Sunday, July 25, 2010

Give me a ring

ACCESSORY 40: Elliptical Chainring $15.00 (used) + shipping @ Zach from BROL

I'm always looking for more efficient ways to increase efficiency of the trike giving me the edge I need for completing the Aids Life Cycle next year. Though elliptical chain rings aren't 100% well received and are one of the most controversial pieces of technology, the cost was worth a personal test. For $15 apiece, I could find out for myself the effectiveness of elliptical chain rings.

Time for the installation. Since yesterday night, I've decided to go with the Q-ring methodology. After further reading, I've found that there are too many people who recommend this for me to ignore it. The effective smaller diameter will be at the dead spot and the longer diameter will be in the power phase.

This will hopefully help me skip over the dead spot more quickly and help me enter the power phase earlier in the stroke. These are various photos of my current installation orientation of the ring. Phase one of the stroke is when the crankarms are in the power position. The chain ring is at it's longest diameter at this point.

This is the transitional phase as it approaches the dead spot.

Here's the final phase of the stroke at the dead spot. The crank arm is slightly higher than complete horizontal. The only real way to determine this is for the rider to simply sit down and go through a normal stroke to see where the leg is most extended. This will change based on boom angle, rider height, seat height, etc.

After further discussion and analysis of my setup from fellow BROL members, I've been recommended to turn the chain ring counter clockwise by one position, 70 degrees.

Before doing that, I'll review the performance and experience with the current setup. This will give me something to compare to after I make the change.

If my attempt at orientating the chain ring so that the dead spot is virtually eliminated is correct, this would mean that I'd be spending more time in the power phase. My muscles would no longer get the split second rest at the dead spot that I would get with the traditional circular ring. My setup would ask for muscle work more often.

Some have complained that the elliptical chain rings make riding more difficult. If my theory is correct, this is exactly what we'd expect. The dead spot rest is virtual removed from the equation therefore giving more opportunity to work the muscles in the rest of the stroke.

I did feel this in the real world test run of 25 miles. One additional benefit I noticed right away while going down hill was that I could go through gears more quickly. I no doubt reached higher speeds sooner than I did with the circular chain ring.

It would make sense that this would translate to a similar experience going uphill, but I can't honestly say with certainty that I experienced this. I'll have to ride a bit more. Something tells me that I was able to go up hills more easily, but I can't contribute this to the elliptical chain ring. There's too many other factors that could have made me spin up the hill. Food, rest, mood, weather. There's too many variables for me to commit to the elliptical chain ring as benefiting my spins uphill.


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