Article By: Vincent Stemp
Photos By: Derek Lloyd
Originally Published In The July 2014 Issue Of Cycle Source Magazine
Things don’t always go according to plan, but that’s a fact of life. Trapped in a mess of wires while sorting a charging issue in the middle of an ignition upgrade, my plan to put on a trick vintage tank from a ‘70’s Harley-Davidson Sprint were literally shelved. As I like to say when I see friends tricking stuff out on bikes that haven’t run in ages, “it’s hard to look cool when your bike is stuck in the garage.” But you know that sure wouldn’t keep me from welding something. It was just a matter of an opportunity coming along. That’s probably the best part about learning a new skill like welding; if it grabs your interest, you’ll start looking for chances to practice and improve all the time.
Wouldn’t you know it, an opportunity rolled up one day while I was waiting on some new ignition parts: my new co-worker Derek on his recently-resurrected ‘73 Honda CB175. After cleaning out the carbs and swapping bars and grips to suit his tastes, he was pretty happy with the bike even with just a handful of horsepower to get him down the road. But there was a little problem with the exhaust: specifically, it was missing. The bike still had the head pipes, but they ended right at the foot controls, with no mufflers of any kind to keep things quiet or torquey. Now we all know that loud pipes are cool, but they’ll also give you a permanent headache if you’re riding to work most days like Derek does. Plus, with virtually no backpressure, the little engine was barely getting out of its own way until Derek wound it up past 8,000 revs. Sheesh!
Dialing up a little backpressure wouldn’t be as easy as it was with the beater dirtbike a few issues back that just needed some holes patched and a new endcap. This bike is Derek’s pride and joy, and if he was going to let me work on his exhaust, the finished product would have to work well and look good. I had a pair of old stock mufflers laying around from a previous project, but we dismissed them as too heavy and uglier than stock replacement parts. We considered running another 12” of straight pipe from the head pipes, but there were a couple more problems. It would look ultra-clean, but we didn’t have any pipe in the right diameter, and it wouldn’t do much to add backpressure to help get the CB off the line any quicker.
Stumped, I started rummaging through the metal scrap looking for something to inspire me, or at least something to offer the gods of fabrication. I lucked out when I found a muffled exhaust tip from an air cooled VW beetle; the diameter and length was perfect and they even had built-in baffles to help us get some kick away from the lights.
I sent Derek off to find another and get them cleaned up while I set up the Lincoln Power MIG 216. Looking at the wall thickness of the pipe, I decided to fab up a quick support sleeve instead of trying to butt-join the two tubes. The support sleeves I made were slightly thicker than the wall material of the pipes themselves, so I was careful to start my arc on the thicker metal and pull it back and forth carefully to avoid burning through the thin stuff.
The finished “mufflers” look as clean as straight pipe, and make the damnedest exhaust sound you’ve ever heard; like a big bore dirtbike. While my welds are looking better and better with practice, we still wrapped the pipes once finished for a custom look.
Now we just need to get that huge stock tail light off that rear fender! But hey, it’s not my bike…