1993 CBR900RR - rebuilding an iconic super sport

DreadRock said:
Can't believe I missed this ;D Always like the 900s !

It's such an iconic bike to me, so when this one came my way I knew it was going to be hard to not buy it :)
 
Worst cb650 ever said:
You don't happen to have any of those 900 parts lying around, do you? Like maybe the upper faring bracket...

No, sorry. Actually, the only part I have left is one front brake rotor and I turned it into a clock!

FYI, for an upper fairing bracket, get a newer 95 (I think) on. It is aluminum versus the stock steal part.

Try to use newer parts if they bolt on. As the 900rr progressed, many parts that were upgraded are backwards compatible. The shifter used a linkage versus the stock direct lever. The footpeg heal guards in later versions (929rr & 954rr) are drilled versus stock solid pieces. The later tanks have a softer slope in the rear versus the stock very tall rear. Later axles got bigger (25mm) and were hollow aluminum. Later clutch cables were adjustable (in reach). Later forks are cartridge type. The stock shock is rebuildable with a reservoir.
 
Would the later upper fairing bracket work with the '93 (dual headlight) fairing? I've run into issues where some bits are '93 only, and that's been a bit annoying.

Interestingly, I already have an adjustable clutch cable and drilled heel guards. As I think this bike was drag raced before I purchased it, that's not too surprising. I have forks off a '95, as the stock forks were pretzels, and I read that the '95 forks had revised (better) damping. They are also adjustable. However, they are not USD forks, just plain old USU? forks :D

I think I found a solution to my no speedometer drive issue...more soon.
 
Ok, so I mentioned that the 17" wheel off a CBR600 fits, but does not have provisions for a cable speedometer drive. The fix using OEM parts is to replace the instrument cluster and install the electronic speedometer pickup off a '95 or later 900. That path is expensive, probably between $200 - $400 in parts depending on how lucky I get on Ebay or from the scrapper.

I poked around on Ebay for those cheap $50 Chinese generic instrument clusters, but they don't have water temperature sensors and are missing many of the idiot lights. I did like that they used a Hall effect sensor to pick up speed from the front wheel, however. A bike computer was a good solution, and only $20, but I had this good Honda instrument cluster sitting in front of me already.

I did remember seeing an electronic stepper motor set up to work with the Arduino microcontroller environment, and found it for $20 here: https://www.tindie.com/products/TheRengineer/analog-gauge-stepper-breakout-board/

Interfacing a Hall effect sensor with a microcontroller like the ATMega used in the Arduino system is pretty trivial, as the Hall effect sensor is a transistor triggered by a magnetic field. Think of a switch that closes every time the magnet passes, like a reed switch, only functional to very high RPMs and with built in Schmitt triggering to prevent switch hysteresis.

Here's a neat little example of how to use a Hall effect switch: http://electromechhobby.blogspot.com/2012/12/rpm-counting-with-hall-effect-sensor.html

Note that the input pin to the microcontroller has to be pulled low with a pull down resistor to prevent spurious input from giving bad data to the microcontroller. The Hall effect sensor will pull the input high when triggered.

Soooo, the Hall effect switch will send its output to the Arduino microcontroller, which will send a signal to the stepper motor which will move the gauge needle in the now gutted stock speedometer. Simple, right? ;)

More on this as I get the Hall effect switches in as well as the stepper motor...
 
Worst cb650 ever said:
Would the later upper fairing bracket work with the '93 (dual headlight) fairing? I've run into issues where some bits are '93 only, and that's been a bit annoying.

Yes, it fits. I did it myself. Part number is 64502-MAE-000. It is for the 95-97 bikes.

I use this place for part numbers:
http://www.motosport.com/motorcycle/oem-parts/HONDA/1995/CBR900RR

A good performance mod I did is the Factory Pro Airbox kit. You mod the airbox for airfilter pods (internally) and a jet kit.
http://www.solomotoparts.com/Factory-Pro-Airbox-Plus-Carburetor-Recalibration-Kit-for-CBR900RR-93-99/

I got a lot of 900rr specific info at the fireblades forum.

I like working with Atmel micros too. Are you going to make a speedo from scratch using a stepper motor? I probably wouldn't go thru the trouble but it will be fun watching you do it ;D. I like an analog tach and a digital speedo. Sigma makes good bike speedos. Otherwise, consider Vapor or Acewell gauges.
 
Thanks for the info - I've been doing my best to bend the bracket that came with the bike back into place, but it was pretty messed up in the accident. This opens up my Ebay searching criteria.

Damn, I bet that kit would really bump the power on this thing, especially with the Kerker exhaust on it. It's already stupid fast though! :D

My plan is to install the stepper motor inside the stock speedometer housing and have that control the stock needle. I just realized the odometer and trip meter wouldn't work if I did that. Hmm...
 
Not that it matters if you want to use that rim but unless I'm mistaken, the cbr600 f2 rim has a speedo drive and is visually identical to the f3. Be cheaper than replacing the electrics I'm sure.
 
ABCanuck said:
Not that it matters if you want to use that rim but unless I'm mistaken, the cbr600 f2 rim has a speedo drive and is visually identical to the f3. Be cheaper than replacing the electrics I'm sure.

The issue with the F2 wheel was that the brake rotors and calipers don't fit together quite right, or so the internets tell me. I went with the F3 wheel and said "screw it, I'll figure out the speedo later." I guess it's later now, huh? ;D

So far, I'm $25 into the new speedometer electronics and already have the rest of the bits needed (maybe another $10 worth of parts?). My other idea would be to spin the mechanical speedometer cable with a variable speed electric motor, but that seems (more) half assed. Hmm!
 
Hey, glad your figuring it out. I'll have to double check on the calliper/rotor issue for my swap as I wasn't wanting the speedo drive so I was planning on the f3. Looking forward to see it all together. My plans include the hammer fairing as well so I can't wait to see yours together, painted, and ready for some laps :)
 
I'd make sure you get the spacers from the 600. I'm sure that spacers can be fabricated, but if you can get them and save yourself the work, that is a big win. I ended up accidentally but fortuitously buying a '95 front axle, which is slightly longer than the '93 axle. I say fortuitously because the '95 forks needed the longer axle, which I did not realize at the time. Sometimes stuff just works out ;D

I've been doing some more research on the speedometer issue, and it appears that using a small motor to spin the speedometer input isn't as difficult as I had worried it was. If I can get the speed of the bike from the front wheel using the Hall effect sensor, I just have to spin the speedometer input at 2240 RPM / 60 MPH. I can control the speed of a small DC motor using pulse width modulation through a transistor or small MOSFET. The advantage of this approach is that I retain the stock odometer and trip meter functionality, which is important on a bike with no fuel gauge :)
 
Alrighty, here's the beginning of the work on the wheel speed to motor spinning the speedometer system:

http://www.youtube.com/watch?v=9Lhzw1Cn1r8

In this proof of concept circuit, the Hall effect sensor is pulled high (5 volts) by a resistor. When a magnet comes near the sensor, the sensor flips low, and the microcontroller detects this and fires up the motor. Right now, the motor just runs at about 1/4 of its max speed for testing purposes.

The motor's speed is controlled by pulse width modulation (PWM) through a high current (30 amp max) MOSFET. Basically, the microcontroller switches power to the motor on and off at a high speed, and the speed at which it switches determines the speed of the motor.

The final device will measure the RPMs of the front wheel and convert that into motor speed that matches the speed at which the speedometer cable would normally spin the speedometer. My next step is to pull the instrument cluster off the bike and start doing some tests of what pulse width values correspond with what speeds the cluster shows. At least I should be able to get rid of the annoying Honda overestimation of speeds!
 
Cool! Another Atmel fan. Which micro are you playing with? I use the atmega168 28 pin dip. Yours looks similar in pkg at least. The only issue I see is controlling the inertia of the motor. It will spin a little when the pwm is off. You'll need to incorporate some electrical braking (b+ on both poles). You could command both sides high at off. Tie one side always b+. Switch the other side with MOSFET (N type) pulled low (active low). When it's off, both sides are high. Is the motor at 5 v or 12 v?
 
I've got an atmega328 in my dev system now, but the final product will use an attiny85 because anything else would be overkill and it will keep the size and complexity of the project down.

I'm not too worried about inertia - I want to see how the motor behaves when connected to the speedometer in any case. The motor is a 5 volt unit, but if it doesn't have enough power I'll switch it out for something beefier. The MOSFET on the motor now can handle 60 volts and 30 amps.
 
I just finished soldering up an attiny85 setup with a 7' long lead on the Hall effect sensor, and it worked just fine. I used a 7' cable for a "worst case" scenario. I am not planning on running 84" chopper forks on this :D

The nice thing about setting this system up on something with an alternator and a battery is that I don't have to be stingy with current. I can use a larger / stronger motor as needed to make sure I get the proper spin to the speedometer.

I still have to get back to where the bike is stored and pull the cluster off of it to get the motor fittings set up and test and package the whole thing, but I'm heading out on vacation the end of the week, so the whole project will be on hold for a bit.
 
Bringing this thread back from the dead!

(I'm a poet and don't know it)

I've managed to get the fiberglass nose fairing drilled and installed on the bike now that I'm moved into a house with a garage. There's still some fit issues, but I'm 90% there. I'll get some pictures to update this thread, but even after sitting for a long time, the bike still fired right up after I primed the carbs. Next step will be a test ride up to the gas station...
 
Ok, real pic-tars of the bike and more news...pictures first!

Here's a shot of the front fairing installed - drilling painted fiberglass is a giant PITA, but it fit up ok.
7DcpUc4l.jpg


The bike doesn't look bad from 10 feet away, but stuff starts to get sketchy when you get close...
mhteurrl.jpg


...like the tail fairings, yuck...
YsftUTLl.jpg


...and the heater hose hand grip and zip tied instrument cluster.
Er72niYl.jpg


The good news is that I was able to get enough bits duct taped and zip tied onto the beast that I was able to take it for a ride. I noticed that the rear caliper was sticking, so I took it and the rear master off and disassembled and cleaned them. Unlike my other old junk, neither the caliper nor the master needed new parts, they just needed oooollldddd brake fluid crud cleaned out of them. I noted that the relief hole in the master was completely plugged with crud (this is the small hole under where the reservoir feeds the master, normally next to the larger main fluid feed hole), so I cleaned it out with a micro drill bit. I reassembled it and the caliper with brake assembly grease and they work great now.

I then hopped on the bike and went for a short ride. The bike was really acting odd and I started smelling something burning and saw a little smoke, which I first chalked up to oil/PB Blaster burning off the exhaust. After stalling it a couple times taking off from lights, I finally headed home. As I pulled into my driveway and up to the garage door I realized what I was smelling - hot brake pads! :eek:

I tried to roll the bike into the garage, but now it was like trying to walk a cat on a leash, yikes. I checked the temperature of the rear rotor, which was cool to the touch. However, both front rotors were equally hot, yikes! I had disassembled and cleaned the front calipers, but not the front master, so my suspicions turned to it. I removed the banjo bolt connecting it to the front brake lines, and instantly the from calipers released their death grip on the rotors. Ah ha!

I tore down the front master, which was, unsurprisingly, full of brown brake fluid and crud. Also, as I had suspected, the relief hole in the master was plugged with the same crud that had plugged up the rear master. I cleaned it out with the micro drill bit, and cleaned all the parts off. After inspection, the master was reassembled with brake grease and reinstalled. I bled the master by holding my finger over the outlet and using that to bleed the air out of the master before I attached the lines to the calipers. I bled both calipers again, and confirmed I had brakes that worked and released.

I hopped on the bike for another test ride and could immediately tell that things were better. However, the bike then stalled out at a light and I couldn't restart it. Uh oh, I must be low on fuel and need to turn the petcock to reserve...oh wait, I never turned the petcock on to start with, derp ::)

The ride went great, and I avoided lofting the front wheel, which was no small feat given the torque this monster has. I did lose a Dzus fairing fastener going over some washboard pavement, which was surreal, as the fastener outran the bike and glittered in my headlights as I was bucking over the crappy pavement. Apparently it was a superfluous fastener, as the bike failed to fall apart.

I wasn't happy with the fit and finish of the fairings, however. Many of them are still cracked, broken, or heavily scuffed, but replacement fairing packages are $400ish shipped from China, and OEM fairings are ridiculous money. However, luck was on my side, as I found someone selling a replica set of 1993 fairings in Florida which he bought for his 900, but then ended up parting out his 900 before he installed them. I ended up getting the fairings for about $220 shipped, and they should arrive sometime next week. They are all black, which is the base color of the fairings on the bike now, so I will see if I can find OEM decals to install on the fairings.

I also need a left hand mirror and to do something about the nonexistent turn signals. Replica mirrors are inexpensive on Ebay, and I may end up getting a tail light with the integrated turn signals. I will probably get flush mount signals for the front, as the mirrors with signals built in look like garbage, and the mounts on the bike for the front signals are no longer there. More updates as the project continues - man this is a fun bike to ride!
 
Yea, pretty high class grip I have there, huh? ;D I realized that I can remove the rear housing from the instrument cluster and replace the broken pegs that go into grommets on the fairing stay/cluster mount with bolts, which will replace the zip ties holding the cluster in place. Someone once told me that when buying a used vehicle to deduct $100 from the price for every non-factory zip tie. Seems about right.

The new fairings should ship out today, so I'm excited to get those soon. It's starting to turn pretty cold at night/after work, so I'm going to have work at it to get some rides in before I turn into a meat popsicle (popcycle?). I'll have to redirect some of that air coming off the radiator to warm up my wimpy self, ha ha.

Rich, Mydlyfkryzis, did you notice the 360 lurking in the background? It's parked until PJ finishes with the carbs, so I'm really not neglecting it...
 
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