Frame repair

[RichRoberts44]

Got a project bike and it came with a spare frame. Just noticed a split in the underside of the frame (It is stood up vertically in the pic). Whats the chances of getting this fixed? Will it be cost effective? Any help appreciated.

 

[reds]

by just the photo, it would be just prepping, lining it up and welding it. Simple, but would need to check frame for straight/ square and why it was cut in the first place. Too straight to be a "split"

 

[cqyqte]

Questions before I respond with an answer, what bike?, are there any butt welds on any other frame tube members?, do you have a picture showing the complete frame to give some perspective to the splits' location?

 

[RichRoberts44]

Its a 1979 cb900F. Ive been in touch with the owner who says its cut to get the engine out? Surely thats not required to pull the engine? Engine below, you can see the cut on the far side.

 

[RichRoberts44]

May have shown how much of a newbie I am having found the below illustation. Does this mean bolts go in the holes either side to clamp it together?

 

[Bert Jan]

haha its there for a reason. The lower bended piece of the frame can be detached from the frame. Its perfectly fine
You will find a similar 'crack' near the rear engine mount on the right side.
Its nearly impossible to get the engine out without taking that part out first.

no worries matey!

edit: you beat me to it

 

[RichRoberts44]

I am jumping in at the deep end trying to swim. Lesson learnt today, appreciate the help. Once Ive made some good progress I will post a project.

 

[Bert Jan]

Steel will never crack in such a perfectly straight line around a round tube anyway

 

[notlob]

That schematic you found is not the same as frame as you have.
This is a 79 CB900

 

[RichRoberts44]

Thanks Notlob. I dont suppose you have a link to download that manual?

 

[CarbsAndCylinders]

In an effort to strenghten the frame, racers have welded these together. I think it must still be possible to remove and install the engine after this mod but it is more difficult. Most guys lay the frame sideways on the floor and lower the engine into place. It's a heavy engine, with no handles so I would leave it unwelded unless you are trying to get the most out of the performance of this bike.

Brian

 

[notlob]

Thanks Notlob. I dont suppose you have a link to download that manual?

theres one for a 82 900 here, engine apart from can chain tentioners are the same, and this later one has rubber engine mounts
http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=685

The parts diagrams above are here
http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=685

 

[cqyqte]

On the humorous side, check out the Do The Ton picture header! There's a picture of the split style frame in the header, observant aren't we???