New one to me...

[Gumby 1100_imp]

So I went for a fairly long (70 mile) ride on my CB yesterday--longest ride I've had on the bike so far--and noticed something a bit odd. Thought I'd see if anybody else has experienced this.

First half of the ride, bike feels normal. Occasional minor vibes through the bars depending on RPM, but nothing through seat or pegs--same as it's always been. Second half of the ride, though, I start feeling progressively more vibes through the bars...and then it moves into the seat....and then it's in the pegs too. Not heavy vibration, but definitely noticeable--enough that feet/butt/hands start to tingle. I was riding the same kinds of roads at the same revs as before. The air temp seemed to have come up a few degrees, and I noticed that this started after I'd spent some time in slow traffic, and then sitting at stop lights, but otherwise I couldn't see that anything had changed.

So...do you think I imagined it, or just started noticing vibration that was already there because I was getting fatigued (I still have comfort issues with the seat)...or was the bike actually vibrating more? I've ridden much longer stretches on many different bikes (virtually all of them liquid cooled), but this was a new experience for me.

Older air cooled Harleys often have to pull over in extremely hot weather and cool down, especially if they don't have the newer "parade" mode system.

Even with the oil cooler, I don't doubt that engine block and component clearances may change with heat on our CB1100. Not all parts expand at the same rate so you may not be imagining the increased vibration. A lot of engineering went into the design of this air cooled engine to prevent performance degradation due to heat, but the engineers apparently also "design-in" some retro vibration.

I may have just experienced a hint of it myself after a long stint of inner city riding.