Design Disadvantages of the CB1100

[avsbezzy_imp]

The only disadvantages for an I4 that I know of came from reading Kevin Cameron (Cycle World.) He puts some people to sleep but he did one article comparing I4s to V4s, mainly in racing applications, and since I own a V4 Interceptor I was able to stay awake for that one.

First, an I4 with a 180* crankshaft has a dead inertial moment twice every rotation as the pistons bottom out/top out at the same time. IIRC, this creates a need for beefier counterweights on the crank. Racing engines where the counterweights were lightened up too much resulted in "shuddering" at corner exit as power was applied at lower RPMs. In the V4, when two pistons are at the top/bottom of their stroke, the other two are in the middle of a stroke, resulting in continuing inertia, and the ability to use lighter counterweights.

With the heavier counterweights and a generally longer unit, the crank has much more of a gyroscopic effect, resisting turn in, and making the bike feel heavier. Again, V4s by nature have a narrower crank and produce less such turning resistance.

As Ferret mentions, the engine is wider in an I4 and can create a teeter totter effect compared to an V4, which is more centralized in the bike like a bowling ball.

Another difference between these two isn't an advantage/disadvantage, just a difference. The I4 makes its power fairly evenly with power pulses like x-o-x-o-x-o-x-o. That's a gross oversimplification, I think, but you get the idea. The V4 is more like x-x-o-o-x-x-o-o. That is also an oversimplification. In racing, the V4's gap in power pulses aided corner exit by acting like a kind of traction control as the "rests" helped the tire reconnect in moments of too much throttle while the bike is leaned over. However, in a street riding application, this has little utility.

Finally, there's the sound. An I4 can have that angry-hornet-riding-a-jet-turbine sound while a V4 has a distinctive growl often described as half of a small block Chevy. Both, frankly, are music to my ears.

Great post! Learned a lot again, Thanks.