Ergo comparison
Can an average man ride a smaller frame comfortably? As it turns out, yes. After a few adjustments, I’ve settled into (what is apparently) a 50 cm frame quite well. Fixing and riding this old steelie has been a real pleasure, but I wondered how a 5’10” man could fit so well on a bike designed for a shorter person. So I made a few measurements. Some of the results surprised me.

The bikes: A 2009 56 cm Tarmac all-carbon Comp, standard crank, 17 lbs
vs.
1980 50 cm Nishiki steel frame Sport. 27 lbs.

[Disclaimer: Although I ride every day, neither Jane nor I race. The following measurements are skewed toward comfort. All dimensions are in centimeters (cm).]

Floor to top/seat: Tarmac = 99. Nishiki = 97

Floor to handlebar: Tarmac = 97. Nishiki = 93

Pedal ground clearance: Tarmac = 9. Nishiki = 12.

BB to top/seat: Tarmac = 75. Nishiki = 73.

Maximum extension, top of seat to bottom of downstroke: Tarmac = 91. Nishiki = 88

Horz. Offset, crank to bottom of seatpost: Tarmac = 16. Nishiki = 16.

Horz. Offset, crank to top of seatpost: Tarmac = 20. Nishiki = 20.

Top/seatpost to handlebar: Tarmac = 66. Nishiki = 62
[This is one difference I can feel. DB]

Top/seatpost to back/hoods: Tarmac = 79. Nishiki = 75.

Wheelbase: Tarmac = 99. Nishiki = 103. [!! DB]

Top tube length: Tarmac = 56. Nishiki = 56

Seat tube length (BB to top/tube): Tarmac = 55. Nishiki = 50.

Downtube length: Tarmac = 64. Nishiki = 61

Axle height: Tarmac = 34. Nishiki = 35.

Handlebar width: Tarmac = 42. Nishiki = 40.

Unlike the Tarmac, the stem and stem extension on the Nishiki are a single piece, as they are on all these older bikes, apparently. If I can find such a piece with a slightly longer extension, I may like it even more. DB