The Chopper Compendium

Well, I was thinking about building a springer for my current build but changed my mind. I think a girder might fit the build better and the springer I want to build will go better on a longer bike I think. The bike I am putting this on is an 81 Ironhead Chop and it has a minimalist approach so the weight is not to much.

I am getting ready to purchase the material to start the build but have some questions.

In Gary's plans it says to use .134 wall DOM but cant seem to find it for sale. Will .120 be good enough or should I go thicker? I would like to keep it as light as possible but still strong.

I am going to use flat links and in the plans it has a different set of yokes to use with the flat links but I cant seem to figure out why. Can someone shed some light on that? The ones for flat links keep everything tighter to head tube and the plate is 1" instead of .625". Like I said trying to keep this thing as light as possible.

Also can someone shed some light on figuring trail and girder length? I got draft sight and trying to learn how to use it but havent had much luck.

I will keep you posted as I make progress

Thanks
Jake

Should have ready more of the build guide before posting up. I got some answers but created more too, haha.

It looks like I can use the .120 wall without any issues as this will be a short front end. The stock hydraulic forks have been shortened 2" to give you an idea.

As for the yokes, if I read the guide right I can use the pivot point on the yokes to change the angle of the forks to give the bike a longer look. If I wanted to do this would I put the top pivot point closer to the stem then the bottom. It looks like in the plans it has the lower one closer. I might just get some wood or something and start cutting that up and do a mock up.

actually, to help play with trail numbers, i can highly recommend a program for windows called TrailSym written by none other than our very own Rudedog. i'll email it to ya. it works with springers, girders, and regular old telescopic forks, too.

on the yoke pivot points, i believe you could move either and be just fine, just be sure you're not causing something to hit something else by doing so. keep in mind the whole build and the stuff that needs to go on later like the shock/spring mounting points.

i definitely think doing a mockup before jumping into the real thing will help you out tremendously.

good luck!
-dan

shoot, i forgot that gmail won't let me send a zip file. i'll email you a link to it.

-dan

Can I get a link too!

Drake, I had the same prob with tube sizes in my area. None of the supply houses had it but I went to a welding/fab shop and they were able to get it next day and was cheaper than if I ordered it.

Ken

HERE IS THE LINK AS HOSTED BY CHOPPERWEB

Thank Rudy

FULL INSTALL:

Download here http://www.chopperweb.info/forum/pics/T ... ll_v11.zip

Instructions:
1. Create a temp directory to unzip this file since several dependancy files will be unzipped. You can use your Download directory, but it will get clutered with these files.
2. Run the "setup.exe" and follow the instructions. If any files are flagged as replacing a newer file, use the newer file and do not install the older file. You will be prompted during the installation.

Feedback is appreciated.

Motivation ;-) One version of Clem Johnson's famous Nitro Barn Job Vincent drag bike with a girder... I believe this is @ 1965 9.52 et 151.51 mph
http://nostalgiaonwheels.blogspot.com/2 ... -drag.html

That is great inspiration, thanks for posting it. I have a MAC and I am not running a virtual machine yet. I will get that set up so I can check out that program. Thanks guys

I second the mock-up. Wood and mdf work great and are fairly inexpensive. You can address a lot of questions and issues that way on the cheap.

So has anyone ever built an aluminum girder? The yokes would be steel but thinking aluminum tubing for the legs either that or use 7/8 DOM steel, any thoughts?

This has been talked about in other threads. If you are considering using alum to save weight, don't bother.
The amount you save is very minimal, and the strength and stiffness you lose is considerable.