When downloading my data, wattage for intervals is displayed much lower than on my device (PT Cervo). For example yesterday I did 4 17' intervals. Wattages on the device read. 1=243 2=250 3=253 4=238. In the interval section of the "Ride Summary" GC reports 1=207 2=225 3=214 4=195
I recently sent my PT back to Cyclops for service and included the Cervo to have it checked out. They said all is well. Thus, leading my to conclude it's a GC issue.
One of the first places to look for such issues is the raw data itself. An unfortunate fact of life with PowerTap power meters is that you can get bad data from the hub. The bad data can take one of several forms such as what I call a "blip" where you get an unexplained and illogical spike in watts, a "gap" where you get an unexplained gap in duration between two observations and a "null" where you get a data observation with no value for watts. These anomalies are just facts of life with PT hubs. The question is how does the computer handle the anomaly? Basically, one has two choices: (1) interpolate the missing or apparently erroneous data and (2) ignore the data observation entirely. In my applications, I choose the latter. Once you have figured out the procedure for these anomalies, the arithmetic behind all the computed values for the handlebar computer or the post-ride analysis application is simple and straightforward. You can do all the computations in Excel. So, you can test the file yourself and figure out which computer is correct.
