Topic: The Runcible Racer - maduncle's CB450 project

[Flying J]

Holy crap Maduncle, you bought that pile of crap out of the dessert and shipped it all the way down there? Your nuts.     Looking good and your super lucky to know somebody with a boring bar. It cost me $80 a hole to do a 3mm over bore. I just found this thread so ill jump on and follow.

[maduncle]

Holy crap Maduncle, you bought that pile of crap out of the dessert and shipped it all the way down there? Your nuts.     Looking good and your super lucky to know somebody with a boring bar. It cost me $80 a hole to do a 3mm over bore. I just found this thread so ill jump on and follow.

Ha!

Like any real long term project - buying the bike is the cheapest part!

End of the day I will have a mostly restored but slightly modded CB450 Black Bomber here in Australia, and it will be one of the very few around.

As far as the boring costs, my mate Glen has that covered - right Terry?

[Terry in Australia]

Yep, who said alcohol and operating machinery don't mix? Ha ha, Cheers, Terry.

[Brown Bomber]

Looks great!, I love all the shiny stuff.

Subscribed

[maduncle]

Busy couple of hours in the shed last night.

I check measured all the clutch plates and they were all very good, they all measured as if they were new (and they look new too). The clutch springs on the other hand - all at 38mm uncompressed, so I will be buying a new set soon. I moved to the other side and installed the starter gear wheel and rotor on the crank, I now need to get my rebuilt starter motor tested. It does not turn freely and I suspect I need to work on it some more, unless applying voltage is what is required to make it turn freely and it is just turning rough without power.

I also split the new cam chain and installed it, and tied it off good and secure so it does not slide inside during the rebuild. When I opened the cam chain box and pulled out a continuous chain and a soft link I did have a little freak out moment, but I reasoned that the process I needed to use was to cut one link and remove it, and then at a later stage use the soft link provided to do up the chain again. Or at least I hope that is what I was supposed to do!

I was hoping to get the head studs installed in the crankcase and I wanted to clean up the thread first, but it is not standard pitch 10mm thread - I think it is 10x1, so I will need to go out and buy the right size tap and die to clean them up.

Question time folks - when installing the head studs, just how tight do they need to be and how do you apply torque to them? Should I use some Loctite on the thread?

Finally - I am hunting for a fork brace, so I installed the front forks into the tiples and measured them up. CL450K1 forks with external springs measure at 117mm inside edge to inside edge at the top of the fork lower, and the fork lowwers measure 55mm in diameter. Hopefully Superbrace have a model that will fit - otherwise I will be making my own.

Not a bad couple of hours work.

[maduncle]

I have wheels.

All laced up with new stainless steel spokes and fitted with some nice new 'period correct' tyres.

[Terry in Australia]

Nice!

[maduncle]

Nice!

Interesting point - your CB750 front rim that had a disc brake hub needed to have each spoke hole 'tweaked' to re-set the direction to match the angle of the spoke for the drum hub. The wheel builder did all this by hand without cracking the chrome.

And by the way - I met John at Total Tools this morning and we had a great old yak about how mad we both are.

[Terry in Australia]

No worries, John's a great guy, isn't he? How did the wheel builder guy "tweak" the spoke holes? Cheers, Terry.  

[maduncle]

No worries, John's a great guy, isn't he? How did the wheel builder guy "tweak" the spoke holes? Cheers, Terry.

Not entirely sure, but something to do with adjusting the angle of the rim hole to the angle that the spoke leaves the rim - I didn't quite understand it when he explained it on the phone but it has something to do with affecting the look of the line of the spoke from where it leaves the rim.

Could be utter #@ap, but then again - he has been doing wheels for decades.

[Terry in Australia]

Nah, it's probably not crap, the bigger OD of the drum brake hub causes the spoke angle to be different from the disc hub, so I'm guessing that he probably used a rotary file to adjust the angle of the holes. Cheers, Terry.

[maduncle]

Slowly getting there.

Today I tested my starter motor and it was obvious the bearing was shot, so I pulled it apart and got a new bearing just up the road (lucky they had 17x35 bearings in stock).

Put the stater motor back together and all is good.



Fitted it to the engine along with a few other bits and covered it over as I won't be getting near it again until I get back from the USA in August.

[maduncle]

Back in Australia and back into the Runcible Racer project.

I have my frame, tank and seat pan back home now so I am working out the precise seat location on the frame, and deciding if I need to trim the seat pan down in length or not.









I think I can keep the seat pan as it is.

The front edge of the pan tucks well over the rear of the tank, and the overhang is not too much at the rear. I can set the licence plate holder slightly back and under the pan with a light over the plate fitted up under the pan. I will probably put the tail light into the rear of the pan.

I will get the pan a little lower onto the frame than shown here, as the upholstery will come over the rear of the tank slightly too. I am going to mock up all steel work in cardboard first to get the seat location just right, then take the frame with mocked up cardboard parts attached to a motorcycle frame modifier near me.

My wife looked at this set up in the shed and said "that's a lot of dove grey".

[maduncle]

I am really glad I got my frame back untouched - as I have spent the last few days designing and redesigning the seat mount and electrical tray.

At this stage - I plan to get someone with a bit of welding skill to weld two flat plates across the frame rails where the seat pan will mount, using 3x40mm steel (or 1/8" x 1 1/2" for you imperial folk). Then I will fix two strips of wood under the fibreglass seat pan where they will sit over the two steel strips. I have found that a standard timber profile is the right size already. The two timber strips will have 'nutserts' in them so you can then put hex insert bolts up through holes in the metal strips into the nutserts in the timber to hold the seat in place.

As for the rear - given the rear end is still stock, I have an opportunity to run a length of threaded rod from one bolt hole to the other in the tabs on the end of the frame. I am then going to design an electrics tray that attaches using the threaded rod as a pivot and somehow locks or bolts in place. Then I can (in theory) access all electricals by undoing one bolt and having the tray 'hinge' down' from under the cafe seat and rest on the tyre.

I have tested the full length seat pan for ride comfort and decided I need to keep the full length of the pan. With me on the bike and my legs in position where the rearsets will be, my arse was rubbing the rear of the seat pan and my kness were in the right spot for the knee rubbers on the tank. (Six foot two rider!)

But if I feel the seat pan looks too bulky on the bike, I might cut some of the material out of the bottom flat edge of the cafe hump and curve it up a bit (maybe just an inch off) so the seat looks lighter without the flat line running right through to the rear.

Best news is - I got my big box of shiny goodies from DCC...

Bad news is - the CB450 clutch springs I got from DCC don't fit a Bomber six spring clutch - they are too wide, so I am back on the hunt for CB450K0 clutch springs.

[Terry in Australia]

Looks like you're putting a lot of thought into it Cliff, well done. Is the seat pan too narrow to fit over the top of the frame rails, hence the need for the lump of wood to go between the pan and the frame? What's the OD of the clutch springs? I've got a set of 6 new Barnett clutch springs here, I think they're for a DOHC 750, but are narrower than CB750 springs? Cheers, Terry.

[maduncle]

Looks like you're putting a lot of thought into it Cliff, well done. Is the seat pan too narrow to fit over the top of the frame rails, hence the need for the lump of wood to go between the pan and the frame? What's the OD of the clutch springs? I've got a set of 6 new Barnett clutch springs here, I think they're for a DOHC 750, but are narrower than CB750 springs? Cheers, Terry.

Hi Terry, the seat pan is wider than the frame rails but I want it to sit just above them, hence the timber spacer under the pan. Plus the timber provides some meat to fix to.

I have ordered six clutch springs already, so thanks for the offer mate but I will wait for my springs.

Lessons learnt from last time - take your time on each stage and stop and think about it before rushing in.

[Terry in Australia]

And do as much of the work as you can, it really keeps the costs down!

[maduncle]

Oh I am doing that all right!

Got offered a metal lathe today at a throw away price, but I have absolutely nowhere to put it until I can use it!!!

[Terry in Australia]

What's a metal large, and can I have it?

[maduncle]

What's a metal large, and can I have it?

Damn predictive text!

"lathe" - not "large".

[Terry in Australia]

Ok, what sort of lathe, and how much?

[Flying J]

I have a similar issue. i have money for a lathe but nowhere to keep it. I keep trying to talk different friends into letting me keep it at their house. 

[maduncle]

Ok, what sort of lathe, and how much?

Um...

I will find out.

[Terry in Australia]

Okey dokey, I'm interested!

[maduncle]

Sundays efforts.







I ended up trimming 40mm out of the front end of the seat pan. The seat hump diagonal in the pan now lines up with the diagonal in the frame below. I am also using 6mm ply under the seat pan to set it at just the right height to line up with the tank.

I also notched the seat pan so it tucks in around the tank mount, I will be able to hide all that messy stuff at the back of the tank when I get the seat upholstered. And I curved the front bottom corners of the seat pan to match the tank. I will probably take some out of the bottom of the seat hump, just to lighten the look.

Then I had to see how the very sexy Dime City Cycles rear sets looked. They will mount up through the passenger foot peg mounting holes and sit in the right place for me to use them.