Frame tweak versus different tire diameters

[NutDriverRighty]

I've got what I think is a barstool racer from Baron Bob. When the steering is centered, the LF wheel/tire is about 1/4" to 1/2" off of the ground. I'm really afraid that the frame might be bent, but I wanted to look for the easy answer first. I measured the circumference of all four tires at 15# of pressure and all four are different. One of the fronts is as small as 33", one of the rears is as big as 33.625". I did L to R, F to R and wedge bias measurements and couldn't get all to equal. I can get front to rear and left to right to equal, but the wedge numbers are off. I'm really not looking forward to completely stripping the frame, but it's looking like I might have to. If the frame is tweaked, any suggestions on ways of squaring it up? Thanks.

Scott Franklin
www.NutDriver.org (http://www.NutDriver.org)
ScottF@NutDriver.org

[Fudd]

Scott, Just a thought or two. try removing all four wheels. If you have some angle iron (two pieces) put the frame on them and then take measurements from the center of the axles as well as spindles. That should tell the tale. Just a wild assed guess but if the frame is tweaked perhaps a big truck frame shop would have the presses big enough to aligne the frame. Could be too that the weldments were not placed properly prior to final welds. Pay attention to the front spindles. I'm betting one is higher than the other. If so you may be able to saw it off and re-weld it. Let us know Buddy:thumb:

[NutDriverRighty]

I'm following the same line of thinkig that you are. I've got it up on my Workmate so I know I have a flat surface. Unfortunately, I haven't been able to dedicate the time to get it flat on the frame (have to pull the engine or at least remove the engine mounting screws. If it is flat, will measure height from "ground" to axle center in front and rear to check weldments. Wondering if it could be spindles that were welded incorrectly (I doubt it as they are Margay).
As a last resort, the front of the frame is connected to the rear just in front of the engine by two longitudinal tubes. I have a friend who builds roll cages for race cars. We'll just cut the thing in half, put four rims without tires (to account for possible circumferential differences) on it, then weld it back together flat!
I'm going to get him to lower the seat height on my stool by cutting and then re-welding the legs. If we get ambitious, might go for a custom seat instead of the standard stool.

Scott Franklin
www.NutDriver.org (http://www.NutDriver.org)