Topic: Re: Bigsam302's 76 CB750F (915cc): Project Helen – Running Report!

[Bigsam302]

Introduction
My name is Sam.  I've been on this site for a few years and I decided that now was as good of a time as any to finally make a build tread.  I wanted to build my own custom bike.  In the past I have only ridden sport bikes (I currently own a Ducati 1198).  I was going to buy a cruiser and customize it, but I wanted something a little different.  One day I stumbled across Cafe Racer TV and fell in love with cafe racers.  Therefore, I decided to go this route.  After reading this forum and other sites on the internet, I found a couple of bikes that I have used for my inspiration.

Inspiration
These are two of my favorite bikes.  But I have also borrowed ideas from many other places.  The first bike belongs to another member (I don't remember his name) and I love the look of it.  I wanted to make a bike similar to this one.

I also like this bike...well some parts of it.


The journey begins
I'm in the military, so I spend a lot of time traveling and deployed.  While I was stationed in Newport, RI, I found a farmer in Maine who was selling a 1976 CB750F for about $700.  I bought the 750 on accident.  As you will find, the build so far has been a road of mistakes and hard lessons learned.  Not knowing much about cafe racers, I bought the 750 thinking that it was the same as a 550, just with a bigger engine.  1st mistake. 

Here is my baby.  She appeared to be in good shape.  The owner cranked her for me and she ran pretty good.  The only problem was that it was sitting for about 3 years, so the brakes didn't work.  I didn't get a chance to ride it.



I said that buying the 750 was my first mistake, I don't think so now.  At the time I wanted a clean middle section like on my inspiration bike.  I didn't know that the 750 had a separate oil tank in the center of the frame.  My first goal was to figure out how to get the middle section clean.  After doing a little research, I contacted Benjie's Cafe Racer and asked them to build me a tank with the oil tank inside.  Here is the tank and seat section that they built for me.




My second goal was to upgrade the suspension.  I like the GSXR forks that a lot of other members used, so I decided to go that route.  I found a guy who made custom triple trees.  They looked awesome, so I decided to start disassembling my bike.

What's cool about these triple trees is that they have the same rake and trail as the 750.


Started the mock up.  Here is my bike with the new triple tree, GSXR forks, and a V-Rod headlight.


Next, I got my wheels laced.  I used the harley front hub and my original rear hub.  I have something special planned for the rear wheel.  The wheels are both 18 inch Sun Rims anodized black.  This is how my bike look after my mock up.  I wasn't 100% satisfied with the look, but you will get an idea of what it is going to look like.

For the rear, I got the widest 18in tire that I could find.  I have a AVON Roadrider 150/70-18 on the rear.  I also got a rear swingarm from a 78 CB750, which is wider.  I didn't want to run into any issues with rear wheel clearance later.

It should be a fun project.

[Bigsam302]

I did things a little backwards than most.  I installed a Gordon's Frame kit before removing the engine.  Since I'm doing most of the work in my garage on my free time, I figured that this would be the easies way.


I will be running an oil cooler.  I found a pretty cool way to mount it.  It's from a CB650


I am going to move the kickstand.  I ordered TC Bros' kickstand.




I found a rear brake from at 2000 Ducati Monster.  The rear brake arm is the exact same diameter as the 750's rear axle.  My local machine shop was able to fabricate a rear brake carrier and now I have a pretty sweet set up for my rear wheel.

[Bigsam302]

I ended up getting rid of the rear shocks that I found on ebay and had some custom shocks made from YSS.  I really like the quality of these shocks.


I bought a set of rear shock mounts from Dime City Cycles.  I plan on having the complete mount redone.


I also bought a set of rear swingarm spools so I can put my bike up on motorcycle stands.

[Bigsam302]

My Gauge

This is one of my favorite custom pieces so far.  I wanted to keep my original tachometer, but I also wanted to update it. The first thing I did was buy a Motogadge mini speedo, new gage decals, and mini LED lights.

I modified the faceplate




I ended up damaging the first face plate that I used and had to start over.  This time I decided to use a black face plate.  I painted the cases satin black and ran all of the wiring.  To finish it off, I used the gage rings from Joker Machine




I really like the way it turned out.

[Bigsam302]

I started to take my engine out of the frame.  I have big plans for the engine!  My first disappointment was splitting the engine case and finding this.

The previous owner saw that the engine case was cracked and used JB weld to hold it together.  Apparently it worked pretty well.  The rest of the engine internals looked great and it was well oiled.


I ended up buying a new case on ebay.  I cleaned it and painted it already.  I sent the crank, transmission, and other parts off to CycleX to have them reworked.  I'm waiting on them to send it back so I can start reassembling the lower case.

[Bigsam302]

Frame Mods
I found a great shop here in San Diego to help me with my welding, since I can't do it.  Sal at SC Welding and Metalworks has a lot of experience restoring old bikes and was able to do everything I wanted for my bike.  One of my first issues was with the way my tank fitted.  No offense to Benjies, but the tank's fit was horrible.  I had to have a lot of work done to get it to fit properly on the frame.  If you look at the first photo of my mock up, the tank rides really low in the front and there is a huge gap from the tank and the steering head.  I hated the way it looked.  I also had the frame braced.

Here is it's current fitment.  I like this a lot better! 

[Bigsam302]

Frame

I got the frame powdercoated satin black.  It looks awesome.  I even got a new frame VIN plate



For the swingarm, I installed bronze bushings and had the zerk fitting upgraded.


The shocks and turn signals are installed.  They came out great!


I got rid of the original triple trees that I had bought and replaced them with a set from Cognito Moto.  I think it looks a lot better.  Plus, it got ride of that horrible gap that I was talking about earlier.


I bought these forks on ebay.  After I did the mock up and rested the full weight of the bike on the front end, the forks leaked bad.  I had to send them off to get them rebuilt.  At least I know know that they will be solid.


I changed my mind about the V-Rod headlight and decided to go with a more traditional round headlight.

[Bigsam302]

I painted the rotors and installed them.


Front wheel installed.  This is overkill.  Since I had a Brembo on the rear, I decided to use Brembos up front.  I found a set on ebay and painted them black.


Here is my rear disc carrier painted and the rear brake arm modified.




Here is the Ducati rear brake rotor installed on the carrier.  You are looking at the rear side.




Rear wheel installed with rear brake arm

[Bigsam302]

I got my gauge mounted and it looks awesome!


Freshly painted oil cooler


I wanted to go with leather grips and a leather seat.  I like the old vintage look of leather.  If I don't like it later, I can easily change it.  I wrapped the grips myself.  Not bad!


We have a roller
I have the bike assembled and this is all that I can do right now.  I'm still waiting on the engine to come back from CycleX.  Then I have to send the cylinder block and cylinder head off to get machined.  I love the stance and I am happy with the way it is turning out. 


I will post updates as I get them.  My goal is to have this bike up and running before May 2015.  Wish me luck and thanks for checking out my build.  If you have any questions, please let me know.

Sam

[calj737]

Some nice ideas.

In case you didn't, the rear rotor mounting bolts need some thread lock on them. I didn't see any, but wanted to be sure to mention it.

Curious why you bought a MotoG gauge and then mounted it within a Stock tach? Why not just buy the MotoG gauge that has all the functions in it? Their ChronoClassic is a multifunction gauge with tach, speedo, info, voltage, etc... Not that yours isn't cool, just curious?

Which rearsets are you planning?

Good looking bike.

[Bigsam302]

Cal,

I did put the blue thread lock on the rear.  I just cleaned up everything.

I was going to go with the MotoG gauge, but I wanted to do something a little different.  Plus I really wanted to keep my original gauge.

As for the rearsets, I have modified 02 GSXR 750 brackets that have been modified to hold that tarozzi rear sets.

[SOHC4 Cafe Racer Fan]

Sam,

We can all relate to the try and revise/refine issues you've been through. The bike is coming along well. Some great work fitting the rear brake.

Did you send the entire motor to Cycle X or just components? What are your engine mod plans?

Don

[Bigsam302]

Sam,

We can all relate to the try and revise/refine issues you've been through. The bike is coming along well. Some great work fitting the rear brake.

Did you send the entire motor to Cycle X or just components? What are your engine mod plans?

Don

Don,

No I did not send my complete motor to Cycle X.  I'm building it myself, I just sent parts off to them.  I am building my engine in sections.  I'm starting with the bottom case, then the block, and finally the head.  Here is my engine plan.

I'm building a bullet-proof engine similar to Tweakin's build.  I'm going with a 915cc kit.  Currently at Cycle X they are lightening and balancing my crank, lightening my alternator, race cut my transmission, they lightened my rocker arms, they welded my head cover and installed cam tower stabilizers.  I ordered Carrillo connecting rods, Cycle X super clutch kit, their heavy duty primary chain and cam chain, super gasket kit, heavy duty case bolt and nut kit.  These things should be complete and mailed to me in a few weeks.

For the block, I'm sending it to Cycle X and have them bore it for the 915 pistons.  They currently don't have the bore sleeves and will not have them until December or January.  This is going to put my project on hold for a bit.  I'm also ordering their super studs and nuts combo.

The cylinder head is going to be the last part.  It is going to require the most work.  The head is going to be sent to Cycle X to have them port it (#4 option), a race cam, oversized intake and exhaust valves, new super flow valves, and Kibblewhite high performance valve springs (5mm Bee-hive conversion).

Finally, I am going with a Mikuni RS34s, and Cycle X Arc Ignition Electrical kit.

[martin99]

Good plan. The military must pay well. I take it you're single?

[Bigsam302]

No, not at all.  I have a very supportive wife.

[martin99]

Now you've given me two things to be jealous about! Enjoying the build, keep the pics coming

[calj737]

I can think of worse heroes to have than Tweakin'. His build was an absolutely top class one for certain. If you're pursuing the same level of engine mods as his, you'll be very pleased I'm sure. And the folks at CycleX do very nice work. If Mike Rieck couldn't do my work, they (or APE) would be my only other choices.

[slikwilli420]

Very cool build. I just posted my intentions for a 915 kit in my '76 SS as well, inspired by Tweakin'. There are a lot of great things going with your build and I will be watching with anticipation like many others here.

[Bigsam302]

Very cool build. I just posted my intentions for a 915 kit in my '76 SS as well, inspired by Tweakin'. There are a lot of great things going with your build and I will be watching with anticipation like many others here.

Thanks I appreciate it Slik.  That's good to hear, maybe we can compare notes.  I'm going to need all the help that I can get.  I've checked out your build and you are doing some pretty cool things as well.  I like what you did with your front brakes.  Keep up the good work!

Sam

[SOHC4 Cafe Racer Fan]

Matt and Sam,

Great inspiration courtesy of Tweakin. I'm enjoying both of your projects. Matt's wheel brake combo is inspiring me to use my AP calipers.

[Bigsam302]

I received my crank from Cycle X.  I got the Pork Chop version and it is gorgeous.  I received a bunch of other goodies like my lighted and balanced alternator, super gasket kit, manual primary chain adjuster, race cut transmission, Cycle X heavy duty primary chain, cam chain, Cycle X heavy duty case studs, etc.....



Here are my Carrillo Rods and they are pretty!


Transmission and Cycle X primary chain adjuster installed

[Bigsam302]

Now comes all the fun.  I bought Hondaman's book, I have the shop manual, and I watched assembly videos online.  I felt pretty good putting the crankcase back together.  This bastard was a pain in the a$$!  Nothing went together like it did in the videos.  But I managed to get everything installed and I used Hondabond 4 to seal the case.



I'm glad that this part is over.  The next headache was turning the engine over and reinstalling the oil drain plug.  This is where I found out that it was stripped.  I can't believe that I had missed this.  I unscrewed it and it look fine when I was breaking the engine down.  So I sent the oil pan and a bunch of other parts off to get powdercoated.  What to do now?  So I ordered a Time-Sert Kit online.  I did some research and this was the best option that I found.  The kit looked pretty good and was very simple to retap the hole and install the kit's insert.





The kit was kind of expensive, but it worked like a charm and is better than new!

[Bigsam302]

And now the fun really begins.  After fixing and reinstalling the oil pan, I decided to work on the gear shifting mechanism.  Everything went together just fine.  That's when I noticed that the main bolt that holds most of the shifter parts was bent.  I don't know if you can tell from the picture, but it is definitely bent.  I decided that it wasn't worth the hassle and ordered another one off of ebay.



With the gear shift section on hold, I decided to get my neighbor to help me drop the crankcase into the frame.  It went in pretty easy and the swingarm spools that I installed worked like a charm.









I received my gear shift parts in the mail and decided to work on that piece.  I put my wrench on the bolt and it snapped off like a toothpick.  WTF!!!  I barely even applied pressure to it and now I have to deal with this!


Now this part is on hold again.  I contacted the guy who helped me with all of my welding on the frame.  He is going to try to help me get the bolt out.  The only problem is that I have to put my bike up on my trailer and take it to his shop about 15 miles away.  I hope he can fix it.  I'm worried about it, but he is not.  Wish me luck and I'll post updates as the come!

[calj737]

No fuss. He can weld a bolt to the sheared portion, and then you turn the broken portion out. Since your case is alloy and the bolt is steel, not a problem.

I'd strongly suggest you locate a new, stainless bolt to use if possible. No more "used bolts".

[Bigsam302]

No fuss. He can weld a bolt to the sheared portion, and then you turn the broken portion out. Since your case is alloy and the bolt is steel, not a problem.

I'd strongly suggest you locate a new, stainless bolt to use if possible. No more "used bolts".

Cal, I've replaced every bolt on this bike that I can.  The only issue with this bolt is that it is a special bolt made specifically for this bike and the part is no longer available.  The new (used) one that I got off of ebay looks fine.  I hope that it will hold up