A story about Cranks and Cassettes…..
Contrary to popular belief this isn’t a blog entry about music, cassettes, records or CDs (although that will be a future and stunning topic Best Cycling Mix Ever!) No…this is an entry about bicycling gearing, ratios and crank lengths. Dispelling the myths (Perfect Picture)
In an attempt to shortcut hard training for LOTOJA; (butt in bike seat), I am trying to gain tactical advantage through upgrades to the bike (the easy way). By now you have figured out that Rodzilla is a tall drink of water, and I read that my climbing skills could benefit from longer cranks. Any benefit that is either rumored or true which will assist me moving 14% of a ton up Suncrest has to be considered.
Cranks are widely available in lengths from 140 mm to 175 mm, most production bicycles are equipped with 165 to 175 mm cranks. While 165 – 175 mm cranks are appropriate for the average rider of 5’ 8” to 5’ 10” in height, they may not be the best choices for a Rodzilla who is the exact height of Michael Jordan.
- Scientific Research about Crank Length http://myworldfromabicycle.blogspot.com/2010/08/dude-your-crank-lengths-fine-you-just.html
- Wives Tales about Crank Lengths http://www.polaris.net/palmk/crwives.html
- Crank Length Calculator http://www.nettally.com/palmk/crankset.html
- Custom Crank Lengths http://www.zinncycles.com/cranks.php
After reading some insights from the above links I decided to pull the trigger and purchase some longer cranks.
This is where it gets interesting. I challenge anyone out there to find a crank length of 180mm or above for a BB30 bottom bracket. Oh you found one from SRAM? Nope guess again, that model has been discontinued and isn’t listed anywhere.
So after much research I decided to eliminate the benefit of a BB30 and buy a metal adapter for $45 bucks from www.infinitecycles.com. My favorite Local Bike Shop here in Utah that specializes in Cannondales. This shouldn’t creak like the plastic converters and will increase my options to upgrade to a 180mm length.
The Next challenge was to find a 180mm crank length that wasn’t going to flex out under the pure wattage of power I was going to be applying to each stroke.
I ended up settling on a trusted name brand, the holy grail of cranks, the Shimano Dura Ace 7900. Here is where my ego wrote a check I couldn’t currently cash. I bought the 53/39 instead of the 50/34 which I am currently riding. I was convinced after the above reading that the extra 5-10% leverage gained from longer crank lengths would allow me to be able to turn the bigger gears up the mountain and benefit more on descents and flats where I currently spin out.
Side Note (Not wining any popularity contests)
I talked the Red Rider into letting me sell my older Cervelo to get the New Super Six Cannondale based on the fact that I couldn’t climb mountains on my Cervelo 53/39. Additionally my friends were tired of waiting for me at the top of just about every climb in the valley. So I got a faster climber bike.
Side note to the side note (Salt Lake Valley overview)
There are very few rides of 20 + miles that don’t have some type of 5%+ climb involved
53/39 Vs. 50/34
Look at the work I put into my rational using Sheldon’s Brown’s Gear Calculator
http://www.sheldonbrown.com/gears/. After reading the return policy on the cranks, and listening to the wisdom of my friends, and the little trip down memory lane with the Red Rider about how I couldn’t ride up any hills on the old bike, I decided to exchange them for the 50/34 and play it safe. I still have the option of changing out the cassette to a 11 – 28 which will give me a little more power on the low end.
Infinite just called me today, and told me that everything is installed, and that I need to wait for 24 hours for it to set up before I can ride. (This is where I found the time to write this blog entry)
Stay Tuned for part II…………..Rodney Longcranks (Nifty Nickname by (im)deebers
Hopefully this is where I blog about what an amazing difference these longer cranks make. Giving me more leverage and comfort, while being stiffer and lighter oh and prettier.