Topic: 1976 CB750F - first bike, first build - mild cafe

[riffman12]

I have an example of each and can do a mock fit up for both and will let you know. Might not be until the weekend though! 

That would be awesome. Thanks man! 

[Jerry Rxman Griffin aka MuthaF'er]

Consider those 'rear calipers' and not brackets ;-) You tryin to confuse us old guys LOL

[riffman12]

Haha well the 76 unit is a caliper, but the 77/78 is just a bracket that holds the caliper. 

[riffman12]

OK quick update as it's been a while. I've been really busy with wiring, controls, cables etc. as well as waiting for my new rear end parts to arrive. Here's the quick take:

1) It looks like the combination of 77/78F Comstar + earlier sprocket carrier is working PERFECTLY. The chain line between the two sprockets is really straight. Thank you all for helped with that. It even looks like I can use the 77/78F brake caliper holder to avoid using the overpowered '76F rear brake.

2) I finished all my wiring (except for turn signals and tail light as I haven't ordered those yet). Turned the key and all the warning lights, horn, and headlight are functioning properly. Hooray!

3) mounted my freshly re-jetted carbs and airbox with re-oiled K&N filter

4) Last thing before firing the bike was to get the Carpy 4 into 1 exhaust mounted. Perhaps you saw my thread in the Bikes section, but the flanges on the system were not the right size for my 750. See pics:






Here's my factory flanges on top of the new Carpy ones. You can see how the holes are way too close together. They don't fit the studs




I'm talking with Carpy at the moment on how to deal with this. Sounds like he'll replace it.

[riffman12]

update on the exhaust issue: I sent the exhaust back to Carpy and after inspection he admitted fault. He built a new one with new correct-sized flanges, had it coated in less than a week and sent it back to me. He covered shipping, and as I needed turn signals he threw in $60 worth of turn signals to cover the $40 I paid to send the exhaust back to him. Overall a bit of a hang up in the build, but he handled it very professionally and quickly.

I started the bike with the new exhaust and it runs great.


Quick question:

The piece of the wiring harness that comes up into the headlight, do I route that over or under the bottom of my triple clamp? At the moment I have it under and it just looks awkward.

I'll put up more pics soon

[przjohn]

It goes under and has a clamp that holds it up to the lower clamp.

[riffman12]

A quick update as it's been a while since I posted pics.

I chopped more off the back of the frame as I was having seat mounting issues. Waiting on a new hoop to weld in.




Got the front brake calipers rebuilt and mounted. Now I'm just having issues with brake lines.






These are the two brake splitters I have. I'm not sure which one to use. Also, where do I mount these things?




The only place I can see if a hole in the front of the lower triple clamp (where the bolt is):



But then the splitter won't be centered. Any ideas?



And finally, here's a pic of how the bike sits now with the seat and tank mocked up. Just some finishing touches and hoping to have this thing on the road by April!

[calj737]

The splitter goes in the hole you identified. The lower unit in your hand is the stock type, I don't recognize the other.

[riffman12]

the smaller one is the stock unit? I found this picture of someone's '77F build and it seems he is running the bigger one:




I have dual front disks so I think using that offset hole will align things funky with the 2 calipers. Any ideas on how to mount this it centered?

[Retro Rocket]

^^ thats not a 77F^^   

[riffman12]

ah my mistake. The front end looks like it's from one?

you can see the splitter in this picture:



How does it mount?

[SOHC4 Cafe Racer Fan]

I don't have an F1 or F2, but it looks like it bolts to the bottom of the bottom triple tree.

[madmtnmotors]

These are the two brake splitters I have. I'm not sure which one to use. Also, where do I mount these things?

So, you are using a 77/78 front end on a 76 F model, is that correct? The proper brake line splitter is the upper one (closer to your finger tips) in the photo above for the 77/78 F model. The lower triple has two mounting holes to mount this splitter to the front of the lower triple. Did you use the triple trees from a 77/78 F model? The 76 F model lower triple will likely not have these two holes, probably only one. Now you have to decide whether to "make it work" or "make it right". Either way is appropriate, as long as careful consideration is given when deciding to "make it work".


Edit: Look at the parts fiche for part number 53200-410-000ZA

Edit: Compare it to the parts fiche for part number 53200-392-000ZA

[SOHC4 Cafe Racer Fan]

Since this is not a restoration, you have many options. You don't even need to use either stock splitter. But, I do understand Wilbur's sentiment.  I think the most efficient solution is to tap the bottom of your triple tree or use a F1/F2 bottom tree if you got one with the parts.

[madmtnmotors]

Since this is not a restoration, you have many options. You don't even need to use either stock splitter. But, I do understand Wilbur's sentiment.  I think the most efficient solution is to tap the bottom of your triple tree or use a F1/F2 bottom tree if you got one with the parts.

I'm not sure the early lower tree would accommodate "tapping" a new hole, especially if you compare the fiches for the part numbers above. I would think a simple bracket, using the single mounting bolt, would enable you to provide a mounting point for the two holes in the later splitter. The "splitter" on the bottom is the early type that used the splitter to provide a mounting point for the brake light switch, isn't it? I guess either splitter would work, a splitter is a splitter is a splitter...

[riffman12]

thanks a lot guys. After checking those fiches, I realize now that the previous owner adapted the '76F front end to either have entire fork tubes from a '77F, or just the fork lowers. The triples are from a '76F as there is only one hole, offset to the left.

Either way, sounds like my best course of action is to make a little bracket using that offset hole to center my splitter in the middle of the clamp.

On the smaller of the 2 splitters that I have, there are some little bumps around each hole to "guide" the banjo end. Am I ok grinding those off to give myself more options for mounting? Or are those important? These are the things I mean:

[madmtnmotors]

thanks a lot guys. After checking those fiches, I realize now that the previous owner adapted the '76F front end to either have entire fork tubes from a '77F, or just the fork lowers. The triples are from a '76F as there is only one hole, offset to the left.

Either way, sounds like my best course of action is to make a little bracket using that offset hole to center my splitter in the middle of the clamp.

On the smaller of the 2 splitters that I have, there are some little bumps around each hole to "guide" the banjo end. Am I ok grinding those off to give myself more options for mounting? Or are those important? These are the things I mean:

Will they work as is?

Welcome to the world of "Customization"! 

[Jerry Rxman Griffin aka MuthaF'er]

Those tits hold the line in place. Helps when tightening. Can it twist loose in action?!

[riffman12]

hm OK I'll try and keep them. They just force the line into an awkward position.

I think I'll use my bigger splitter. That one lines up properly. Now to make a little bracket...

Also aiming to weld the rear hoop in this weekend. Will post pics.

[Roach Carver]

nice build. following along.

[riffman12]

had a friend weld my rear hoop on this weekend. It fits the seat perfect. Very happy with the results

[SOHC4 Cafe Racer Fan]

Nice robust hoop/cross-member!  I am doing something similar (kicked up hoop) on my 550/650 project.

[slikwilli420]

Nice job on the rear hoop. That's how I did mine and now you have the strength back and won't have any tire interference like the guys with lay down hoops.

[riffman12]

thanks guys. I'm very happy with it.

What's the best way to paint the hoop and surrounding area? I used some appliance epoxy paint on my forks that I was happy with - sticks to anything and very hard wearing.

Am I better off doing a full on primer + paint combo?

[SOHC4 Cafe Racer Fan]

The rest of the frame looks fairly clean (not entirely sure from the photos).  Did you paint the rest of the frame or is it original?  Primer and a good epoxy paint should seal the affected area, but it might be difficult to get complete coverage.  If you are going to spot paint it, I would at a minimum, remove the oil tank so you can spray reward and up at the welded area.  If you are anal and have the time, paint the whole she-bang.