915 superbike on the cheap

[DesmoBro]

916....anyway you can squeeze one more out? haha give Ducati a run for their money

 

[rockcitycafe]

Looks sweet man!

How do you form the Alum for the tank over the foam? Or do you have a wooden plug somewhere we cant see in the picture?

you don't, the foam is just for shape reference, the forming is done with conventional methods, and the pieces are laid on the foam pattern to check the shape as the piece is being worked

 

[suthern]

you don't, the foam is just for shape reference, the forming is done with conventional methods, and the pieces are laid on the foam pattern to check the shape as the piece is being worked

Sounds like there is an art to it and looks like it involves a lot of talent.

 

[rockcitycafe]

"talent" is just the result of successive error and improvement

 

[Sonreir]

“I have not failed. I've just found 10,000 ways that won't work.”
Thomas A. Edison

 

[gk45011]

Great start. Onboard with the popcorn for this one.

Gary

 

[rockcitycafe]

Crap... made the first of 4 guides, made it from bronze and got really close to the stock guide diameter (.0004" on the small side), heated up the head and tried dropping it in, went in about 3/8" and stuck... crap. tried driving it home, but it was too tight, tried driving it out but it was too tight... looks like bronze may need to be smaller than steel... argh, will probably set up the head on the bridgeport and try to tram it in to the spring seat and drill most of it out, hope the bore is ok

 

[Sonreir]

Nothing a six ton press won't fix? ;D

 

[rockcitycafe]

I think a 6 ton press would make the guide look like a golf tee

 

[rockcitycafe]

got the guides started, ordered a .260 reamer, machined the guides after removing the one I botched, the first one went in perfect, second one the same, so exciting to be able to say I made my own guides (hopefully the motor won't blow up and embarrass me)

 

[rockcitycafe]

had the tank started, didn't like it... was too round for such an angular seat so I started freeforming one today, got tons done on it since it's very flat, since this is not a machine built around looks, I like it though, since the ergonomics are totally what they should be and it will hold a good amount of gas. the swingarm is also done, rear wheel has been all machined so I won't need to find a 520 offset sprocket, had to replace one bearing on the cush drive hub with a sealed bearing because there just wasnt room for the separate grease seal

 

[canyoncarver]

Nice work on the tank, fits the lines of the seat better. More pics!

 

[rockcitycafe]

More pics, finished the axle adjusters and installed the chain, everything clears

 

[Sonreir]

That's always a nice feeling. I'm beginning to dread all the test fitting on my bike...

 

[rockcitycafe]

I think the trick was to not take much apart at a time, the front end was done at one time, back end another time, etc, that way you're never too far away from being able to see how everything fits together, I didn't even take any parts of the engine off and instead will be swapping the 915 into the bike after everything else is done and it's test ridden with the stock F motor that's already in it.

 

[rockcitycafe]

made some handlebars, the clamps mount directly to the top triple, clipons with the bars in front would have been too far forward and low to give a good riding position

 

[rockcitycafe]

playing with a fairing shape, going to go 1/4, would go full but the engine is probably going to need the air, I figure if I knock out a good shape (not a brick) it should get me some speed points, read a bit on an article someone posted on here about 70's race fairings, got some good info, hopefully this will streamline the bike in a worthwhile way

 

[canyoncarver]

Sweet fairing. I especially like the custom wood mount.......

 

[rockcitycafe]

Some more work on the fairing

 

[DreadRock]

Don't think the tape will hold that going down the road could be wrong ! Nice look man seems to fit nicely !