We decided to do the Metcalf Mauler today from the trail head in Morgan Hill. That gives us about 10 miles of riding to the offical start of the ride in San Jose, and total ride of 46 miles. All the way up we had a stiff head wind but the temperature was pleasant.

Once the ride started we were now headed south on Santa Teresa. With the tail wind, we zipped by all the fast riders, who jumped on our wheel, as we took the speed up to 30 mph for the section to Bailey Ave. We all took Bailey over to Malech where we once again had the headwind. At Metcalf we turned right for the 1,000 feet climb.

There are markings at the start of the climb and at the top where we often keep track of our time to see how well we do. Today we set a new personal tandem record, making the climb in 17 minutes and 30 seconds. That is faster than many of the riders in today’s group. I guess we just were inspired by all the watching of the Tour de France and wanted to go out and climb some hills. Both of us took our heart rate up in the high 160′s for part of the climb. Ann’s heart rate when into the high 160′s at one point. Here is the data from Franz’ heart rate monitor. You can see he averaged 168 bpm with a maximum of 172. Also note the split time was 17:30. That measured section has an average grade of 10% so it is rather steep.

Franz was clearing in the “red zone” for most of the climb (the portion between the split No. 1 and No. 2) on this graph.

Here are the same charts from two weeks earlier when Franz did the same climb on his single bike. Then he did the climb in 14:31 and had a slightly higher average heart rate of 175, maximum of 177.

Using our combined weight, the weight of our tandem, and our time, we can calculate our combined power input:

Power required to overcome gravitational resistance: 390 watts.
Power required to overcome rolling resistance: 18 watts.
Power required to overcome aerodynamic resistance: 4 watts.
Total power required: 412 watts (about 3.5 watts per kg).

From the July 1st cimb on a single bike, we can calculate for Franz that he puts out 266 watts on that climb (4.2 watts per kg). Accounting for the difference in heart rate between July 1st and July 15th, we can estimate he was putting out 250 watts on July 15th tandem climb. Therefore Ann was averaging 160 watts (3 watts per kg). Very impressive! On her single bike she would be able to do the climb in about 20 minutes with that power input. Of course we come back to reality when we watch the Tour de France where they have some of the professional cyclists wired and you can see how many watts they are putting out on their climbs. In any case, we claim the age group record for climbing Metcalf on a Tandem.

While descending on the backside our chain came off the crank so we had to stop and get it back on. We were able to catch some of the riders before the next regroup. Then it was for a fast descent down San Felipe.

After the ride we had a nice ride back to the car along the bike trail, aided with a nice tailwind. It was a very fun ride.

Categories: Cycling Group Rides, Cycling with Family
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