The Chopper Compendium

Almost all of the less expensive rams and air/hydraulic benders only operate if they are on a slight incline. Take a look at http://chopperhandbook.com/vertbender.htm as it will give you some suggestions about how best to take advantage of your new setup.

I've got some better plans for a new version of my bender than you might be able to use with your ram. Send me an email.

You can get a full CNC sherline for about the same money. I have one of the import mini mills and my Sherline will work circles around it not to mention that the quality of th Sherline is about 1000% better. Don't let the small size fool you as these micro mills can do pretty big work only you have ...

Did you hear a loud 'poping' sound when you tweaked down on the fastener? If not then you most likely just opened up a crack that was already there and the 'goop' was probably some other person 'fix'. If the crack is on the 'weak' side of the boss then just seal it with J-B weld as it probably won't...

I'm going to do a build up article but I wanted to give people the full history of Harmans front ends. Jaxon did some very nice forks and I agree that he solved most of the problems inherent in the original designs but his site is dead and I'm not sure he's still building them. Hose_Dragger had a bu...

I was right in the middle of doing research for the Harman ISG forks when I noticed that the Executive Chopper site of Bill Hollands is no longer being maintained or paid for. That's weird as I talked to somebody at the shop on Friday trying to schedule a phone meeting and everything seemed normal. ...

That sketch does not look like a 55-degree rake angle. More like a 40.

Just as a side note. On long springers it's pretty typical that about 80% of the perceived suspension comes from the legs flexing which is just to bad but almost unavoidable unless you're using 2-inch diameter legs. When the legs flex then the rockers and springs don't get a chance to work. You can ...

I looked at this all over again and the first diagram you posted would have been close to perfect even with the additional 10-degree rake thrown into the mix.

Forgot to add. Keep in mind that the line between the front and rear pivot points is parallel to ground for a 'stock' springer. That is a fork having around a 30-degree rake angle. As the rake angle increases the line between the points will change proportionally to keep the pivot geometry correct. ...

It worked. This is a simple way of doing the geometry for the pivot points that I was talking about. It has nothing to do with flop, trail, or axle placement. There are other ways of doing roughly the same thing but this method has stood the test of time, roughly 95 years and tens of thousands of sp...

That last answer may be hard to follow so I made a simple sketch to illustrate the concept. Hope I can post it.

The angle is actually determined by finding the pivot locations, full out and full in, that cause the least amount of deflection in the sprung leg (or spring rods) where the legs or rods run through the spring perch to minimize binding and to maximize the most direct push on the springs over their f...

That last diagram won't work as shown since the geometry between the rocker pivot points won't allow for full spring compression unless I'm reading the drawing wrong.

When the springer is fully extended, the bike up on blocks, and the wheel just hanging in mid air the line between the rear pivot and the front pivot should be parallel with the ground. This is what's called the 'fully extended position'. The front pivot point can be a little lower than the rear if ...