terrymorse 

9 kph up a 13% grade is a climbing rate of 3840 ft/hr. Very respectable climbing rate, congratulations.

12 kph up a 13% grade is a climbing rate of 5118 ft/hr. Hard for a mere mortal to sustain that rate. That's Euro Pro speed. I suspect you were on a slightly easier grade when you saw 12 kph. You really need to know your average speed for the climb.

I did a similar little climb called China Grade today, near the Big Basin Redwoods Park. The steep bit is about 1.25 miles (2 km) long at an average of 11%, and I averaged 7 mph (11.1 kph). I dropped down to 5.4 mph (8.7 kph) on the really steep bit, and I sped up to 10.6 mph (17 kph) on the easier bit.

With the undulations that always exist on climbs, the only useful way to measure performance is by looking at average climbing rate from bottom to top. In my example above, my climbing rate was 4066 ft/hr, and my average heart rate was 155 (85% of max., or the upper limit of my "tempo" pace). That's a solid improvement over last week, so I'm pleased. Especially since the Everest Challenge is a mere 49 days away. Yikes!

If you want to find your threshold, you'll need a climb that takes about 20 minutes to complete (ignore the time to ride downhill), and you'll need to to it twice. Pop on over to the Training and Nutrition Forum and check out the 2 x 20 Anaerobic Threshold Test. That'll do the trick.