Monday, March 12, 2012

Testing, one, two, three

I took last weekend mostly off riding after a mini mental meltdown that could have been easily avoided.

After Southern Cross, I immediately began some hard rides early in the week when I should have rested and come Friday I was beat. Exhausted. Live and learn. Instead of force myself to ride, I worked on some household projects and generally took it easy.

Resting works, who would have thought? My legs came around the past week and I wanted to capitalize on my now rejuvenated limbs with a test run at the JCC. This is the only trail I can ride to from my house (around 15 minutes) and I always time it to use as a benchmark of sorts. Having the Garmin on the bike has made this much easier since it will pick out trail segments. I am always in question of how much gadgets affect my happiness when riding and the Edge 500 seems to be a positive addition so far...

Anyway, JCC is about 4 miles long with ohhhh 500 ft. or so elevation gain. Lots of switchbacks and rocks, generally just a short ass kicker of a trail. I have been shooting for a sub 24 minute time since I started riding out there years ago. Whaddaya know, Friday was the day.

23:30. It didn't seem super hard either.

Saturday I set out to do some testing with the Trans Iowa bike setup with Schwalbe Marathon Extreme tires set up tubeless on Stans rims and a 39x17 gear. I did a fairly tough loop around Birmingham with 48 miles and 4600 ft. of climbing with the bike loaded up. In three hours I was done and fairly beat. 16 mph was much faster than I expected to be on this bike and a good indicator I needed a bit easier gear.

Well, how the heck do you pick out a gear for a singlespeed? Well, there are a few ways but here is a psuedo scientific one.

I took a gander at the Rabbit Gear Calculator and plugged in a few different ratios. The first thing you have to figure out is a cadence you are comfortable with for an extended period. I knew from past races and rides done with the Powertap when I had one that this range for me was 70-80 RPM. Then match up that cadence with the planned speed for your ride and you have a gear that is in a reasonable range...voila, 39x18 should be close. This is around 58 gear inches and goes along with Guitar Ted's suggestion HERE for a range from high 50s to low 60s.

Side note on gearing: With a 39T chainring, every cog change moves the axle approximately 3mm. Adding or subtracting a link moves axle forward or backward approximately 13mm. Figure out yours via FixMeUp.

I have a White Industries 18T freewheel on the way. This one will the heavy duty trials version which I hear makes more pleasing buzzing sound affects than the standard version.

As I close in towards Iowa I will try and update more with my bike setup which actually isn't too far from done.

1 comment:

  1. according to your linkie-do, I'll have a 61.4" gear.

    That means I win.