With modern carbon bikes it doesn’t happen near as often. The flex in steel bikes made them a natural candidate for wobble. Larger frame sizes in particular are vulnerable since most manufacturers do not engineer each size to account for the various fit and handling characteristics - speed wobble, fit or otherwise.
Life is too short today to own a bike that is vulnerable to wobble on fast descents. Certainly for me anyway, since I still ride in the mountains quite a bit. I can barrel down a mountain at 50+ eating lunch on my Spec Tarmac and it is just stable as a rock. I am on a 58 though, so it’s not their largest frame. And I run D/A wheels, which are not flimsy.
The System Six should be a good bike, but it is a 60. I would try a different set of wheels, double check headset tightness, and if no luck then just move on to another bike. Having to change your descending position or clamp the top tube with your knees is just stupid. Don’t compromise your riding skills, get a bike that doesn’t wobble. I suspect most newer carbon bikes don’t. I can virtually assure you a 58 Tarmac doesn’t.
Life is too short today to own a bike that is vulnerable to wobble on fast descents. Certainly for me anyway, since I still ride in the mountains quite a bit. I can barrel down a mountain at 50+ eating lunch on my Spec Tarmac and it is just stable as a rock. I am on a 58 though, so it’s not their largest frame. And I run D/A wheels, which are not flimsy.
The System Six should be a good bike, but it is a 60. I would try a different set of wheels, double check headset tightness, and if no luck then just move on to another bike. Having to change your descending position or clamp the top tube with your knees is just stupid. Don’t compromise your riding skills, get a bike that doesn’t wobble. I suspect most newer carbon bikes don’t. I can virtually assure you a 58 Tarmac doesn’t.