The GS Cafe

[G-3]

G-3, Though I see you have a kick start{lucky dog- my '80 doesn't}, how'd you loose the battery...or did you? I love the clean thru look with it being gone from the oem location. I miss my H-2s, Rd, CBs and KZ-B that had kick.{no choice on the H-2s and RD-lol}
Nice ride!

Thanks bro, battery still there it's a tiny lithium led type 1.25lb it's got all the power i need and can go a year without a charge. I got it off amazon for 100$

[80GS850GBob]

Thanks bro, battery still there it's a tiny lithium led type 1.25lb it's got all the power i need and can go a year without a charge. I got it off amazon for 100$

Cool, my buddy is building a CB750 cafe and was wondering how to pull that off....I will convey the idea to him...now all he has to do is loose the huge oil reservoir that bike has.
Thanks!

[Chuck78]

GS1000 makes a poor cafe racer..... Maybe less cafe, and more Superbike.



...or for inspiration, this:

The term cafe racer is pretty relative since the advent of japanese inline fours, as it's taken on an expanded meaning and medium. I've seen many fantastic "cafe racer" or other racer type builds out of our beloved vintage Japanese bikes, many of which have been on this forum. Unfortunately the expanded meaning of the cafe racer designation often includes things like cheap chinese shocks, mostly all cosmetic "alterations" including chopping the frame and learning to mig weld for the first time, making low quality zip tied on fiberglass seats that are too uncomfortable to race on even, installing GSXR/etc forks that are far too short, installing massively oversized rear brake rotors that are totally unnecessary even on a race bike...

Anyhow I'm somewhat numbed to the term, but heck, a well built/modded GS1000 with it's stiff frame that is far superior to old british and japanese frames can handle pretty darn well in tight corners, enough to call it a cafe racer I suppose. a lightweight twin could win a "cafe race" running like mad through tight city streets, making tons of 90 degree turns at tight intersections, whizzing in and out of cars, but in real world terms on a safer road like some tight twisties, a well built GS1000 would smoke any british twin cafe racer...

[Chuck78]

Is that your GS1000 at the top? Those Fox Factory Shox are worth their weight in gold, well worth putting hundreds into restoring, mine ride incredibly (see below). My bike is built up with those in form similar to a vintage superbike but even with longer swinger handles incredibly well in tight turns thanks to updated geometry and awesome tires (Shinko 230/741, Pirelli, or RoadRiders usually).

GS1100E alloy swing arm, Fox Shox, Cartridge Emulators, Tarozzi fork brace, GS1150 rear caliper, 275mm (smaller than stock GS750) rear floating rotor off of a front GSX1100 Katana 1989-1991, CBR900RR rotors and Ninja 600 calipers modded to look like a factory bolt on, 3.50 and 2.75 Sun alloy 18" rims and s.s. Buchanan's Spokes, drilled Vortex countershaft sprocket, SuperSprox alloy rear sprocket with steel ring gear, 530 Hayabusa grade chain, minor head work and Serdi radiused seat valve job, MTC 920cc pistons, GS1000 carbs, K&N RC2222 dual oval plenum open filters, smaller/lighter GS400 gauges, drag bars, smaller GS1000L headlight, Tommaselli style headlight brackets, CB400 style turn signals,tiny 4 cell LiFEPO4 battery, starter delete, starter clutch and flywheel delete (kicker only), Dyna-S ignition, etc... Still a work in progress. Different head and MegaCycle or Web cams and springs next year. Usually only mu bud on a late model Ninja can keep up in the twisties, all the other vintage bikes and early Ninja, ZRX1100, etc... behind me, occasionally in the ditch, which led me to give bigger disclaimers on the "ride your own ride" and "don't try to keep up with me, I'll be waiting for you at stops and changes of direction." Not fun to have your friends on archaic handling vintage stockers or even newer sport bikes end up low siding or running off the road.





Unfortunate typical crappy "Cafe Racer" KZ550 behind mine. Too many builds like this are running around, and make me appreciate much more a very well crafted, well thought out, functionality-purpose built cafe or other racer styled bike. Modded with a terribly uncomfortable seat held on by zip ties and resting on a 2x4 screwed to the frame up front. built up by unbuilding it, deleting speedo tach functional turn signals fenders stock seat etc, add aftermarket headlight, clubmans, and a terribly seat. Call it a good runner because you can putz around under 1/4 throttle on it, but any big throttle twisting makes it cough and spit and sputter, because it needs a dynojet kit or adjustable needles and custom drilled (enlarged) jets for the unsupported TK22 carbs... Lucky for my friend, it came with Ikon/Koni 7610 shocks, and a Kerker 4:1, and he was able to get the missing parts minus the stock seat back with the transaction. Oh yeah, EMGO pods, airbox gone with the seat. Bonus, extra electrical tape X'd on the headlight for if you need any when you break down from not going through the entire wiring harness because you spent too much time doing silly cosmetic mods...

We're going to be making something much nicer out of 'er soon. Rebuilt and jetted carbs, reshaped and recovered KZ550LTD seat, fork upgrade, maybe dual disc upgrade, gauges reinstalled, etc... GPz550 head and cams and a Wiseco (615cc?) piston kit are things I am trying to convince him to spring for.

[Chuck78]

What I really want to build now more in cafe form minus the cafe seat treatment is this:
1979 Suzuki GS425
GS1100E, GS750, GS500, or Bandit 400 swingarm (bike is a wheellie machine mostly stock, needs more length)
custom JE 11:1 475cc pistons
modded/narrowed GS500 carbs
Japanese aftermarket KSY or MadMax upswept racing 2:1 exhaust
Lunchbox type air filter for GS500
Koni 76F alloy body vintage twin tube shocks rebuilt
GS500E fork in GS1100E alloy triples with AllBalls bearing conversion
RaceTech Gold Valves and chopped springs or aftermarket
custom CNC'd fork brace
DID alloy 3.50 and 2.50 18" rims on GS750/1000 spoke wheel hubs
Pirelli Sport Demon 130/70-18 rear and 110/80-18 front
520 chain
offset front sprocket
supersprox custom rear sprocket
37mm clip on bars
stock flat GS400 seat or recovered and shaved GS425 seat
stock GS tail section
kickstart only, manual cam chain tensioner to combat the high compression kickbacks on the kicker (found out the hard way on the 920cc 750, jumped time twice on failed kickstarts - have to stand on the bike to prevent the kickback)
Lithium Iron Phosphate 4 cell battery
Dyna S, Dyna 2000, C5, or custom GM HEI ignition module
center stand delete
possible turn signal delete if I can't find very small very bright running light turn signals
Tomaselli headlight brackets
LED or HID headlight conversion

Now that will be more in the form of a true cafe racer or true lightweight sport oriented vintage twin rather, but with a shaved down stock seat maybe looking like the Brat style but with a GS tail section. could go solo seat on this purpose built Appalachian hills corner burner, but space for a random passenger or saddlebags is always a plus

Larry "TheIronLung1976" is building a similar 449cc GS400. On hold temporarily, but lookout for him back on here this fall/winter.

[Chuck78]

What else I really want to build is this:



Rickman CR frame kit (mid 70's through early 80's, built for CB750/Z1/GS1000/etc)
big bore GS750 engine (894cc or maybe resleeved 850's with GS1100G sleeves and 1023cc?) or GS1150 engine
Honda VTR1000C SuperHawk forks, RaceTech springs
Fox Factory Shox or new YSS Piggyback's
Rickman repro aluminum stretched gas tank
Rickman dual seat? Maybe custom seat and GS tail section
3.50/2.50 DID alloy rims 18" on GS hubs
Pirelli Sport Demons 140/70-18 and 110/80-18
GS400 gauges or Dime City stainless steel mini gauges
clip ons
Rickman rearsets
Grimeca rear brake
CBR900RR 296mm front rotors, Honda SuperHawk or RC51 race calipers and pads
Marving flat collector upswept racer 4:1 exhaust

Now that will be the ultimate ultimate vintage racer styled bike, with the help of the big cc Zuk four and the incredible and rare Rickman frame. Trying to procure the frame this month. Long term project. 673cc GS550 engine build for the wife, maintenanace on her bike, head and cam work on my bike, house rehab...those all come first.



Below are two Rickman CR750 (CB750 engine and wiring, side covers, gauges) rolling chassis kits. CR is typically credited as being "Competition Replica," but even magazines from the 1970's reviewing them called them CR for Cafe Racer. CR900 was a Z1, CR1000 was a KZ1000, GS1000 or rare Predator GS1000 (also CB900F based Rickman Predators). The Rickman was a frame upgrade made from Reynolds 531 fillet brazed lightweight high strength tubing and nickel plated, with Lockheed and Grimeca brakes, Boranni rims or various racing mags, upgraded fork, etc.

[Chuck78]

Hey,
GS 550E (modified a little bit ). It lives in Germany (like me too).

Greets
Sven

Great build, Sven! Wiseco used to make 740cc pistons for the GS650's. you can modify your GS550 crankcase to fit the 673cc 9.4:1 GS650 top end also, and maybe have some custom pistons made to be 740cc I think it was, 3mm oversized. GS650 had 73hp stock, and with rejetting, K&N's, and aftermarket exhaust, you could push near 80hp at the crankshaft. That would be one awesome bike!

The GS1000 with Fox Factory Shox I just noticed has Morris Mag wheels same as many Rickman's

[sven77]

Great build, Sven! Wiseco used to make 716cc pistons for the GS650's. you can modify your GS550 crankcase to fit the 673cc 9.4:1 GS650 top end also, and maybe have some custom pistons made to be 716cc I think it was, 3mm oversized. GS650 had 73hp stock, and with rejetting, K&N's, and aftermarket exhaust, you could push near 80hp at the crankshaft. That would be one awesome bike!

Thank you.
That is exactly what I thought.
Combined with a modified Duc 748 dry clutch this will be nice.

Greetz

Update:
Step 1 finished, got my 650 cylinders today (head will follow soon)
Step 2 will be to ask about different options to make 750s pistons fit
to be continued...

[rudeman]

@CG "G-3 I assume your bike is a 750 and I really can't remember for sure. Look up a fellow named Spiff, from Norway who did some mods similar to yours, but he has a 850 top end on it. I'm not that adventurous, just mentioning it."

Yes it's a 750, if i get crazy enough this winter i'll contemplate doing some thing like that! But i was thinking about putting it up to the GSR for a vote, 850 stroke kit or dropping in an engine from a 78-79 gs1000 if i can find one?

The 850 top end and pistons are virtually a drop-in on the 8V 750.

[Weasel]

Great thread and cool bikes. Sven, I REALLY like the style of your bike. I just picked up a '78 GS750 yesterday and I plan to build some sort of cafe racer. Sounds like there are a few critics here but I guess that's no different than any other forum. Build whatever bike you like, as long as you enjoy it. I'm not a professional builder so I'll be building my bike to the best of my ability in the cafe style that I like. Will it be a true cafe racer? Whatever that means...who cares, I know I don't. I do know that my daughters and I will have fun and they will learn and know some things most men these days don't.

Cafes are over done like choppers? I guess my part of the country was immune from that. Or maybe I was out of the game too long. We had choppers everywhere but I can't honestly remember the last time I saw a cafe racer around here. But again, who cares. I think baggers are horrendous examples of a motorcycle but that is my opinion. But some people love them so more power to them. I'm building a cafe racer style bike because I love the look of them, not because it is or was trendy or cool.

[sven77]

Sven, I REALLY like the style of your bike.

Thank you.

I just picked up a '78 GS750 yesterday and I plan to build some sort of cafe racer.

Nice choice.

Sounds like there are a few critics here but I guess that's no different than any other forum. Build whatever bike you like, as long as you enjoy it.

Build an ,,everbody's darling"-bike would be such a boring thing. Critics are only people with a different understanding of what a bike has to look like. And for me this is absolutely ok. If everbody would have the same style in bike-build... Oh, do not even think about it...

I'm not a professional builder ...

Nor me.

I do know that my daughters and I will have fun and they will learn and know some things most men these days don't.

I'm building a cafe racer style bike because I love the look of them, not because it is or was trendy or cool.

I started to build my ride 6years ago. In 2009 people thought my ride would use coffee instead of fuel if I told them about cafe racers.

[80GS850GBob]

Anyone ever try mounting an HD solo seat to a Suzi GS? Looks like it might work with a few mods...and some kind of tail piece.

[Chuck78]

Step 2 will be to ask about different options to make 750s pistons fit
to be continued...

This has been tried before, and it has never worked out well. Way too high of compression even after serious reshaping of a hemi domed piston to fit a kidney-shaped close chambered head, runs far too hot from the high compression and thin cylinder walls, not a streetable combination. Best bet is to have JE Pistons, Wiseco Pistons, or Carrillo's CP Pistons custom make some forged pistons based on the original 650 cast slugs. Then you get deeper valve reliefs to run higher lift megacycle cams that will really boost performance...

[Chuck78]

Also another method has been to reshape the head to fit the hemi piston, but that basically reverts an advanced modern high efficiency head design back to the stone age.

The best bet is stock 650 pistons on a slightly milled head and block, polished exhaust ports and lightly cleaned up intake ports, stock springs, back cut valves on a fresh valve job, and the base model hot street Megacycle cams that work well with stock pistons and springs. Then make the gs550 cam sprockets slotted, and degree the cams in to the desired performance range. 104-106 works best for the early 2 valve gs cams I have read. I know that with mine advanced a good but, my gs750 made monstrous mid range torque that I'd never felt before, but around 110 lobe centers, it would wake up like a rocketship at 6500-11000rpm. Everyone within 3 miles knew when I would get into it though! That's what's nice about a street engine with the cams timed fir more midrange, still very very powerful and fun but not necessary to rev it to the moon

[80GS850GBob]

"Rear sets for early GS cycles".......are there any?.......adjustable would be better.