Topic: '78 CB750K cafe-"ish" project - Ottawa

[Buster68]

A couple of weeks ago I picked up a good condition '78 CB750K. A few years ago whenI lived in England I owned a cafe racer '77 CB750F2, and I have been kicking myself for selling it ever since. So I jumped at the chance to pick this one up, and figure I will tinker with it over the winter. Strangely enough, my buddy has a '78 K as well, so we will do some of the work on them together. The bike came in good running order, mostly stock other than the bars and exhaust, and came with a giant rack and back rest that hurt my eyes just to look at it (those came off right away...). Here's the bike, with the horrible rack, next to my buddy's '78.



The bike was in pretty good shape. It needed a cam chain adjustment, a carb clean, and a new set of rear brake shoes, but other than that was great. I plan to do a "semi" cafe racer conversion on it. I want to retain a double seat, because my other bike is a rigid-frame 1953 Harley Panhead chopper with a single seat, so I want to retain at least one bike that I can take my wife or daughters for rides on. So no single-seat cowl or rearsets. But I do like the look and feel of lower bars, so I am going with clip-ons. With that in mind, I will be cleaning up the cockpit with a triple tree from Bullit Custom Cycles in Toronto, a set of mini gauges, and a mounting bracket with mini-LED lights. (BTW, you can see the build thread for my Panhead here: http://www.chopcult.com/forum/showthread.php?t=8406&highlight=panhead)

The Bullit triple tree is a beautiful piece, but still looked a little too modern and "CNC-ish" for me, so I put on on my grinder and rounded out all the edges roughly, and then sanded it progressively with 250, 400, 600, 1500 and 2000-grit sandpaper before putting it on to my buffing wheel for the final polish. Here is the before and after:




The engine is getting K&N pods, and I want to find a smaller reverse megaphone for the exhaust. I have a second seat pan and tank, and I am planning on getting a (slightly) lower, flat tuck-and-roll seat upholstered on the second pan, but which retains the stock hinge and lock (which I find quite handy). If I don't have to cut the stock frame bridge, I won't. For the tank, I am going to try to do a similar cut-out "cafe'd" tank that Vinnie did on his CB:
http://www.dotheton.com/forum/index.php?topic=13529.0

My friend Remi is probably changing his significantly, so I will likely be using the hand-hammered mini fender with some custom LED taillights that our buddy made up for that bike (here it is with the seat up to show how it is mounted):


Other than that, I will be mounting some much smaller solid aluminum turn signals to replace the giant stock pumpkins (I want to keep this bike as legal as possible), and will give the whole bike a thorough clean. I will be pulling the forks, removing the pitted clearcoat and polishing the lowers, and then dissassembing the wheels to powder-coat the rims before trying my hand at relacing (I am going to order fresh stainless spokes and nipples from Buchanan's.) I welcome advice from anyone who has experience rebuilding wheels!

With respect to wheels though, I was disappointed to find that Honda switched to a 17" rear wheel for the '77-'78 K's (I was hoping to go with Dunlop K70's front and rear, but they don't make them for a 17" rim). I suppose if I am rebuilding the wheels anyway, the logical thing would be just to buy an 18" rum and then figure out what size spokes I would need to match them up to the stock hub (I have heard Buchanan's can be very helpful with stuff like that). Is there any reason that wouldn't work? The other option would be just to use an 18" off an earlier Cb750K. Would one fit? (I understand there are differences with the swingarms on the 77/78's, so I am not sure if the axle  or brake/hub  size would be an issue).

While I have the forks apart I will probably take the opportunity to install a set of Progressive springs as well.

So overall, nothing really exotic, but should be a nice little rider by the time I am done. We have about five solid months of snow and cold up here in Ottawa, so I have lots of time to work on it!

[albertaboy]

Hey
Welcome to the forum. I agree there were too many sharp edges to the triple and nice job rounding them off. I like that!!

[Buster68]

So my bike got it's mandatory provincial safety inspection done, with a few odds and ends needing work (new rear brake pads, turn signal relay etc..), but is running great. Or, was running great until i got it home and immediately began cutting things off of it.

I mocked up the front end with the new triple tree and clip-ons. the triple tree only sat halfway down on the fork tubes, so i had to drop the forks about 1/2" to get them on, but I don't think that will be enough to affect the handling at all:



I also have the pods on the bike now, which look better, but I now realize that the side panels are designed to mate with the airbox, and look a little odd without it. I may look at creating a powder-coated aluminum side panel with some speed holes and a mesh behind just to clean up the area and give it some interest:



With the clip-ons, which have a rather bulky CNC bracket, I realized that i will not be able to use the stock brake lever and master cylinder, as it butts up against the bracket, and can't rotate down into a rideable position. So I will have to investigate some options for that - it is a 14mm brake master, correct? I have seen some clean little assemblies online (such as http://slingshot-cycles.com/products-page/master-cylinders/chrome-sport-master-cylinder-for-78-inch-bars/) that would probably be nice on here anyway



I have been spoiled working on my '53 Panhead chopper, which has I think about four wires on the whole bike. I forgot how many cables and wires there were on a bike that actually has front brakes, turn signals, kill switch, etc... I am going to have some serious cabling issues to deal with - shortened clutch and throttle cables, and then rewiring all the new signals and indicator lights:



I wil be running full turn signals on this bike as well - I bought some nice small billet aluminum ones from Dime City. I am going to run the rear ones in the stock position, but cut the stocks down considerably to tuck them in closer to the seat. The front runs I will attach next to the headlight going through each side of the headlight brackets. We switched the rear fender / taillight assembly that my buddy made on to this bike. I think the double LED lights he fabricated look really good, and sort of reflect the look of the two chrome mini-gauges up front. But I am a little concerned that the square bracket across the bottom of the assembly might interfere with the tire when I have a passenger onboard. What do you think?

[Bankerdanny]

Nice work on the triple, the softened edges really improve the look. I love that rear fender/light setup too. I may have to steal that idea for my 550 project as I am not a fan of the no fender look, even with a cowled seat.

I would keep that rack/backrest and just stash it in the garage. I agree it can look ungainly, but when I have passengers, especially kids, I like the idea of the backrest for safety. Plus if you take a trip it gives you something to attach a bag to.

[Buster68]

Nice work on the triple, the softened edges really improve the look. I love that rear fender/light setup too. I may have to steal that idea for my 550 project as I am not a fan of the no fender look, even with a cowled seat.

I would keep that rack/backrest and just stash it in the garage. I agree it can look ungainly, but when I have passengers, especially kids, I like the idea of the backrest for safety. Plus if you take a trip it gives you something to attach a bag to.

Thanks. Yeah, as much as it pains me to look at it, the backrest and the additional rack could be useful if I decide to do a long-distance trip. I had already decided to keep the grab rail, both because I actually like the look of them, and because they are really useful if you need to bungee a bag to the bike, so it is a quick two bolts to attack the rack and seat back.

[apetersonboy]

Sweet! I'm interested in the side panel idea

[Buster68]

So, I am slowly making some progress, although I expect I will make more over the upcoming Christmas break. I dropped my seat off to have it re-upholstered. I had considered buying another ratty seat just for the seatpan, but then I figured my existing seat vinyl was already split, so I might as well use it. What I am doing is getting them to create a "flat" seat rather than the two-level '77-'78 stock seat, with a tuck-and-roll top (similar to the bottom design on my admittedly amateurish sketch below:



I had a lot of trouble getting the seized speedo retention screw out so that I could remove the front wheel - I gather from other entries on the forum that this is not an uncommon problem on CB's. In the end, I heated it up with a torch, gave it a bunch of penetrating oil, and then used a manual impact driver:



As time permits, I have also been cleaning up a lot of the aluminum - removing the clearcoat and sanding with successively finer levels of sandpaper and then polishing, either on my bench wheel, or with a dremel for parts that I am not removing (such as the valve covers). Most of it is coming up quite nice (the pics don't really do the parts justice - most are crappy iPhone pics). I will bring one of my good cameras down when time and space permits. You can the left side versus the right here (it is actually much shinier than this pic indicates, compared to the untouched right side):



Fork legs came up nice as well:

[Buster68]

I cut down the stock rear signal mounts, then dremelled them out to fit the small aluminum turn signals I got from Dime City. I had to cut a bit of the tops of each mount out to fit them around the custom fender assembly, but once I painted them up and mounted them, they almost looked stock (but better - so nice to get rid of those pumpkin-sized monstrosities.) The plan for the forward ones is to drill an additional hole in each headlight mount and put them on either side of the headlight, out of the way.

[Buster68]

I ran into a problem when I initially mounted my clip-ons - the stock brake level and master cyclinder assembly ran into the the bulky clip-on mounts, preventing the lever to be tilted down enough. I ordered a smaller 14mm Nissin brake master cylinder and lever:



It fit great, and looks pretty good on the bike too (I removed both the brake lever and the clutch lever (after having peeled off the 30-year-old yellowed plastic coating) and polished both on my bench wheel.



Finally, I got my exhaust in from Dime City, which was a bit of a disappointment, only because I could have sworn I ordered the 12" shorty, but I got the 18" standard reverse megaphone. I checked my order, and it says the long one, but I certainly meant to order the short one (delivery fees and duty here in Canada make it impractical to send it back to exchange it). The quality of the pipe is great, and the look is growing on me, even if it isn't the one I wanted. I still need to get a small tab welded to it for the mount.



As an aside, I should note that between the bone-chilling cold (it was -20C / -4F here the other night) plus how crowded my tiny 1930's garage is, it is challenging working on the bike:

[snowman]

I hear you about the temperature, it's been the same here in Montreal. I like what you did with the rear signal mounts and will have to steal your idea for mine.

Also I noticed that you installed some bushings and was hoping that you can tell me where you picked them up.

By the way I contacted the vendor about the plate with the warning lights and unfortunately they stopped production. So I went with the mini gauges from DCC with built in idiot lights.

What you've done so far has inspired me and now it's time for me to start polishing, any tips would be appreciated.

Cheers


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[Buster68]

I hear you about the temperature, it's been the same here in Montreal. I like what you did with the rear signal mounts and will have to steal your idea for mine.

Also I noticed that you installed some bushings and was hoping that you can tell me where you picked them up.

By the way I contacted the vendor about the plate with the warning lights and unfortunately they stopped production. So I went with the mini gauges from DCC with built in idiot lights.

What you've done so far has inspired me and now it's time for me to start polishing, any tips would be appreciated.

It's -23C here today (that is -9 degrees fahrenheit for you Americans)

That's too bad about the plate with the indicator and warning lights, but it might be a mixed blessing that they don't offer it anymore - I am having a lot of trouble figuring out how to wire it up, and I am not convinced that the mini-LED's are going to be robust enough to work on the bike. They seem apt to fall out the bottom of the plate and the leads are very fine and look prone to snapping - I think they only way to get them to work would be to encase the bottom in non-conductive adhesive, but then it would be next to impossible to change the bulbs if they go out. It almost makes me want to figure out a way to attach the stock indicator / ignition panel to the new triple tree.

Anyone who has experience wiring mini-LEDs and who has tips to pass on would be appreciated!

As far as polishing, I tried using a dremel with a flap wheel on one side, but found that put some pretty deep gouges in that were hard to polish out. So since then I have just been starting with about a 230-grit sandpaper wrapped around a rubber sanding block to get the old clearcoat off and do a rough smoothing, then using successively finer papers (400, 600, 1000) before putting it on the buffing wheel on the bench grinder, or using the dremel with cotton buffing wheels and some polishing compound (white or green).

[snowman]

Here's something that I found on another post that I am going to help wire my indicators and it might help you.




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[Buster68]

Here's something that I found on another post that I am going to help wire my indicators and it might help you.

Thanks! That is really helpful

[Kemp]

Yes, Ripple Rock Racers is no longer represented by Bullit. RRR which makes the Billet Top Triples, Complete Billet Triple Assemblies and Aluminum Instrument Consoles etc; will soon have it's own web site. These parts are made in Brampton Ontario. The LED consoles for the Billet Top Triples are designed to hold the 2:25 "Mini Gauge Instruments commonly available and can also have the LEDs separate as you have chosen. The LEDs have 2-20 gauge wires, the red wire is positive and the black wire is negative. 20 gauge wire is common for LEDs as the current draw is only 20 milliamps and it is robust. It will not break or come apart of crimped correctly. The trick is to always use a crimping tool designed for motorcycle connectors. You will never get a solid crimp with just a std electrical crimper. If you want a proper OEM crimp, use the proper tool! With LED wire I usually strip it a bit longer and fold it over a couple of times as the gauge of wire is smaller than the original on the bike, this helps with crimping as you will be using OEM bullet connectors which is a bit larger gauge. OEM metric wire terminals are available at most motorcycle dealers or can be ordered through m/c parts distributors like MC Distributing in Canada. Use the standard bullet connectors (both male and female) as connectors and connect them to the exact same wires that the original indicator lights were connected to. RT turn is light blue, Lt turn is orange, Neutral is LT Green/Red, Blue is high beam, Oil is Blue/Red (I think on your 750). The black wire from each of the LEDs should go to the Green (ground) wires and you can combine them together if you like into one terminal connector. It's actually pretty simple once you've done it! LED's won't light up if you mix up the positive and negative wire so that's important to remember. The LEDs are all prewired with resistors on board so they are ready for the motorcycles 12 volt system. Since you are using separate LEDS for both RT and LT turn signal indicators you will have no issues with one way diode that is necessary if only one LED is used for both rt and lt signal functions. To prevent the rubber stoppers from coming out of the LED holder just put a dap of silicon seal. This will give added security and still allow you to change the LED when necessary. The new console you have has rubber grommets on both it's mounting holes to help extend the life of the LEDs and the Mini Gauges. It should be good!

[Buster68]

Yes, Ripple Rock Racers is no longer represented by Bullit. RRR which makes the Billet Top Triples, Complete Billet Triple Assemblies and Aluminum Instrument Consoles etc; will soon have it's own web site. These parts are made in Brampton Ontario. The LED consoles for the Billet Top Triples are designed to hold the 2:25 "Mini Gauge Instruments commonly available and can also have the LEDs separate as you have chosen. The LEDs have 2-20 gauge wires, the red wire is positive and the black wire is negative. 20 gauge wire is common for LEDs as the current draw is only 20 milliamps and it is robust. It will not break or come apart of crimped correctly. The trick is to always use a crimping tool designed for motorcycle connectors. You will never get a solid crimp with just a std electrical crimper. If you want a proper OEM crimp, use the proper tool! With LED wire I usually strip it a bit longer and fold it over a couple of times as the gauge of wire is smaller than the original on the bike, this helps with crimping as you will be using OEM bullet connectors which is a bit larger gauge. OEM metric wire terminals are available at most motorcycle dealers or can be ordered through m/c parts distributors like MC Distributing in Canada. Use the standard bullet connectors (both male and female) as connectors and connect them to the exact same wires that the original indicator lights were connected to. RT turn is light blue, Lt turn is orange, Neutral is LT Green/Red, Blue is high beam, Oil is Blue/Red (I think on your 750). The black wire from each of the LEDs should go to the Green (ground) wires and you can combine them together if you like into one terminal connector. It's actually pretty simple once you've done it! LED's won't light up if you mix up the positive and negative wire so that's important to remember. The LEDs are all prewired with resistors on board so they are ready for the motorcycles 12 volt system. Since you are using separate LEDS for both RT and LT turn signal indicators you will have no issues with one way diode that is necessary if only one LED is used for both rt and lt signal functions. To prevent the rubber stoppers from coming out of the LED holder just put a dap of silicon seal. This will give added security and still allow you to change the LED when necessary. The new console you have has rubber grommets on both it's mounting holes to help extend the life of the LEDs and the Mini Gauges. It should be good!

Kemp - thanks for the detailed info! I love the look of the gauge panel, but I was getting a little worried about wiring it up.

Are you guys going to have any kind of a storefront operation for Ripple Rock?

[Kemp]

Hi Buster68, my partner is moving the machine shop to Guelph and may have a bit of a store front there as the space is much bigger. Will still continue in Toronto to build bikes and design fun new stuff for the SOHC4. Maybe see you at the bike show in January at the International Center!

[Buster68]

The trick is to always use a crimping tool designed for motorcycle connectors. You will never get a solid crimp with just a std electrical crimper. If you want a proper OEM crimp, use the proper tool! With LED wire I usually strip it a bit longer and fold it over a couple of times as the gauge of wire is smaller than the original on the bike, this helps with crimping as you will be using OEM bullet connectors which is a bit larger gauge. OEM metric wire terminals are available at most motorcycle dealers or can be ordered through m/c parts distributors like MC Distributing in Canada. Use the standard bullet connectors (both male and female) as connectors and connect them to the exact same wires that the original indicator lights were connected to.

I couldn't find a website for MC Distributing, but are these what you are talking about?

[Kemp]

Yes, those should do the job! MC Dist wouldn't sell to the public as they're distributors but most bike shops in Canada will have their catalog and handle their products, sort of another Parts Canada. If you're having trouble getting connectors just PM me and I'll send you some. Like what you did with the top triple, very nice custom touch. The 1/2 inch drop won't affect the handling other than the front end may feel a little better, a slightly sharper turn in on corners should result but you might not feel it. If you were roadracing the bike, you'd want to do that as it helps to put a bit more weight on the front and sharpen up the steering to where you'd feel more comfortable with the initial turn in to the corner and a better transient response as you go from full lean one direction to full lean in the other. Lots of fun these bikes!

[snowman]

What bummer, I just went a purchased a new mini speedo with the integrated idiot lights because I wasn't able to get the mounting bracket with the lights.

Oh well, maybe with the new store and hopefully website there will other items for my build. Still freezing here in Montreal.........


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[onetruepunk87]

Nice start, keep up the good work. I love what you did with that top triple, it looks great polished up with the rounded edges. Also, how you mounted up your rear turn signals is exactly what I did on my '77.

[snowman]

The trick is to always use a crimping tool designed for motorcycle connectors. You will never get a solid crimp with just a std electrical crimper. If you want a proper OEM crimp, use the proper tool! With LED wire I usually strip it a bit longer and fold it over a couple of times as the gauge of wire is smaller than the original on the bike, this helps with crimping as you will be using OEM bullet connectors which is a bit larger gauge. OEM metric wire terminals are available at most motorcycle dealers or can be ordered through m/c parts distributors like MC Distributing in Canada. Use the standard bullet connectors (both male and female) as connectors and connect them to the exact same wires that the original indicator lights were connected to.

Hey Buster, where did you pick up the crimping tool? I had a look at Cdn Tire and no luck. The other option is to do what Kemp suggested, go to the local bike shop and have them order from MC, just afrais that equals big bucks.

PS. weather finally broke, so will make the work in the garage easier, since I normally keep the heat at a minimum, cause the wife and kids use it as thier main entrance to the house.

I couldn't find a website for MC Distributing, but are these what you are talking about?

[Buster68]

I ordered a set of the crimpers, plus a bunch of billet connectors, a set of new rubber side panel grommets, and a fuse box for my CB, from CB750parts here in Ontario. When I get home I will find the link

[Buster68]

Snowman - sorry, it was VintageCb750.com - they have a great selection of CB parts, and you don't get stuck with the brutal shipping costs coming from the States to Canada. Here is the link:

http://www.vintagecb750.com/products/5/electrical/64/wire-terminals-couplers-fuse-boxes-fuses

[snowman]

Thanks Buster, have yourself a Merry Christmas.


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[Buster68]

Snowman - sorry, it was VintageCb750.com - they have a great selection of CB parts, and you don't get stuck with the brutal shipping costs coming from the States to Canada. Here is the link:

http://www.vintagecb750.com/products/5/electrical/64/wire-terminals-couplers-fuse-boxes-fuses

Hmmm ... +1 to VintageCB750.com for promptness - my package arrived today, only two days after I placed it. However -1 to them for not including the crimpers I paid for in the box with all the bullet connectors and covers (which are useless to me without the crimper that I paid for). And I am guessing the chances of getting it before Christmas so I can work on the bike will be slim...

* UPDATE: vintagecb750.com just got a hold of me and said they would send out my crimpers. I guess I won't have them to work with this weekend though, as i hoped