[AirAddict]

To graduate highschool, you have to complete (and pass) a massive project during your senior year. It's very extensive. Minimum of 15 hours labor, 10 page paper, huge binder with about 100 pages of logs/records you take while working, and a 25 minute presentation. But the part that makes this whole thing worth while, is that you get to pick whatever you want to do... as long as your proposel letter gets approved. It's a massive undertaking, and it takes up months on end... so i wanted to choose something that i really wanted to do, and never been done before, and that seemed worthwhile for my future (next year i'll be going to college for engineering).

So i'm building my own bike frame. I have the resources and materials (dad is an engineer so i can work in his office on CAD, and i know a couple of welders/machinists that will help me). To make things [less] simple, i'm building a singlespeed hardtail out of 4130 steel. Pretty basic geometry and all, but i need a little help on some of technical issues. just measurements now though. I'm in the process of drawing up the frame.

I tried to measure some things on a mostly sripped down frame in my basement, but my calipers are broken mumble: ) and i can't get an accurate measurement.

I need to know:

-Inner width of the head tube so the heaset cups to fit.
-What dimensions i need to build the bottom bracket shell around (what about the threads too?)
-Tabs for rear brake adapter mount (the screw's width apart, and distance from axel)
-Rear dropouts: Do most company's have a little clearance for the 135mm spaced hub? like, the frame dropout width being about 137mm so it tensions when you tighten it and becomes stiffer?

That's all i can think of for now.

This frame is going to be built around DJ/street geometry... but i don't care if it's indestructable, or really heavy or anything like that. As long as it looks nice for the presentation... i'm good.

Any help would be greatly appreciated. Thanks in advance...

 

[frznnomad]

wow they changed a few things since i did my project. 25 min presentation???? lol. good luck man.

 

[Wumpus]

Headtubes --> http://www.columbustubi.com/eng/4_4_4.htm


Tubes and stuff:

http://www.bikelugs.com/pacentiproducts.html

OR

NOVA CYCLE SUPPLY
MR. LON & JOHN KENNEDY
4111 CITRUS AVE. UNIT N.8 - 95677 ROCKLIN CA
Tel. +1-9166246549 - Fax +1-9166246550
lon-nova@mindpsring.com
http://www.novacycles.com/

 

[Biscuit]

Sounds cool and good luck.

I recommend a google search. I was thinking about building a frame a while back, a lot of info and misc parts are readily available.
You can actually buy pre-fabricated bb-shells, dropouts, etc.

*edit: damnit wumpus*

 

[SkaredShtles]

Wow. I remember doing big projects like that in college, but not in HS.

 

[frznnomad]

yeh its deffinatly quite a big undertaking. hes got the determination and the love of the sport to pull it off. it also helps that your dad is an engineer, two best friends are intro engineers, and well hes got tons of friends to help out where they can. its acctually a great project once you get done with it. i was acctually very pleased with myself when i was done and very excited to start it so hopefully he will fill the same. let me know if i can help vince.

 

[buildyourown]

-Inner width of the head tube so the heaset cups to fit.
-What dimensions i need to build the bottom bracket shell around (what about the threads too?)
-Tabs for rear brake adapter mount (the screw's width apart, and distance from axel)
-Rear dropouts: Do most company's have a little clearance for the 135mm spaced hub? like, the frame dropout width being about 137mm so it tensions when you tighten it and becomes stiffer?

.

Standard steel headtube stock is 1.5" x .083 This leaves just the right amount of material to have a shop ream it after you're done.

It's best to purchase a prethreaded BB from a frame supply place. These are usually a couple mm long so there is enough material to face off and still end up at a 68mm width.

Dimensions for the rear brake can be found at the Hayes and Magura websites.

Build the bike around 135mm. It will collapse and move a lot more than you think. You will then have to "align" the frame so the dropouts are in line with the headtube and seattube. The requires a simple homemade alignment tool an a vice. You then spread the rearend to 136mm so it's easy to get the wheel in and out.

Any more beginner questions? go here

 

[AirAddict]

wow... thanks guys. that's just what i needed. I didn't know that you could pre order specific tubing like that.

i'll be probably posting pictures along the way to show everyone how it's coming, so look for it!

 

[Biscuit]

i'll be probably posting pictures along the way to show everyone how it's coming, so look for it!

"probably" isn't the word I was hoping to hear...
looking forward to progress pics.

 

[w00dy]

Sheldonbrown.com is a great resource for info of that sort.

If you're doing an urban frame you might think about the new bb style that the bmx companies are doing where the bearings press right into the frame. That would be pretty easy to machine.