gilespargiter
Veteran
- Location
- N Wales
Far as I can see the only thing a sloping top tube does is increase the standover height. Although their are claims that it makes the drive to the chainwheel more rigid, thus improving efficiency. It certainly does not lower the centre of gravity. The usual BB height is 10 1/2" - so if you have the correct saddle height for you - no difference. It is regarded as to dangerous to lower the BB any further because of cornering. It does not shorten the wheelbase by shortening the rear triangle - this is limited by the rear wheel to seat tube clearance, or if running wide wheels, the inner chainwheel to rear wheel clearance - hence the "repopularity" of 26" wheels I guess.
The wheelbase is altered by a balance between the seat tube angle, the headset angle and the length of the top tube and to a small extent by fork rake. Short wheelbase= (at the extremes) responsive, lively - twitchy, hard ride, and often no toe clip to wheel clearance. long wheelbase= (at the extremes)slower to respond,(easier straight line) smoother ride, - mushy handling.
So, in short it is the present fashion.
The wheelbase is altered by a balance between the seat tube angle, the headset angle and the length of the top tube and to a small extent by fork rake. Short wheelbase= (at the extremes) responsive, lively - twitchy, hard ride, and often no toe clip to wheel clearance. long wheelbase= (at the extremes)slower to respond,(easier straight line) smoother ride, - mushy handling.
So, in short it is the present fashion.