Compact Cranks continued

Compact Cranks continued, 5/29/06

It has been fun to discover something so invigorating after so many years of cycling. Very much enjoying revisiting familiar routes with a new set of gears. Thought I would share a bit more on the subject.

Climbed Kings Mountain Road out of Woodside last week. For those unfamiliar, Kings is a fairly steady climb of about 30min duration, and I would estimate grade at 5-7%. In short, a tough climb no matter how you cut it.

For most of the climb I used my 34/23 and 34/25 gears. Although I had the sense of spinning away happily, it was interesting to note that my average cadence for the climb was 80. Lolly-gagging up the climb? Hardly.

Average watts was 295, 2nd half of climb slightly higher watts as intended, average HR 10 beats below LT, time on par with other outings. Primary difference was how legs felt great at the top and continued climbing another mile or so on Skyline.

With conventional cranks my average cadence would have been in the 60s for the same effort, and my legs would have been considerably more worked. Later in the same ride was able to work a similar climb at 300+ watts and where I doubt this would have occurred if I had previously mashed my legs with a 60s cadence, and then tried to do similar or better watts yet with a 60s cadence.

Interesting also to see how even on more neutral terrain there seem to be many short little risers that conventional gearing force you to muscle your way up. I have quickly become spoiled at having friendly gears and my ego has no problem in using mini-gears to scoot over these.

Note that speed/watts are not compromised with the CCs – legs are just a lot happier doing the same speed with livelier cadence. If anything, watts will improve with your greater efficiency, and as I experienced later in the ride.

The only thing one has to get used to with the CCs is when dropping from big chainring to small, you need to shift down in the back by 2 or 3 cogs. The reason for this is that the delta from big chainring to small is 16 teeth (50 – 34), where standard cranks delta is 13 or 14 teeth (52-53/39). Not a big deal, you just double-click on the rear cassette. You can get CCs with a 36 tooth small ring, but I think in most cases the wider range offered with the 34 ring is preferable.

Compact Cranks 5/5/06

I just recently installed compact cranks and tested them out this past weekend. For those unfamiliar, CCs are cranks whose bolt pattern will allow smaller than conventional chainrings. Standard cranks can only accept chain-rings of 52 and 38, though 52/39 is the standard. Where previously I rode with 52/39, I have now installed 50/34.

I was prompted to make this switch where my power meter clearly illustrates that I am better off spinning an easy gear than muscling a larger gear. I live in a very hilly area, and while I have always been able to climb anything with a 12/23 cogset, the Powertap consistently demonstrated that on a steady grade I could generate the same watts with an easier gear and higher cadence, and with much less grind on the legs. Where there are many climbs here that have nasty grades, such as the 18% grade up to my house, many times I had no choice but to grind up at 50-60 cadence.

My first baby step towards CCs was to install a 25 cog in the back, which was definitely an improvement, but which still left me over-geared on many of my immediate surroundings. The standard ride out my door and up the coast on Highway 1 begins with a 10min climb and average 5% grade. A switchback descent to the coast and you enjoy a 1 mile flat before you encounter a 1mile climb at 8% average grade. For me to climb this segment with an average cadence of 65, I must generate 342 watts….welcome compact cranks.

Initial sensations are as I expected; getting up hills is much easier (with no speed compromise; watts = watts) yet the legs don’t get mashed. 50/12 gives me plenty of top-end—-really, how often do you spin out a 52/12 for more than but a moment? In any case, one can always switch the cogs in the back to include an 11, and you will still have easier gears at the low end.

Very excited about the terrain I can cover and do so with nice pedaling sensations. Looking forward to finishing some longer epic style rides coming back up and over Tam, a mountain just outside my door whose various climbs can be as long as an hour and with considerable grade. Heck, even my standard routes have plenty of pitches where one typically has to grind up and over, and where the legs get mashed. Looking forward to riding many of these same routes and just spinning along.


Who should get CCs?

It is amazing to me that the bike industry did not provide these leg-saving gearing options long, long ago. In my opinion, the average rider should have CCs by default, and certainly, almost anyone that lives in the Bay Area should have them too. I do think you will see CCs become increasingly standard as more riders realize how much more efficient they are with more practical gearing. People that live in very flat areas can likely do without, but if your race schedule includes events like IM Wisconsin, IM USA, IM Canada, or cycling events like the Death Ride, then CCs are a great investment. There are a variety of makers of CCs, but the best value seems to be Shimano (price, weight, stiffness) and that is what I have installed. FSA is another maker, and marginally lighter, but I think about $200 more expensive.

As you are out riding along, observe how many times you are forced to drop cadence below 70 to get up and over hills, and how hard you are working at these less than optimal cadences. Another thing to observe might be on a steady grade, to pedal in two distinct gears (easier/harder—try 2 gears apart) but at the same road speed. Observe which cadence feels easier for the same speed. Chances are the livelier cadence (easier gear) will feel much more comfortable than the grind it out lower cadence.

What ended up convincing me of the utility of CCs was observing my watts/cadence as measured by my Powertap, and seeing how much easier it was to opt for easier gears for the same speed.

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