I have an 87 Schwinn Circuit w/ columbus SL tubes. Stored the OEM parts and swapped in 5700 105 grouppo that came on my 12' super6. Bike ride very nice, mutes the bumps n buzz far better than the super6 did. But its about 4lbs heavier and feels like noodles off the saddle stomping for accelerations, sprints or hills. IMO it won't replace a CF bike as far as speed goes but maybe a better distance bike if I ever replace the saddle. I still rock the white Condor saddle that came on the bike in 87