Quote Originally Posted by Bethany1 View Post
I finally made a few more miles out with my Sirrus and realize that every bump, rock, and crack makes my bones jar. It's like riding on a metal roller coaster (not the smooth ones) that is stiff and rattling. It's aluminum with a carbon fork. The faster I went, the more stiff the bike became and even seemed to shimmy from side to side.

Is this a normal ride for aluminum/carbon fork frame and anything similiar to it will have the same riding properties?
While aluminum has a reputation for being more buzzy ride, the shimmy you're experiencing is not something that should be expected just because a bike is made from aluminum.

It's also worth noting that not all aluminum frames are created equal. And people have varying levels of sensitivity to "road buzz."

I've owned several aluminum-frames bikes with carbon forks and seatposts--my BMC also has carbon seat stays. Two (the LeMond and the BMC I currently still have around) are ridiculously comfortable for as long as I want to ride them, including doing back-to-back centuries. A cheaper aluminum Leader frame that I built up on my own as an experiment was extremely stiff and harsh...it didn't last long in my collection.

I've also had two bikes that had aluminum frames with steel forks. Both of those were fine (and fun) for short rides and errand running, but I probably wouldn't have taken them for any century rides. And I'll note that neither of them are currently in my stable.

Even within steel frames there are various levels of smoothness and comfort. The heaviest of my steel bikes also happens to be the stiffest of them. It's great for bombing around town, and I can stand up and hammer up a hill without feeling too much squish in the bottom bracket, but I can't say that about my other two steel bikes. The other two are more "comfy" rides, but I can definitely feel the torque in the frame on hard efforts. (FWIW, I am not a spinner. It took me a while to accept that, but I finally have. Spinning a low gear is way more uncomfortable for me than mashing a big one.)

My favorite bike as far as ride quality goes was a titanium Litespeed with carbon fork. Sadly, we could never quite get the fit dialed in on that one, so I let it go. But I've heard plenty of complaints from people who bought titanium frames who felt like they were trying to pedal on a wet noodle. *shrug*

All of that to say that before you assign bike problems to the frame material, investigate if it's something specific to your bike, the bike setup, or the frame geometry.