Topic: '76 CB750K Project #3 - Long and Low - Final thoughts and pics

[Stoli]

Starting to take shape. Invisible front spokes. Trying to cut down on the weight. Ha ha.

[BPellerine]

looks cool but you don't seem to have a lot of travel in the rear susp.bill

[Stoli]

looks cool but you don't seem to have a lot of travel in the rear susp.bill

I guess many of the customs like this are hard tails, but what makes you think that?

[BPellerine]

it may be just the angle but it looks like if the shocks were compressed the tire would hit but I may be wrong.yes most of the low bikes seem to run struts.please don't take offence.bill

[Stoli]

None taken.

I have done a bit of research, so I know the potential pitfalls of changing the rake and trail and wheel base, but this is still rather new to me and I am all ears when someone offers some advice or experience. Just wanted to make sure that I wasn't missing anything. I still need to load up the bike with some more engine weight and a rider to see where my max deflection will be, but I think I'm OK with frame clearance. I just threw on those shocks (they are from a '78K) that I had laying around so might be changing those out for something longer (or shorter).

Making it a hard tail would be easy and make the seat and fender a lot easier to fabricate and mount, but the roads around here kind of suck and I don't think my back would last very long.

[WhyNot2]

good looking so far............................

Is the 650 swing arm a direct bolt on?

Were mods needed to make it fit?

Thanks man.

[Stoli]

Not exactly. The 650 pivot bolt has a slightly larger diameter than the 750 so the holes in the frame need to be drilled out to accommodate. The spacing in the frame where the bolt end of the swingarm goes is very close. There looks to be a tiny amount of side to side play but nothing a small washer wouldn't solve. I haven't drilled out the frame yet. Just using the 750 pivot bolt for the mock up.

The axle on the 650 is a bit longer than the 750. Somewhere between 1/2 and 1 inch, so the rear axle spacers on the 650 are a little wider to compensate. At this point, I am not sure about the sprocket alignment, but I should have that worked out in the next few weeks. I'll be sure to post some details of exactly what I needed to do to make it work.

[MoMo]

Like the invisible spokes ...Larry

[Stoli]

There was a recent thread in the SOHC/4 Bikes section about reducing the weight of your bike by eliminating unnecessary things like spokes and brakes. Some of the posts were so funny I nearly pissed my pants laughing.

Here is one of them:

I am following all of these steps but am not sure how my bike is going to function. Just tried the no handlebar thing and it is pretty tough just holding onto the triple top. So I removed it. Now I am just holding onto the forks (like a hetero man)....and it wobbles before I hit the "ton". My bike is super light, and super fast....everyone wants to be like me, all women orgasm when I look into their eyes. My bike is so light lite fast superfast that I accidentally flew. Like off the ground. The clouds taste funny. On my last ride I bumped into Soichiro. He gave me a high five and told me my bike looked super fast and that I should remove all of the spokes and use a hub less magnet levitation system. So now that's how I'm rolling. Of course I drilled holes in the magnets to keep them light. Working on an electromagnetic system now. Pics soon. Thanks for all the help guys.

By the time I got to "... the clouds taste funny", beer was shooting out of my nose.

[SOHC4 Cafe Racer Fan]

Brakes -- they just slow you down.   

[Stoli]

Decided that it would work better with spokes despite the added weight. Also put some gaiters on.

[Stoli]

The CB650 swing arm fits pretty well. I used the hub from the 750 but needed to use the rear axle and spacers from the 650 to center up the wheel. As previously mentioned, the holes in the frame need to be drilled out to accommodate the larger pivot bolt of the 650 swing arm.  I also added a washer on the sprocket side of the pivot arm between the frame and the end cap to take out the side to side play (see pic below). 

Note: Looks like the chain will need 108 links (530).

[BPellerine]

looks cool .bill

[bjatwood]

looks cool

Totally agree!

[Stoli]

Decided that some cheap mini-gauges are the way to go on this build. Dime City had some bezels that caught my eye so I purchased a couple to jazz up the gauges. They did need some slight modification to fit the DCC 2.5" gauges. Namely, the inner diameter of the rear ring on the bezels need to be increased in order for the ring to slide up the back the gauge body. As is, they are too small and will scratch the sides of the gauge if you force it. A few minutes with some 220 grit sandpaper did the trick. Also, for the speedo with the odo reset stem, I had to cut out 1/2" slice of the rear ring to get past the stem. I cut the 1/2" piece out exactly between two of the screw holes, then after I got it past the stem, I rotated it so it is in the 6-0'clock position of the gauge. Very hard to see, so I am happy. I foresee a lot of brushed metal finish on this bike, so these bezels should be a nice complement.

[SOHC4 Cafe Racer Fan]

Decided that some cheap mini-gauges are the way to go on this build. Dime City had some bezels that caught my eye so I purchased a couple to jazz up the gauges. They did need some slight modification to fit the DCC 2.5" gauges. Namely, the inner diameter of the rear ring on the bezels need to be increased in order for the ring to slide up the around the gauge body. As is, they are too small and will scratch the sides of the gauge if you force it. A few minutes with some 220 grit sandpaper did the trick. Also, for the speedo with the odo reset stem, I had to cut out 1/2" slice of the rear ring to get past the stem. I cut the 1/2" piece out exactly between two of the screw holes, then after I got it past the stem, I rotated it so it is in the 6-0'clock position of the gauge. Very hard to see, so I am happy. I foresee a lot of brushed metal finish on this bike, so these bezels should be a nice complement.

Sexy mod.  Does that mean you will be swapping in a billet tree to match?

[Stoli]

As I mentioned, I have a K6 frame with a K4 engine and a F1 tank. When I raked the front, it brought the top of the triple back at least an inch, so the tank needed to be moved toward the rear to keep the triple from hitting it. I thought my biggest problem was going to be the petcock hitting the #1 carb, but somewhere in the process I noticed that these tanks have a recess on the bottom that allows the #1 and #4 carb stems to move all the way to WOT without hitting the tank. Well, when you move the tank back, that recess is in the wrong place. What to do...

I didn't want to start cutting up the bottom of the tank (don't have the skills for that yet). So I opted to raise the tank just a bit to get the necessary clearance. Hopefully it is enough. I'm not really sure since I haven't reassembled the carbs completely yet. Worst case the carb stem makes contact with the bottom of the tank just before WOT. I don't expect to spend too much time at WOT on this bike so not too concerned at this point.

These pics are a little blurry, but ....

Here is what I mean about the carb clearance. Notice the recess just aft of where the #4 carb stem is. This pic is taken from the right rear of the bike looking forward and up under the tank.



Here is the new front mounting stem position. Moved it back and up a little less than 2":



Did the same with the rear tank bracket. There will be no battery box on this build, so I used the battery box bolt holes for the new bracket mount. No welding required! The original bracket that held the rubber mount was just spot welded on and I was able to pop it off and reuse it without damaging it. You can see the original spot welds in this pic.

[Stoli]

Sexy mod.  Does that mean you will be swapping in a billet tree to match?

Tempting, but I don't think so. Like my other builds, I'm trying to keep this simple and not flashy or expensive. Even though these bezels are sexy, they have a humble brushed metal finish to them that should fit in well with my current vision which is a lot of black with some brushed metal accents.  The tree in the pic is a K6 with the big ugly light panel replaced with some simple handle bar clamps I found on ebay for a few bucks. There really isn't much extra sticking out of it other than the two mounting holes for the gauges, so it suits my needs fine.

Now that the tank is finally mounted, I can start on the seat and rear fender....

[Stoli]

On the other hand, if I found a custom tree with an additional 1" of offset, it would bring my trail back to a more comfortable place. I've searched a bit but haven't found anything yet.

[WhyNot2]

Hey thanks for the info on the swing arm change out.

Looks good man, think i will do the swap myself.

[Stoli]

After a lot of head scratching and procrastination, I finally pulled the trigger on a headlight. In my never ending quest to find decent stuff that doesn't break the bank, I hit a home run on this one. Shame to waste a nice chrome finish (it will be powder coated) but it cost the same as the pos cafe headlight shells that DCC and Carpy sell for $65. And you don't get a lens and bulb with theirs. Billet aluminum and made in the USA as well. Surprisingly nice quality. 



Before someone asks - Yes I am going to get new fork tubes. Just needed something to hold the wheel on for the time being while I scratch my head and procrastinate.

Speaking of head scratching... the seat continues to be a question mark. I keep changing my mind. In the end I might just go with a brat style seat with no rear fender and call it a day. But, I decided to see where this takes me. I can picture a couple of '59 Cadillac tail lights emerging from those holes. Unfortunately I'd need to find some that are 1/3 the size of the actually caddy's .



I was planning on putting the battery under the seat but if I go with the brat seat, I should have enough room under the tank now that I have raised it a bit.

And, the big picture...

[Stoli]

Got some stuff back from powder coat. I like where things are headed. Still not clear on a few things but I'm happy with the wheels.

[bjatwood]

I too like the wheel set up. Am doing a bobber/wing project at the moment and am trying to get my head around a 16" front wheel setup. Tell me about your front rim and who built it..

[Stoli]

The front rim is 19" and the rear is 16". Both are "made" by Drag Specialties and are sold for Harleys. The front rim is actually pretty nice considering the price was only around $95. The rear is adequate but not nearly as nice and cost $72. Bought them both from bikertrends.com. Free shipping. They are actually made by different companies. I think Drag Specialties, like many parts companies, gets parts from different manufacturers and puts their brand on them. The 16" rear is a no-name but the 19" front is made by Excel. I have to wonder if I bought the same Drag Specialties part number again if I would get a rim made by Excel or some other no-name. Anyways, there are some pics and comments on page 1 of this build thread. If you need sizes and part numbers, let me know and I'll dig through my notes. I chose the tires I wanted to put on this bike first, then found the rim widths that matched.

My powder coat guy had told me that he would have to charge me a fortune if I brought him a handful of loose spokes to coat and that it would be much easier for him if the wheel was already laced when he got it. However, I wanted to keep the nipples as polished stainless so that wasn't an option for me (masking them would be tedious as well). In the end, I built a "rack" that he could mount 40 spokes on (3/4" apart) that allowed him to spray an entire set all at once. Easy for him and much less expensive for me.  It worked well and I really like the look.

[Stoli]

Made the seat pan this weekend. Finally. Don't like to work with fiberglass so I'm glad I'm done with that. Still trimming/tweaking the fender and it will need a little bondo touchup but all in all not a bad fit.