Which motorcycle has the smoothest engine?

Motorcycle magazines tend to ignore the smoothness of motorcycle engines. What is the smoothest engine you've experienced?

Honda ST1100! Rode it for 2 years. Guess why I got ride of it? With no feeling it was like riding in a car!

The smoothest bike I've ever driven was a BMW K100RS (similar to the one pictured below). It's an inline 4 oriented fore and aft rather than left to right. Kinda looks like a car engine layed over 90* on its side. I didn't like it though. Ed

the kind that does not start. i have always found smooth engines boring.

I find they all are about the same "smoothness" at 8K rpm and above..

The ST1300, ST1100, and all the Goldwings are very smooth, as is a K75. All of the K100's I've ever serviced (over 30) were buzzzbombs.

893cv wrote: The ST1300, ST1100, and all the Goldwings are very smooth, as is a K75. All of the K100's I've ever serviced (over 30) were buzzzbombs.

Interesting. The one I rode (only for 1 day) was new (a buddy's bike) and it was as smooth as a Valkyrie that I also drove for 1 day. Maybe the Beemers got shakey after they had a few miles on them. Do you have any experience with the Valkyrie? I found it to have a very smooth engine. Ed

Goldwing. Found it a bit boring, like driving a big sofa. Although, I imagine that sofa is much appreciated after couple of hundred miles or so.

The Suzuki GT380 was one smooth machine in its day, except for the passenger footpegs for some reason.

Yes, Valkyries are a goldwing derivative, and very smooth. I've mounted a few sets of tires on them, great bike for Nebraska or Kansas. BMW made a lot of changes to get the K100s smoother, new footpegs, footpeg mounts, even a recall on throttle balance at low rpm's. The K75 was able to use the output shaft as a balance shaft, and the result was a very smooth running engine with a great exhaust note. I'm still looking for a K75c to build.

650ed wrote: [Interesting. The one I rode (only for 1 day) was new (a buddy's bike) and it was as smooth as a Valkyrie that I also drove for 1 day. Maybe the Beemers got shakey after they had a few miles on them. Do you have any experience with the Valkyrie? I found it to have a very smooth engine. Ed

Inline-6 motors are said to be as smooth, or even smoother than v-8 motors. So I would imagine a KZ1300 or CBx would be silky. My old Datsun 260 had an engine smoother than an american v-8 (of which i've had several).

For the same reason 6's are smooth, small triples seem to be smoother than expected as well. I've ridden one or two GT380's, and as grumpy56 said, it was remarkably smooth.

The GL1800 goldwing is pretty darn smooth, but even with it smooth as it is when I rode my 3000 miles in 45 hrs last June, I had a completely numb right palm for 2 months after the ride. I guess just from vibration, but don't know.