narrowed it down to:

Shinko SR741 rear
$77 140/70/18 (5.4" wide and 26" diam)

Shinko 230 Tour Master fronts
$81 120/90/18 (4.69" wide 26.5" diam recommended 2.75" rim but same size in Avon says 2.5" or 3" rim)
$67 110/90/18 (4.29" wide 25.79" diam recommended 2.5" rim)(much smaller than the same size in Avon's)


or the slightly more expensive Avon's with really great customer support, wide variety of sizes available:
Avon AM26 Road Rider rears:
$147 140/70/18 5.6" wide 26.2" diam (3.5-4.5" rim, 3.75 is best)(closest to the stock 26.4" diameter)
$115 150/70/18 6.1" wide 25.9" diam (3.5-4.5" rim, 4.25 is best - very close to tire, 150+ I'd say need offset sprockets)

Avon AM26 Road Rider front:
$109 110/90/18 4.6" wide 26.1" diam (closest to stock 26.1" for speedo accuracy)


These tires are all V-rated for speeds up to 149mph / 240kmh. The Shinko's are a great bargain, although I have not read of anyone here running the SR741, but the highly regarded 230 Tourmasters were not available in the rear size I wanted.
The Avon's are a very reputable brand and the Roadriders are a very appraised tire, and I may go with them if I have the extra cash. They also run a bit wider, so I will have more tread contact on the road. The rear tread seems to have a nicer radius on it for turning in quickly as well. But I will drop $100 more on them approximately.

I am really trying to shoot for a bike that holds the corners as well as a lot of modern sport bikes, has plenty enough modern braking technology to slow it down in a hurry (and save weight on the Ninja brakes vs the original Suzuki factory duals), and handles the bumps and twisties really well.

[Chuck78]

Now I need to get some Hagon 2810 ($299) or Ikon ($379 but rebuildable) adjustable dampening rear shocks 13" eye to clevis. I may save this for last since it is an easy bolt-on.
Before i do the dual disc upgrade, I will be putting some Sonic or Progressive brand springs into the forks and rebuilding them with new seals and bushings.

I had considered going with some RaceTech cartridge Emulators for $200, but I am going to hold off for now I think.

Also saving up for a VM26 carb o-ring kit, new gaskets and needle and seats, and appropriate main jets and jet needles according to some very well researched help from 49er. Those K&N RC2222 dual oval filters will eventually make it on here, and I will be removing the MAC 4-1 exhaust and de-rusting it, chopping it and bringing it about 3/4" closer to the bike height-wise, and wrapping it with black header insulation wrap to keep the engine seeing fresh cool air as much as possible to keep it running cooler with the higher compression pistons. Homemade baffle and MAC muffler shell will probably remain unless I find a deal on a V&H setup.

I was also tipped off that a GS1100 2 valve replacement head gasket has the 73mm bore that I need to work with my 72mm pistons, and it is a Multi-Layer Steel construction, the best and most bulletproof of head gaskets! (Suzuki # 11141-49410)
Getting a GS850 base gasket, and freshening up the rest of the engine with new gaskets and seals, and a GS650 neutral detent spring to help me get into neutral better.

[Chuck78]

Also got a nice GS650G top end for Reda's bike, cylinder jugs, pistons, head, cams, etc. Looking for some 1987+ GSXR600 BST33SS flatslide "slingshot" cv carbs or maybe the BS32's from the GS650 at the junkyard. Just got that rear wheel for mine, so I can donate my rear disc wheel to hers and use the GS1100 rear discs that came with the GS1100 swingarm to convert her drum brake rear (poor stopping power) to a GS1100 disc!
Also got a CBR1100 Blackbird 310mm diameter 22mm offset 78mm PCD front rotor for her bike and a single Tokico (Kawasaki Ninja) twinpot caliper to upgrade hers! The single disc bikes had higher caliper mounts, and Suzuki_Don has sucessfully fitted a 310 rotor on with one of Salty's brackets to a single disc fork. Gotta have lots of stopping power for my the love of my life, especially since I will be hot rodding her engine to put out around 80+hp! That bike is going to be a real screamer, one of the best GS550's you will find

[T8erbug]

I have been creeping on a lot of your posts lately because it seems we have some of the same ideas going on. It also seems we do more research and part buying than actual building and riding! I hope things get rolling soon on your build because I'm excited to see those parts come together to make a complete bike. Let me know when you get that new aluminum wheel laced up because I'd love to see it. I have a 79' GS750 with a GS1100 swingarm I have yet to install due to my hesitance to drill out the frame.. I'd rather come up with a sleeve of some sort to make the conversion. Also I have bought 78' GS750 wire wheels because I wanted wire wheels with dual front brakes. I want to make them wider (at least the rear). I just finished machining hub spacers in the front to fit GSXR bearings and Triumph Daytona 955 320MM rotors. Let's stay in touch as our builds progress because I think we can probably help each other out. Keep up the good work

[Chuck78]

Getting some late winter and early spring mods rolling out finally, after accomplishing some decent progress on the house remodel. We are planning a mid-may White Water Rafting trip and 6 day motorcycle trip in the West Virginia and Virginia twisties and mountain ranges, so my wider tire/rim upgrades and dual disc front brakes became an urgent priority!


I'm a little more ambitious and a lot more broke than most people (due to massive 1892 Victorian home remodel that us bleeding me dry), but I got some Kawasaki Ninja/GS500 calipers and Honda CBR900 rotors and some extra scrapped caliper brackets from the junkyard, and am making my own twinpot mod setup with no need for caliper adapter brackets. I was trying for some CBR900 310mm rotors wwith 22mm offset, or some CB600F rotors in the few years they also had 23mm offsets, but those were too hard to find without paying $220 for a new Chinese set (no used ones in the 296 CB600F versions). I'll be making up some rotor spacers from aluminium with a top hat type centering flange to make up the difference from the 56mm hub to the 62mm rotor opening to keep them perfectly centered.





Still have to chop up a second bracket and file-fit and notch it to weld, this week I hope! Then I'll be using more parts of the chopped brackets to use my wife's single disc GS550 fork to fit a 310mm CBR900RR 22mm offset rotor on hers with a GS500 left side single front disc caliper (same as the Ninja's). The 310mm rotor on the single disc left fork leg requires a bit more distance to swing the bracket out, a little more fab work but still easily do-able for those good at welding and fabrication

[Chuck78]

GS400X gauge pods in favor of the giant plastic hunk of a dash console

Also got these awesome GS400X individual gauge pods in somewhat decrepit shape from a parts bike at Rice Paddy Motorcycles here in Columbus (my local heroes for used VJMC parts!), cleaned up the pitted chrome to almost respectable condition, may sand and clearcoat or just sand and paint black if the remnants of the pitting bother me too much. The faces were useable but faded with some oxidation bubbles making the paint rough in spots. I disassembled them and scanned the faces, now making my own faces converting to 130mph from 110 and adding an oil indicator light on the speedo if I can cram it in under the tripodometer drum!

[Chuck78]

Unlike most people who want wider tires and just cram too large of a tire on for what the stock rim width can handle (pinching the tire and ruining their handling), I picked out new aluminium rims in the best recommended width needed from the tire manufacturers to run the tire combinations I wanted. 140/70/18 rear and 110/90/18 front. Close in diameter to the stock 110/90/18 rear and 90/90/19 front. I could fit a 130-150 rear on and 100-120 front with these rim sizes (2.50&3.50), but staying right in the middle for optimal tire profile curvature as the tire manufacturers have designed them for. Also, swapping to aluminium rims from the stock chromed steel to drop enough weight to compensate for the bigger tires adding weight.

I picked up a nice used DID WM4 2.50x18 flangeless rim for the front, $50 used from a mid 80's Yamaha TT600. It was drilled for a large diameter rear hub, so I just shipped it off to Woody's Wheel Works in Colorado to re-drill the spoke angles for a smaller diameter (front GS) hub. This requires moving the spoke hole on the dimple, so to keep the lower edge of the hole and change the angle, you have to drill offset on the original hole and oversize it from the standard .281"o.d. nipple up to .320" o.d. spoke nipple size to re-center the hole and give it a less steep angle. The rims are much thicker than bicycle rims that I am accustomed to lacing, therefore the nipple can't just float around at whatever spoke angle is needed based on the hub diameter and the lacing pattern (most are 2-cross on motorcycle wheels).

This was the best match I could find to the DID WM6 3.50x18 rear flanged drag bike rim I found for $150 laced into a GS1000 hub. Zach at http://www.woodyswheelworks.com is AWESOME, and is doing the work for me and custom making double butted (dual gauge) spokes to save weight (and make up for the larger nipples needed for redrilling a used rim to fit), 8 gauge at the hub and 10 gauge after the bend from the hub all the way to the nipple. I saved $100 having them redrill the rim after paying them $30 plus $50 for the rim plus a few bucks shipping both ways. $20 for a used hub shell.




That's one of my CBR900RR Fireblade rotors in the background, in the harder to find 78mm PCD. Machining some aluminium spacers to locate the rotor centered on the hub and spaced 5mm out to mate to the Tokico twin piston calipers from Kawasaki Ninja's 1998-2010-ish.


Also picked up this late 80's or early 90's GSX1100F (Katana?) front right rotor as a replacement for my heavier stock rear rotor. May upgrade to a GS1150 caliper if the pads are not as tall as the original rear brake's pads.

[Go Mifune]

Good stuff chuck. I like your resourcefulness and ingenuity man.