CB72/77 Crankshaft bearings

[SMBH]

What about a modern CB72/77 Honda.

Possibly the closest thing would be a Yamaha R3, or a Ninja 300.
If you could put up with all that plastic.

Ho my I googled Yamaha R3, Ninja 300. and you could not give one for free no offence ment but man they are ugly they may be light years ahead of a CB72/77 but I would rather have a rusty clapped out old Honda, then im an old boy and I can remember when there were NO Jap bikes on the road in the UK.

Honda shook me up when the CB72/77 was released it was love at first sight and now some 55 years on im still in love, I must be with what I have spent on this CB77 and it's still not on the road.
Honda did not call them Dreams for nothing.
I have seen a lot of road bikes come and go over my years and nothing for me looks like a CB72/77 from any angle.


BEAUTY IS IN THE EYE OF THE BEHOLDER.

[R100]

What about a modern CB72/77 Honda.

Possibly the closest thing would be a Yamaha R3, or a Ninja 300.
If you could put up with all that plastic.

Ho my I googled Yamaha R3, Ninja 300. and you could not give one for free no offence ment but man they are ugly they may be light years ahead of a CB72/77 but I would rather have a rusty clapped out old Honda, then im an old boy and I can remember when there were NO Jap bikes on the road in the UK.

Honda shook me up when the CB72/77 was released it was love at first sight and now some 55 years on im still in love, I must be with what I have spent on this CB77 and it's still not on the road.
Honda did not call them Dreams for nothing.
I have seen a lot of road bikes come and go over my years and nothing for me looks like a CB72/77 from any angle.


BEAUTY IS IN THE EYE OF THE BEHOLDER.

They are not my cup of tea either. I'm sure the engines are marvelous, but the rest of the bike does nothing for me.
Having bought a Triumph Bonneville new in '66, I'm far too old to pretend I am V.Rossi.

[G-Man]

SMBH

Early crankshafts were designed for the ball race and the crank journal was not hardened. These cranks can be identified by the radius between journal and web. Oil was fed from the oil seal side and there was no shield on the bearing.



Later ball races (020) had the shield to keep oil inside the bearing. Remember it is being fed from the seal side and the little slot is to keep the oil level no more than half full.



Roller bearings were introduced with a hardened journal and an undecut between the journal and web.



When the hardend crank journal (where the rollers run directly) gets worn or damaged Honda used the earlier ball race as a way of saving the crank. But, as you have seen, the ball-race cuts off the main oil supply. Removing the shield of the 020 bearing may let oil get to the bearing but that was the point of my 'interim' crankcase which had both oilways built in. If I understand the purpose of the shield, it is to stop oil being flung out of the bearing (when properly fed) at high revs.

If I have to retrofit a ball-race on a 'roller' crank I will cut a channel for the oil to flow in from the seal side as Honda intended.

As for a modern CB72/77 what about the latest CB500 twin?

G

Them crankcase looks like a early one with the breathing tower on the top, I think Honda got there knickers in a twist with that alternater side bearing my 1964 case has a oil feed hole that is covered by the ball bearing race when fitted or should it have a roller bearing I thought the roller bearing was fitted to the very early bikes, this make sence as it's cheaper to fit a ball than a roller bearing.
And to top it all my ball bearing race has a 6mm hole and the knock pin is stepped down to 5mm this gives the bearing plenty of room to move about so that knock pin is not there to hold the bearing.

And what is that little channel for ? oil one would think.

Well I will remove any seals on the bearings i install on that side.

So right more questions than answers perhaps Honda wanted to discourage any one in the future from restoring any of there bikes cunning them Japs.

There was a time when Honda when asked if they had any of there old GP bikes and they said no Honda has no time they do not look back only look forward that was quite a time ago, when the retro lark started they soon changed there mind when they set up a museum and scoured the world for old GP bikes to fill it.

What about a modern CB72/77 Honda.

[sprocket]

Brilliant mate, just brilliant. When your motor fails you can use all that money you saved on the wrong bearings to rebuild it. Not only did you use bearings that were not designed for that application you have also cut off their oil supply. Mr. Honda is probably spinning in his grave AND laughing his ass off. However, and I mean this sincerely, the machine work looks first rate.
Karl Hoglund

[LOUD MOUSE]

Help me with a couple of things G.
You find 1 upper case with a second small drilled hole.
Are you and can you prove a feller like myself or yourself didn't drill that hole rather than HONDA?
Does that hole have the SMALL hole restriction hole like the ones we see in all the other cases?
Any reason you don't feel that the right side bearing can be used without a cover?
I look at the left side BALL Bearing and haven't seen one with a cover on either side.
What problem is there if there isn't a cover on the right side bearing.
Another bit to be considered.
Around 1986 I got back into HONDA restorations and I didn't find many CL72 engines.
I ask John Muckintholler who owned Buena Park HONDA (retired flat track racer) if there was any reason he knew of.
His reply was "We used that 250ccc engine for flat track and the right side roller bearings didn't get enough oil and would ruin the crank".
He told me that as there were many of the CL72 engines (CA72 also) available they just replaced the engine and went to ASCOT the next race.
Made since then and even today. ......................lm

SMBH

Early crankshafts were designed for the ball race and the crank journal was not hardened. These cranks can be identified by the radius between journal and web. Oil was fed from the oil seal side and there was no shield on the bearing.



Later ball races (020) had the shield to keep oil inside the bearing. Remember it is being fed from the seal side and the little slot is to keep the oil level no more than half full.



Roller bearings were introduced with a hardened journal and an undecut between the journal and web.



When the hardend crank journal (where the rollers run directly) gets worn or damaged Honda used the earlier ball race as a way of saving the crank. But, as you have seen, the ball-race cuts off the main oil supply. Removing the shield of the 020 bearing may let oil get to the bearing but that was the point of my 'interim' crankcase which had both oilways built in. If I understand the purpose of the shield, it is to stop oil being flung out of the bearing (when properly fed) at high revs.

If I have to retrofit a ball-race on a 'roller' crank I will cut a channel for the oil to flow in from the seal side as Honda intended.

As for a modern CB72/77 what about the latest CB500 twin?

G

Them crankcase looks like a early one with the breathing tower on the top, I think Honda got there knickers in a twist with that alternater side bearing my 1964 case has a oil feed hole that is covered by the ball bearing race when fitted or should it have a roller bearing I thought the roller bearing was fitted to the very early bikes, this make sence as it's cheaper to fit a ball than a roller bearing.
And to top it all my ball bearing race has a 6mm hole and the knock pin is stepped down to 5mm this gives the bearing plenty of room to move about so that knock pin is not there to hold the bearing.

And what is that little channel for ? oil one would think.

Well I will remove any seals on the bearings i install on that side.

So right more questions than answers perhaps Honda wanted to discourage any one in the future from restoring any of there bikes cunning them Japs.

There was a time when Honda when asked if they had any of there old GP bikes and they said no Honda has no time they do not look back only look forward that was quite a time ago, when the retro lark started they soon changed there mind when they set up a museum and scoured the world for old GP bikes to fill it.

What about a modern CB72/77 Honda.