Sunday, August 21, 2011

Fender Struts

Fender struts machined from 304 Stainless, 3/16" Thick, 1.5" wide. It seemed too thick when I received the material in. But in proportion the thickness of the frame tubing (1.375") the 3/16" number, is just right. I made the left side .250" longer to go around the chain. Close examination down the page, will show how the left side of the frame kicks out more than the right, from the CL of the bike. This, like most frames, is set up to accommodate 1.5" wide drive belt. In hindsight, I should have made the left side only 1/8" longer. They ended up uneven on the rear fender. 95% of people won't notice, but I did right away. Hindsight is always 20/20.
Bought the mounting tabs from the Chassis Shop. Great website as all the tabs are laid with the dimensions. Pick what you need and go from there. I am using 5/16" fasteners at top and bottom. I used double shear mostly for aesthetics. This bike will mostly like never see a passenger,  and double shear always makes welding it on the bike easy. Here is the rear view on the bike. The fender was not anywhere near constant width from the top to bottom. The nature of the original fabrication. The middle sides were parallel to each other, the top and bottom flared out. The left rear top corner of the fender is the only area where a hammer and dolly could not get into back to straight. The corner where it goes from Radius to flat, was too far over left. I made a 6" or so cut down the middle of the corner, dolly'ed the split to move the corner over, then skip welded the cut back up. Hammer and dolly back flat, grind smooth. Now even top to bottom, no flaring. Tabs are tack welded on. Threw a .040" thick washer on the between the tabs to account for paint build up. The struts will be polished or satin sanded in finish. I will probably also put nylon washers between the struts and fender to help mitigate any painting chipping or cracking as everything flexes on the shitty Michigan Roads.
Right side view. 3rd times the charm with the chain clearance. I can always cut more off, but I can't stretch metal if I cut too much off. And to be honest, the 3rd time cut was still off. Being that is a spun fender, which was never stress relieved, I have welded on it, pounded on, ground on it and it wants to go back into flat sheets. The fender from the middle of the chains until the bottom, was tweaked. Multiple well placed taps with a wood dolly and a ball peen got fender away from bottom chain, smooth to the touch all along the cut and aesthetically even from the tire edge.
Laid each strut out have their CL be in line with the rear axle. And dead vertical with a digital protractor. Hard to see in this picture, but a little bit needs to be nipped off the corner of the fender to match the round profile of the strut. Rear caliper frame tab, battery box, oil tank, seat next, in that order.