Tag Archives: tools

Bicycle Energy Calculator

Posted by xaminmo

This is how a SWAG average power on a bike ride:
http://ns1.omnitech.net/cycle/

My assumptions, recently updated, are:
* 86F, 600′ elevation, 30% humidity, and 1 atmosphere of pressure
* 25% human efficiency (racers might be a little more, newbies a little less)
* 95% bike efficiency (Rusty bearings and flat tires would be less, race-bike better)
* 0.004 Coefficient of Rolling Resistance (Recently adjusted – on the low side for road, just to be fair).
* 0.6 Coefficient of Wind Resistance (on the drops, relatively upright, larger mass)
* 1.1 m^2 frontal surface area (I’m a big guy)
* One stop every mile (Roughly what I do in Irving).

There are such huge variances in some of these based on intarwebs scientific abstracts that I’m not even sure if this is valid. Whenever I get a power meter, I’ll tweak this to be more accurate. I may get a couple different sized people to ride my bike for comparison. That won’t show any of the Coefficients of Friction directly, nor human or bike efficiencies, or any of these numbers.

There are plenty of other tools out there, such as:
http://www.analyticcycling.com/ForcesPower_Page.html


Tools and Shimano Gripe

Posted by xaminmo

My replacement, smaller torque wrench came in. It works. I can throw away my super-long one that does not work. I have a non-ratcheting breaker bar I’ll keep instead and not be tempted to see if it works.

I installed a Selle Respiro Moderate Men’s saddle to test out on my 50-60 mile ride tomorrow. I hope it’s not a big mistake. Maybe I should bring my old seat with me. It *seems* more comfy, but it also seems set-back too far. May need to pull it all the way forward, AND tilt it down 1-2 degrees.

Two of my bikes use Shimano bottom brackets. I found that the Shimano BB-UN55 (Bottom Bracket – crank spindle with sealed bearings) has different splines on each side. Standard, flat-bottom splines all the way into the cup on the non-drive side. All tools work okay on this. The drive side is cut into stainless steel, is tapered, and only half-way into the cup. The Park tool for this really doesn’t work. The Avenir tool is pretty decent, and got me fixed up, but it was still a pain. I have Pedro’s tool on order, which has tapered splines, and should work even better.

What would be best is if Shimano cut the spline grooves all the way down to the BB shell. Though, maybe I can take the Park tool and file the splines.

Note to self: 450-600 inch pounds for the BB shell, and 300-400 inch pounds for the crank bolt. Everything else is labelled with torque specs visible during install, but the BB specs are inside the frame during install.