The acid test.
Took a ride to the Severn Valley and Kinver on Saturday to try some 12%, 14% and an 18% gradient.
My Dawes is geared up to tackle a 16% according to the mythology.
Riding the flat on the way over there, I was cruising at about 15.5 mph against a 7 mph ish headwind. I will use CTC's PowerCalc for the sums so anyone can double-check my results. Power roughly 225 Watts tops.
I rode the hills seated on the saddle, at a RPE of about 6 out of 10, breathing steady but not overly labouring.
On the 12%, speed dropped to 6 mph, for 360 Watts. On the 14%, speed dropped to 5.2 mph for about the same power output. On the 18%, I couldn't stay in the saddle , stood up and struggled up the hill at 4.5 mph, and my power output went up to 380ish Watts.
My bodyweight was 89 kg. The successful climbs in a seated position using gearing calculated by myself were done at 360 Watts output. 360/89 = 4.04 Watts/kg.
So lo and behold, Jimbo has 4.04 W/kg. Marginally above a 'Half decent cyclist'.