I am wondering what your opinions are on the following cranksets. I am in the works of getting a new P2C built up and have a choice of going with compact v.s. standard crank. I live in montana and do have several hilly areas and my main race this year will be Ironman CDA. what would you recommend for the crankset and the gearing?
Thanks,
Mike
You can sorta’ split the difference with FSA. Their new K-force light crank (really nice BTW) is a 110 BCD (compact) but they have a 52/38 set (normal are 53/39) which is just a tick lower. Couple that with a 12-27 rear, and that should be good for any tri short of Silverman or Lanzarote! The beauty is, you can still put on a std 50/34 set of compacts since it is 110 BCD without getting a new crank! The K-force light also comes with FSA’s nice ceramic bottom bracket as well. Will also save about a 1/2 lb off most other cranks. A little pricey though, but cheaper in the long run if you want to try both.
I guess I should have been more detailed in which cranksets I am looking at. The two in question are the FSA SL-K MegaExo Carbon Crankset 53/39T and the FSA SL-K Compact MegaExo Carbon Crankset 50/34T. I would absolutely love to go with the new k force light, but I also love my wife and think that would be a big battle to overcome.
Most on this forum underatand that dilemma well 
In that case, I would go with neither of those. The std. FSA SLK cranks have lots of associated problems (left arm loosening, etc.) and only “look” cool. If you want to go compact, I’d get an Ultegra compact or similar then. Not quite as cool looking, but a better crankset for the same money.
Thanks for the information, I as not aware of any issues. Now just the dilemma of going with compact v.s. standard. Do you have any advise on whether to go with a 50/34 with a 11-23 or a 53/39 and a 12-25 for CDA?
Can’t comment directly since I’ve never done IMCDA. Also, it depends upon how strong a rider you are, etc. Compacts are certainly getting more popular, especially if you more of a spinner vs. a masher, and may make sense for a long IM tri to save the legs for the marathon. Having said that, even at IMLP (which is certainly hillier than CDA), I used a 53/39 on 12-25. I personally don’t think a compact is necessary for any IM course except perhaps Silverman or Lanzarate. I now run a 52/38 and a 12-26 or 27 rear and that gets me up anything, even mountainous terrain (road bike).
second what rroof said, lots of problems with the FSA, have personal experience with failure twice
34x25 is a lot of gear all depends on how strong you are and how long and steep the mountains are. If you are going to ride 30km climb with 8% average grades it might not be a bad idea! I watched the zoncolan stage yesterday and the commentator mentioned some pros were riding 34x29! So its all relative
Yes, compacts are getting more popular for sure. I am kind of in between a masher and a spinner, and hope to average around 20 MPH. I have never needed a compact before but thought it would be nice on a few of those no so good days. I will probably just stick with the good old 53-39 that I am used to. Do you know if I would benefit much by going to a carbon crankset?
Not really - looks only. Might save some weight with the higher end units which helps a little (or a lot if you are a card carrying member of the weight weenies site)
I’m a fan of compact cranks.
50x11 is a bigger gear than 53x12 and 34x23 is a smaller gear than 39x25. I believe that says it all if you’re comparing 50/34 with 11-23 against 53/39 with 12-25.
There is also an article about compacts in the tech center:
http://www.slowtwitch.com/mainheadings/techctr/gearing.html
Joe
That is true about being a wider span of gears wth the 11-23. I however never seem to use the top end or the bottom end, I seem to stay 1 away. But if I needed to climb a steeper hill I could still use my 12-27 and now I am touch smaller with the 39x27
You might look for an original FSA K-Force compact. They can be found for $350 or less. No ceramic bottom bracket, but youget the 50x34 and can still buy the 52x38 if you want. I’m using the latter with an 11-23 cassette on my road bike.
I will check that option out, thanks
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I have compacts on my rain bike and dry bike. I need the 34-25 for climbing. That said, the other thing you want to think about is cross chaining. At around 20mph and a 90ish cadence, you’ll find yourself cross chained quite often. This means around 34-14 or 50-21. Depending on whether you’re going up or down, you have to be thinking ahead a bit.
I’ve gotten used to the issue over the last 4 years but it can be annoying.
You don’t tell us whether this is on a road or tri bike, what gearing you use now, what other uses you’ll make of the bike, etc.
Unless you think you need low gearing on a regular basis, I’d try to stick with regular gearing. However, as some have pointed out, a compact gives you all the options since you can buy chainrings from 34 to at least 53. So, if you buy a compact and don’t like it, you can later install a 53-39 for a fairly small price penalty. If you do go compact, you might try a 36 as your low gear.
At 57, I use compacts on everything except my TT bike. They work well for me even though I can still climb almost any hill around here with a 39/25 or 26. A 34/23 is slightly lower than a 39/26 while a 34/25 is lower than a 39/27 and almost the same as a 39/29. 50/11 is slightly higher than 53/12. Cross chaining can be an issue at some speeds, although if you’re fast enough you’ll be above those speeds. Why do I still have regular on my TT bike? It’s basically a race only bike, not the one I use for JRA. Because it’s a race bike, I ride it faster than I would a training ride. It’s on a P2SL that doesn’t seem to have a low enough derailleur hanger to support a compact. Lastly, my SRM was regular. I actually use it with a 50-38 and an 11-23. I might switch to 12-23, 11-25 or 12-25 (with a 52), depending on the course. The CDA profile looks really odd - it looks to be filled with choppy, relatively small hills and no really big climbs. You may end up out of the saddle and powering over some of those rather than staying aero to spin or grind.
I’m not a fan of FSA carbon cranks because of the mounting method. I had an FSA SRM and sold it at a big loss because I was fed up carrying an 8 mm allen key and having to use it most rides. I understand that others have not had any problem with this at all, but would stick with DA or Ultegra if I were using Shimano.
I am sorry, I totally forgot to tell what bike it is going to be on. I am getting a new tri bike (P2C) and it will be used for pretty much all my races. I have a trek road bike that I do most of my hilly rides on and it currently has a triple 30x42x52 with a 12-25 casette. I however do not go into the triple ring and shouuld just change out the crankset. My curreny tri bike has a 53x39 with a 12-27 and have not had to much problems going up any hills, and we have some pretty good ones around our place 8% to 11%. These hills are not to long but enough to test a person when they come one after another. The longest hill I usually ride averages 5% and is about 4 miles long.
It sounds like you’ve answered your own question. If a 53/39 works on your current bike with a 12-27, why switch?
Carbon is lighter, compact is lighter, and 11-23 is lighter than 12-27. Lighter = free speed, right?
Seriously, go with what works for you. If you haven’t had issues then go with what you know. Consider riders like Thompson or Cipollini who ride good bikes but are not cutting edge. They choose familiarity, reliability, and personal preference over marketing and looks.