[Znabb]

I'm planning on using my CB450 K5 forks with a custom built 19" drum brake wheel. Perhaps silly by I can't get myself to mount a disc brake front wheel on a Bomber.

 

[GAMD5]

Hi Ronny ,Nice to see you write that & glad to see you back.RegardsChris.

 

[Znabb]

Hi Ronny ,Nice to see you write that & glad to see you back.RegardsChris.

Thank you Chris.

 

[nigelrharris03]

Pics of Rear frame loop and relation to mudguard

Hope these help Ronny. The gap between the hoop and the mudguard is a constant 7mm

 

[Znabb]

That's a big help, thanks a million Nigel!!
I'll try to calculate the height of the arc/loop from your pictures so I can recreate it on my frame.

 

[maduncle]

Put a call out on Facebook for some hipster who has hacked the back end off his bomber to weld in a 'tail hoop' and see if you can get the original piece back. That is exactly what I did (mind you I knew a guy who was doing this already) and I got my race frame back to stock.

 

[Znabb]

I suspect very few youngsters have the money to hack up Bombers Maduncle.

Anybody here on the forum that has a bare CB450 KO Black Bomber frame and are willing to help me measure the inner height and thickness of the rear frame loop/bracket since mine is cut off?

 

[maduncle]

Sad thing is - so many folk don't know they are hacking up a black bomber until after.

 

[austin.sullivan]

Cool looking build. Looks like you have the same delema as I. A bomber frame with almost enough parts

I measured the Thickness to be 8.8 mm on the edges. It looks to be flattened tubestock because of the weld and it's thick on edges thinner in center. At the tube at the weld is 16 mm thick.

I'm measuring a height of 64 mm off of the top of the tubes

I put up a picture to show you what I mean about the weld

j

 

[Znabb]

Thank you very much Austin for your info and picture. Very valuable info to me!

 

[bilbikek411]

'Brutus' is going to be a Big Dog when you're finished w/ the project , What will you have to feed that machine(aside from feeding him 'many long Rides') to keep it happy ?? :grin:

 

[Znabb]

'Brutus' is going to be a Big Dog when you're finished w/ the project , What will you have to feed that machine(aside from feeding him 'many long Rides') to keep it happy ?? :grin:

Besides petrol it will probably occasionally suck in a small bird or two through the carbs.

 

[bilbikek411]

Ronny,
Will you set it up more for 'overdrive tall final gearing' ? or will that motor be able to redline ?

 

[otr002]

Ronny i have a rear loop that was removed from a K2 if that is the same or similar, it's yours for the cost of postage, i also have some 0.75 CB500t NOS pistons…

PM me

Rod

 

[Znabb]

Bilbikek411, it will hopefully be a low revving engine with good torque on low revs.

Rod, good to hear from you my friend! Very kind of you to offer me a K2 frame loop but unfortunately the Bomber loop is not similar to any other 450 model. It's more like a tube pressed into an oval shape and then turned into a loop. Very strange design. I will have to try to make one by hand. Regarding pistons I'm going to use 74mm over size ones but again, thanks for your kind offer.

 

[bilbikek411]

Ronny,
The CB500T's have always been regarded by me as a 'Torque Monster' and for you to create a 600cc version of it I Now understand why you call the 'big dog' Brutus !

 

[LiamG6]

Hi Ronny, I'm Liam, new member here, I just found this thread, are you still building this engine? I am building a very similar engine, using 500T bottom end with 450K4 cylinders and head with a THR 74mm piston. Very curious to see how you are going with it and if you are going to complete it. What you are planning is exactly what I want, basically a low revving torque monster with a broad torque curve and peak torque lower in the RPM range than the stock 450 (although I see jensens dyno run has almost peak torque at 2700rpm and pretty flat right through to the peak at higher rpms which is very encouraging, hope to maintain that curve even after all these modifications).

I'm very tempted to deck the cylinders 2mm lower to have the same piston deck height as the stock 500t piston, but this really bumps the 74mm THR piston compression right up to about 12.7:1, I think it's just too much for this old air cooled engine for street use, even if it had a cappellini oil pump and oil cooler this thing would be just too hot and hard to tune with 12.7:1 CR, I think I'll have to get the piston crown machined down to get back to about 10.5-11.5:1 CR.

Love the name, brutus, very apt. I was thinking of calling mine "One-two punch" because of the rapid 180 degree firing order being like two punches in quick succession, and this being a 557cc it will pack a bit of a punch!

 

[Znabb]

No, I have not fallen off the face of the earth. It's just that life sometimes throws you a curved ball that you have to go out in the woods to find.

Not much have happened with the Bomber since I last wrote. I bought a complete '66 450D, yes 450D, this spring with only engine and exhausts missing. Frame number was very close to mine so I told the seller in Jersey Shore to sell his frame on Ebay. That way he would earn an extra buck and I wouldn't have all the hassle with importing and registering a complete bike. I was so happy as I now had most of the Bomber parts I was missing. Five months later there was still no parts on their way so I had to contact Paypals legal department and luckily got my money back.


First things to fix is the sawed off rear frame loop and steering bearing seats.

My welding skills are not great but I think the replica rear frame loop I made turned out quite well. Not very easy to fabric as the profile is oval (think Milwaukee Mile) but the ends are tri ovals (think Daytona).

I scavenged the steering bearing seats from an old K5 frame I had. It was already modified so I let it donate some parts before it went to the scrap yard (frame tubes was for example used to elongate a friends old 50's Triumph swing arm but that's another story). My friend and garage buddy Jorgen (master welder for over 30 years and magic metal worker) helped me welding the bearing seats as I didn't want them to come loose after a hard bump or heavy brake.

So now, when the frame, is finished it's time to start looking at the 500T engine. I stated in the beginning that it'll be a 600 cc monster but since I don't know anything about the engine I thought it would be wise to assemble it in stock configuration the first season to verify that it's healthy. That way I will also be able to notice the difference between stock pistons and THR 74mm high compression ones.



First test ride on the Bomber.

Is it only me that can't see the photos above?
EDIT: They seems to be visible now.

 

[JamesPal]

Hi Ronny, good to hear from you. I don't see the pictures either. Keep us posted.

 

[HerrDeacon]

Wow, that is one quiet bike, super smooth Nice work on the welding, impressive.

Real nice to see you back at it Ronny. I had a long period off as well, life has a way of inflicting its own will on you and we have to deal with it and ride it out. Makes coming back all the more refreshing though.