Showing posts with label SRM Wireless Power Meter. Show all posts
Showing posts with label SRM Wireless Power Meter. Show all posts

Wednesday, July 30, 2008

SRM Wireless - It's ALIVE

So I went out to Huddart Park to do some fun and exciting hill repeats. This was my first real ride using the newly adjusted power meter. I parked at Woodside City Hall and rode out to Huddart Park (hey, I had limited time to train and riding from home would have added an additional 1:45hrs).
I constantly stared at my Garmin's power display, checking to see if the power reading matched my RPE. At first the power reading seemed low, but I was still warming up and my legs were pretty tired from the previous day's strength training. Things seemed more accurate once I hit the first hill. I was really relieved.
I rode up Kings Mtn. to the Huddart Park gate. My power still seemed accurate during my ascent. However, it did seem slightly higher, maybe 10 watts, than my old SRM. That could be due to a slight bump in my fitness from all the hard training I've been doing ;)
Well I knocked out my 5 minute hill intervals. The goal of the workout was to do two sets of 1-3 five minute zone 5 intervals.
My first interval was my strongest. I just went out and hit the hill hard. I didn't look at my power meter. I just pushed myself, while trying to "unroll the carpet". I hit the the Huddart Park Gate at about 4:11 (I think my best is 4:04 at a HIT session) and kept going.
The next two intervals my legs felt swollen with lactic acid. After the third interval I was trying to think of reasons why I should call it quits, but I pushed on and knocked out the last three intevals.
My power declined a lot from my first interval, but the avg power for all the intervals were in my zone 5. I'm happy with my workout. It's the first time I've done intervals at Huddart this year. I'm especially happy my power meter is reading accurately.

Training Stats:
Elevation Gain: 4,870.0 ft
Distance: 30.91mi
Training Time: 2:01:33
Work: 1540kj

Monday, July 28, 2008

Fixing the Power

I installed my SRM Wireless Friday. The first ride with the wireless unit and Garmin 705 was Saturday's team ride. My power readings seemed to be low for the perceived effort. I thought it was either because I was fatigued (plus it was really hot), or it was because I hadn't mounted the power sensor cube correctly. The weird thing is I was using a dual set up, the wired PCV SRM computer and the wireless Garmin Edge 705. Both were giving me the same readings.
I originally mounted the power sensor over the cable guide, using one washer from a tube. That night I mounted the power sensor under the cable guide. I left the original wired power sensor in it's original place (I have glued on). When I went out for my ride Sunday my power numbers were closer to my RPE. I once again ran the dual set-up of the PCV and Edge. Both computers jived. I thought , cool problem solved. So I removed the wired set-up.
Well today when I was testing things out I wasn't getting any power reading - WTF?! I would occasionally get the Garmin to pick up the power meter, and it would register a slope, but still no cadence or power reading. Then when I reattached the wired power sensor I would get a power reading.
So I removed the wireless power sensor to see if the Garmin would pick-up the power meter; it didn't. So I figured I must have incorrectly mounted the wireless power sensor. This time I mounted it over the cable guide using two tube washers. Viola, it worked. I took my bike for a short test spin and the numbers seemed to match my RPE. Cadence was working, power was working, and I was happy.
The real test will be tomorrow when I do hill repeats. We'll see how my power numbers read while I'm going up Huddart.
So today's lesson is: If you have a Cervelo and you are installing an SRM power meter using a bottom bracket mounted power sensor, you must mount it over the cable guide to get it to read the power correctly. I recommend using two washers from in bike inner tube. You know, the ones that come on the threaded valve stems. Put two of those buggers in between the cable guide and the bottom bracket power sensor mount and run your bolt through and tighten. Problem solved.