'81 CB750C "Rock-It"

[Hoosier Daddy]

easyrider12 wrote

OMG!  I can see it now- HDC (hoosier daddy choppers)

LOL! Actually, I been kinda working on that. My true life last name is Fortress and that is what everyone around these parts calls me. So...

shinyribs wrote

....but I'm all done with building bikes. Once I finish the current one I'm calling it quits.

Suuuurrrre you are...  

[TOOLS1]

shinyribs wrote

lol   HDC

Nice lift Hoosier. I'd love to have one of those,but I'm all done with building bikes. Once I finish the current one I'm calling it quits.

Yea right.
TOOLS

[shinyribs]

Well,the chopper needs some love. But a redo is not an actual 'build'. I got too much junk now. And an Olds that's in need of a Cummins

Alright, back on topic!

[Hoosier Daddy]

OK then, here is today's installment.

After poking around on the interwebz I decided on a pattern for drilling the rotors. 8 row spiral with 5 holes in each row. Set down with a piece of cardboard, protractor, compass and ruler with the rotors for size layout.



Used a spring loaded auto-punch and transfered the pattern to the rotors back side.
 


Then with a cobalt 5/32" bit in my little benchtop drill press I drilled the pilot holes. Don't let the dry rotor fool you, I lightly "dimple" the punch marks cafully to locate and make them easier to see, especially when the chips / spirals cover the work... then I use cutting fluid for the actual slow drilling of the through holes.



... and then to the final size with my 15/64" TIN bit from my "good" drill index (1/4" has seen better days).

 

[shinyribs]

Very nice! Wanna do my rear disc for me? Is it as hard of a material as people let on? What speed did you run your press at?

[Hoosier Daddy]

 Dude, If you are serious, I'd do it... but the cost of postage you can do it yourself AND buy some beer.
 If you have a sharp, good bit it is so easy! This is the 3rd set I've drilled and each has been a piece of cake. The key is not to abuse your tool and take your time with a sharp cobalt / TIN drill bit. Less than $5 will get you two brand spanking new cobalt bits, one in a pilot and the other a final size and you could do a dozen rotors without trouble. I cut the last hole as nice and easy as the first.
 Those guy's that say it took them 3 bits to do a set of rotors are either using junk HS bits, not using any fluid, or they are trying to PUSH it through the rotor way too hard and smokin the bit.
 Drill is set at the lowest speed and literally no pressure on the handle, just the weight of my hand and it dropped slowly through giving nice curlies. Drilling 80 holes twice I had time to I test it and see just how light I could go and still cut.

 This set doesn't need it, so I'll show you now how I resurface rotors that some people say you can't do, maybe not cut on a lathe witout chattering.
 But a 80g sanding disc on a 4" Roloc pad using the same bench top drill press... With the right handle pressure the rotor actually slowly spins on the plywood and gives a nice swirl pattern.
 

 

[shinyribs]

I am serious...seriously lazy! Nah,I got 10 holes drilled toady after seeing this post^^^. You're right,they do drill easy. Cobalt bits in my 'hood cost ~$10 for a 1/4'' though.

I like your mill! I use the same method when I scuff up rotors,too.Except I mount it to a spare whell I have with the axle clamped in the vice. It'll build up some serious speed if you let it!

[Lucky 1]

Great job you are dong.
Good thing you rescued it from a car person.

[Lucky 1]

Good winter project to do while watching a movie.

[alfa750]

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[shinyribs]

...when i break all my bits...

[alfa750]

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[Hoosier Daddy]

Thanks Alpha!
Check THIS out, almost got me a roller last night!




Lighting sucks for photos in this corner of the shop,,, she looks even better in person.
Next I need to work on the kickstand so I can get her on the lift.

[Johnnylevi]

woah that looks sweet!  I'm really diggin that red. what kind of tires are those?

[shinyribs]

Sweeeeeet!   Avons?

[Hoosier Daddy]

shinyribs wrote

Sweeeeeet!   Avons?

Well... uhm... no.
Avons are way too rich for my wallet. These are Shinko 712's.
I have read the reviews, bought them for the Suzuki, and have good experiance with them like many others reported.
 When I was checking on them the first time around I learned they are cast from the now defunct Yokohama tire molds and they are made with modern compounds. At $50-$65 they are good enough for me.

[shultz_1978]

Nice.  I like color on the frames You get board looking at black all the time.

The frames on my bikes are Ebony black. Has a brown and green metallic in it.

Love the red.

[shinyribs]

Embarrassing. I have 712's on my bike and didn't even recognize them Great tires IMO. I need a rear now.Once I go through another rear the front should be on it's way out,then I'd like to try a set of Shinko Ravens. Heard alot of good things about them.

[Hoko]

Nice job HD, looking a lot better now than it did in the box.

[spacetiger]

I like the effort and results!  I think the final results when finished will be impressive.

A question; did you consider swapping discs to a bigger diameter?  I think you might be able to do it and use factory parts.  Do you know the diameter of the existing discs, 276mm?

Jerry