Advice On Choosing Exhaust Pipes And More - Tech Questions & Answers

Perplexed by pipes
Q: Thank you for the years of knowledge shared and for lessening the frustration many of us might have experienced without your expertise.

I am in the process of having exhaust pipes installed on my Vulcan 800 Classic. I want a nice purr/rumble sound (though not excessive or annoying to the masses) and a pipe that gives stable performance. I thought Cobra was the best choice due to my prior ownership of a Classic that already had the pipes on when I purchased it. However, I recently received a recommendation to consider Hard-Krome pipes due to their sound and little, if no, bluing.

Could you give some advice on how to determine sound or other tips that may assist me in making a good choice?
Via e-mail

A: With a buildup like that, I'm ready to come to your house and install the pipes for you. And in reality that'd probably be easier than providing a definitive answer to your question. The problem is that it's almost impossible to determine how loud a given pipe will be or what kind of tone it has without actually listening to one in the flesh. Some makers do have sound bites on their Web sites, but frankly, I haven't found them that helpful. Your best bet would be to try to find someone running the pipes you'd like, preferably on the same type of bike, and take a listen. But failing that, I can only suggest you check out some of the forums and get a few opinions on the pipes you're interested in or maybe ask at your local shop and find out which pipes are the most popular for your bike. That being said, both Hard-Krome and Cobra make very good pipes, so I don't think you can go wrong with either one.

Water Woes
Q: I own a 1995 Triumph Thunderbird. I washed it, and now it runs and idles rough. Before, the bike ran fine. Any idea what part I could have possibly ruined during the simple act of washing my motorcycle? The upper rpm is smooth once I get past the sputtering when starting out.
Marc Scott
Via e-mail

A: From your description, it sounds like water has made its way into one or more of your Triumph's float bowls. I'd drain the bowls to start with, although you may have to go so far as to remove them and give everything a good cleaning. Water may also have found its way into the ignition system at the spark plugs, so if cleaning the carbs doesn't help, pull the plugs, clean them and the high-tension caps, and seal everything up with dielectric grease. You should also check the air filter, just to make sure there's no water trapped in it and give the switches a shot of WD-40 to chase away any errant moisture.

A radial solution?
Q: I own a 2005 Yamaha Royal Star Tour Deluxe. It came from the factory equipped with Bridgestone bias-ply tires. These tires now have 4300 miles on them and howl like crazy. On the straight, they're not too bad, but on the turns, they really holler. I want to change tires and have been told by one dealer that radials are not recommended. I would like to know one solid reason why I couldn't safely go to radial tires, like 205 Dunlops. My bike uses 150-80/16 on the front and 150-90/15 on the rear.
Via e-mail

A: The most solid reason I can think of is because neither Yamaha nor Dunlop condone replacing a bias-belt tire with a radial, or vice-versa for that matter. Here's the 411:

Bias belt and radial tires are two completely different animals. They react to the road in contrasting ways and impart dissimilar cornering stresses to the motorcycle-a bike designed to work with one type of tire generally doesn't work nearly as well with the other. Since your bike wasn't intended to use radials, installing them could affect handling, stability and safety for the worse (the operative word here being "could"). You may also install them and think they're the best things since sliced bread. But since neither Yamaha nor Dunlop approves a radial for your bike, I'd say the smart bet would be to stick to a bias-belt design, although there's no harm in trying another brand of tire if you don't like the Bridgestones.

Lowdown on lowering
Q: What are the advantages and disadvantages of installing a lowering kit on a cruising motorcycle, especially with regard to handling?
Rodney Nichols
Via e-mail

A: Unless special circumstances are involved, lowering or "slamming" a cruiser is primarily a cosmetic modification, and in all candor, I'd be hard-pressed to think of any real advantages you'd gain by doing so. Lowering a cruiser will almost certainly impact handling for the worse simply because it reduces ground clearance.

Fin-agains wake
Q: Do the fins on liquid-cooled V-twin engines significantly contribute to engine cooling or are they primarily ornamental?
Al LaPrade

A: Since a finless barrel always looks a little odd, bikes that use the engine as a focal point (as most cruisers do) normally have residual fins cast into the cylinders to provide a little more curb appeal. But as you surmise, their contribution to the cooling process is negligible at best. When engine styling isn't an issue -think off-road and hardcore sportbikes-the barrels are generally left smooth as a baby's butt.