1980 CB650z RC03 Café Racer (ish) project

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JorgenL
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1980 CB650z RC03 Café Racer (ish) project

Postby JorgenL » Fri Aug 31, 2012 12:05 pm

Okay, here's my little project...

I live in southern Sweden (Helsingborg) and have been into bikes a couple of times but never tinkered with Japanese bikes. I'm mostly a car guy but I like the challenge...

I found a 1980 cb650z rc03. Bought it for next to nothing... carbs all gummed up, non runner.
Got everything fixed to original, passed the inspection.

My mission is a café inspired racer. I want to do as much work as possible by myself, it's a hobby. The bike must be clean and everything that's not really needed has to go. I have no deadline for this build. The bike should be drivable most of the time.

I'll update this first post as the build goes on.

Done
    BCR Café seat and battery tray
    Relocate relay, battery and solenoid to the seat hump
    Excide AGM 4977 battery
    Seat reupholstered, black vinyl with diamonds and gray stitching.
    Replace BCR taillight with Hella Mix'n match LED's
    Lower the headlight with new brackets, getting rid of the bulky stock contraption.
    Small led turn signals & led flasher relay
    New x-ring chain (gold) with safety wired locking clip and new sprockets.
    Marshall 4-1 Exhaust, shortened, gutted and custom made larger diameter baffle.
    Painted and wrapped headers with black Thermo-Tec 2" x 50' and new copper seals.
    Clip-ons
    Venhill diy clutch cable kit, aprox 15 cm shorter than original
    Bar-end mirrors
    OCD cleaned, polished carbs, jetted 120/42, needle clip in the middle one washer shim.
    Velocity Stacks from Steel Dragon Performance with foam filter inserts
    Calipers media blasted and overhauled with new seals.
    Drilled rotors Template
    New stainless brakelines
    SpeedBleeders (SB7100S) from www.speedbleeder.com
    New brake master cylinder reservoir.
    New piston, seals and spring in brake master cylinder (MSB-105 Kit for dual caliper RC03)
    New shifter seal
    Flushed forks and refilled with 15w fork oil
    VFR750 alu footpegs
    Removed the chain guard
    Removed the center stand (but kept the attachment so I can install it in a few seconds)
    Shaved down the side stand to a bare minimum
    Overhaul the ComStars. Paint spokes black, hub silver.
    Relocate horn to under the tank
    Choke mounted under the front of the seat frame to the left (where the side covers attach)
    Replace steering lock (no keys when I bought the bike)
    Shorten/cut front fender
    Hidden crankcase air filter
    New brass swing arm bushings
    Media blasted and painted the lower triple trees
    New top triple tree in billet aluminum
    Ditch the engine guards
    RFY adjustable rear "piggyback" shocks with painted stock springs.
    Aluminium muffler hanger
    Custom oil temp dipstick
    New tapered roller steering bearings
    Drilled shifter
    Drilled tank lock
    Drilled left engine cover
    DynaCoil coils (green) on custom brackets & DynaCoil wires.
    Relocate and put new ignition lock under the seat frame with start on key (like a car)
    Lower the front of the tank about 10mm using offset bushings
    Tank cleaned and sealed
    New adjustable clutch and brake lever
    New low profile throttle
    New mini handlebar switches from Posh (turn signal, horn and emergency stop)
    New professional paintjob on tank, seat, headlight and front fender (Mercedes Palladium Silver)
    Strip down, detab and powdercoat the frame, side stand, swing arm and engine brackets.
    New tires (Dunlop K70) and new Michelin tubes.
    Electrical system total rewire, new connectors, wires and sleeves.
    Relocate (hide) the brake light switch.
    Relocate fuse box to go under the seat.
    New adjustable license plate bracket with led lights.
    Headlight with 2.5" hole for my Acewell speedo from Carpy
    High/Low beam switch on the headlight housing.
    AceWell all in one gauge to replace stock gauges and idiot lights
    All nuts & bolts on the bike are now stainless in the same strength as original or better.

Plans now/in the making
    D R I V E

In the future
    Steering stabilizer
    Carbon fiber/fiber glass slimmed rear fender
    Move the license plate



Here's what it looks like right now...(clickable)

DSC_0066.jpg
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DSC_0070.jpg
DSC_0070.jpg (1.76 MiB) Viewed 6930 times




What it looked like when I got it...
IMG_3637.jpg
IMG_3637.jpg (98.34 KiB) Viewed 32328 times
Last edited by JorgenL on Mon Mar 29, 2021 8:49 am, edited 60 times in total.

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JorgenL
Posts: 141
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby JorgenL » Fri Aug 31, 2012 12:07 pm

A few more...
Attachments
cut-frame.jpg
CUT!!
cut-frame.jpg (64.48 KiB) Viewed 32327 times
battery.jpg
Battery and cables going in
battery.jpg (97.94 KiB) Viewed 32327 times
hump_test.jpg
Testing the seat
hump_test.jpg (66.31 KiB) Viewed 32327 times


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Volker_P
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby Volker_P » Tue Sep 04, 2012 1:28 am

Nice and clean work. :)

JorgenL wrote:Run all wiring in-frame

I would not like to try that with this small diameter frame tubes. Either tricky work with large in-/out holes or small cable cross sections.
Maybe place a parallel, black cover at the inner sides instead. Easier for access in any case


JorgenL wrote:Drill holes in the inner "lip" of the ComStars, only for looks

I am not sure if the inner lip might play a role for the connection of the halves. Better find out before you weaken it. You also drilled the disks yourself, right?

JorgenL wrote:Carb mounted choke lever

As the CB650 typically needs the choke for longer than other bikes, I really like to have it in my view so I don't just forget it after a few miles.


JorgenL wrote:Ditch the engine guards.

They can make the difference between just pick up the bike, kick it all back in place and continue riding or get stucked somewhere with a severe oil leak or smashed ignition. :wink:
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

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JorgenL
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby JorgenL » Tue Sep 04, 2012 1:55 pm

Volker_P wrote:Nice and clean work. :)

Thank you for the input! I've asked myself the same questions.

JorgenL wrote:Run all wiring in-frame

I would not like to try that with this small diameter frame tubes. Either tricky work with large in-/out holes or small cable cross sections.
Maybe place a parallel, black cover at the inner sides instead. Easier for access in any case.
The diameter of the tubes is a problem. The bikes I've done it on before are harleys with bigger tubes. Might just minimize the harness and weld hidden hangers and rails.


JorgenL wrote:Drill holes in the inner "lip" of the ComStars, only for looks

I am not sure if the inner lip might play a role for the connection of the halves. Better find out before you weaken it. You also drilled the disks yourself, right?
I've seen many comstars with holes and some with decorative bolts. But I will see what it looks like when I have them off. Yes I drilled the rotors myself. I know there's a lot of debating if it's good or not. Well it improves braking, especially in the rain. I've done it on a couple of vehicles and I think it's more a "how you do it" than a "if you do it" question.

JorgenL wrote:Carb mounted choke lever

As the CB650 typically needs the choke for longer than other bikes, I really like to have it in my view so I don't just forget it after a few miles.
I'm planing on a microswitch at the lever that will keep the warning light in the acewell speedo lit when choke is on. I forget about the choke even when it's in the stock location so it cant get worse :D

JorgenL wrote:Ditch the engine guards.

They can make the difference between just pick up the bike, kick it all back in place and continue riding or get stucked somewhere with a severe oil leak or smashed ignition. :wink:
Never flipped a bike...yet... this one is the first to have guards. I have been thinking about a simple bar just keeping the covers protected if it falls when on the stand. I've seen something like that behind the plastic on some sportsbikes.

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Volker_P
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby Volker_P » Wed Sep 05, 2012 1:13 am

Covers should not crash when flipped from the stand but a few meters slipping on the street are sufficient.

I agree that drilled brake disks and pod filters improve safety in the wet. Intended or not. :lol:
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

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JorgenL
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby JorgenL » Wed Sep 05, 2012 3:51 am

Volker_P wrote:Covers should not crash when flipped from the stand but a few meters slipping on the street are sufficient.

I agree that drilled brake disks and pod filters improve safety in the wet. Intended or not. :lol:


Haha yea the pods should keep me safe in the wet :D but a few weeks ago I found myself in the middle of a heavy rain (thunder storm) and I thought uh uh.... now I'm screwed because of the pods and everything I've read about them. But to my surprise the bike actually ran ok through the rain... a litte boggy from 1200-2000 rpm at red lights but other than that no problems. The biggest issue was my face because the lack of a front fender (open helmet).
When I got home I let the bike idle in the rain to see what happens when the pods get really soaked and the only thing I noticed was a bit of white smoke from the exhaust... probably just water beeing sucked in.
I guess these bikes are really individual, I have a friend with a 750 (with pods) that runs like crap on a foggy day. In the wet he's not going anywhere.

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Volker_P
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby Volker_P » Wed Sep 05, 2012 4:24 am

JorgenL wrote: But to my surprise the bike actually ran ok through the rain... a litte boggy from 1200-2000 rpm at red lights but other than that no problems. The biggest issue was my face because the lack of a front fender (open helmet).

I have an open helmet, too, so I know the speeds you like to go in rain then. Without glasses, even a bike running on two cylinders would be too fast in rain. :lol:
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

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M_Hills
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby M_Hills » Tue Sep 11, 2012 11:23 am

I am doing a tear down/re-build on my 81 cb650 and want to "cafe" it out a bit on the re-build side of it. I have been seeing those brackets used to move the foot-pegs/rear brake/shifter back on the frame. I have looked around a bit and not been able to find them. Do you have a source that I could look into?

I would greatly appreciate the help!!!
A project bike is very revealing..... like for example..... I've come to realize that every time I project how long something will take, I need to just double it...... I'll then be about 1/2 way there!

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Ruckryder
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby Ruckryder » Tue Sep 11, 2012 12:40 pm

The extended controls are called rear sets , you'll see alot of them on ebay , I have no experience with the quality so buyer beware .
" Don’t be discouraged, because every wrong attempt discarded is another step forward." ~ Unknown

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Volker_P
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby Volker_P » Wed Sep 12, 2012 12:56 am

These alumina plates are the stock footpegs and controls of the European Z-model.
This is the RC03 frame, while 1981 US Standard is RC05.
Not even sure if they would fit a US 1979 (also RC03 frame but slightly different).
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

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JorgenL
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby JorgenL » Wed Sep 12, 2012 3:33 am

Yes these are the euro 650z RC03 originals. I am looking into replacing them because I don't have any passenger pegs and I don't want to grind down the plates. They are very thick and bulky.
I will probably keep the pegs in the same location, just want a more discrete/open setup. So I'll use the plates as templates when I make new ones.

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thegentleman
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby thegentleman » Fri Sep 14, 2012 11:48 pm

how is the project coming along?? clean looking bike to start off with, and definitely looking forward to seeing the modifications made.

hit us up with an update!
1981 CB650C

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JorgenL
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby JorgenL » Wed Sep 19, 2012 4:11 am

Not much progress... I've been dealing with license plate brackets and have painted the seat to protect the fiberglass.

Right now I'm looking into lowering the tank.
If I remove the tank rubber mounts and just hang the tank without them it goes all the way down to the valve covers.
A custom rubber mount with an offset hole might do the trick.
I want the tank to sit only a few millimeters above the valve cover.

I have also run into problems with my clutch, when I put on my clip-ons and rerouted the cable slightly it went from easy/smooth to hard and notchy. When I release the cable from the lever and pull it by hand it's very easy. Guess I have to buy a shorter cable.

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JorgenL
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Re: 1980 CB650z RC03 Café Racer (ish) project

Postby JorgenL » Mon Nov 05, 2012 1:01 pm

Sorting out the wiring part.

New ignition lock in place. On/Off is enough for me. :)
Attachments
20121104_170706.jpg
New ignition lock
20121104_170706.jpg (54.79 KiB) Viewed 31837 times


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