I am currently riding 53/39 in the front and 12-25 in the back.
As I am signed for IMMT, I am beginning to think about changing my gearing to better suit the hills I will encounter next summer.
Would you consider a compact crank or just change the cassette? Thanks for your thoughts.
I rode a STD crank and a 11-27 cassette at both Placid and IMC. I ride around Tremblant on my tri bike w/ a 27 rear, or my road bike w/ compact crank and a 25.
I would change the cassette to a 27…
It really depends on what type of rider you are (ie. do you spin or mash). It also depends on how strong of a cyclist you are.
I am more of a spinner… So 12-27?
Unless you ride at the elite AG level or higher, you’ll get much more use out of a compact crank (say 50/34). On a course like LP, you don’t really have to worry about running out of gears at the high end. The downhills are all reasonably steep and fast, so you’ll be freewheeling them anyhow. On the uphills, a 34/25 ratio will get nearly anyone over the steepest ascents, but you can always opt for a 12-27 cassette and buy yourself that 34/27 insurance.
Don’t know much about the MT course, but I’ve ridden all over LP with riders of various ability. The compact crank was always the gearing of choice (or at least the front part of it).
Do this: http://road.cc/content/news/36163-giro-tech-contador-goes-apex
I did and it works wonderfully and can be a cheaper swap than some compact cranks.
I have been considering that option. In the past I would swap out my 53/39 crank for a 50/36 crank when having to deal with big hills. My FD hanger on my bike does not go low enough to allow me to use a 50/34 crank and even with a 50/36 I need to switch my FD from my usual DA to a Red (which I do not like as much). It should be easier to switch to the Apex RD. The only thing that concerns me is the big gaps in the gearing with a 12/32 cassette or God forbid a 12/36 cassette.
For what is worth, I’m doing IMLP this coming summer as well and have a 39/53 up front and will be swapping my 11-25 cassette out for an 11-28. Wanted that extra low end gear or two just in case.
Thanks for sharing all. One last piece to share . . . found this online and found it interesting reading:
http://whynottri.wordpress.com/2008/05/28/going-compact-standard-vs-compact-cranks/
I noticed the larger jumps early on but now I’m used to it and it isn’t a bother.
If you are 3.5-3.8W per kilo guy compact crank with 12-27 for Tremblent and LP…could probably be fine with a 25.
If you are over 4W per kilo guy then compact with 12-25
If you are around 4.2W per kilo guy then go with the standard crank and 12-25
Gearing for IM really is about mating the drivetrain with the available watts per kilo.
I’m doing IMMT too. I’ll be running a 50/34 and 11/28.
FWIW I’ll be 60 by race day.
I would consider myself a better-than-average cyclist that loves climbing. I’m a spinner.
12-25 with 53/39 was NOT enough for Lake Placid. I really wish I had a 27 in the back. It was a rude awakening.
I found myself grinding up the hills. Going compact might happen this year, but first I want to take a look at the actually ratio’s to see if there is a big enough difference to justify such a radical change (meaning pricey).
I’m doing IMMT too - at the very least going with a 27 on the back. If anyone has a link to a gear ratio chart I would appreciate it.
Edit: oh and I’ll throw in that I did all my training with a 12-23 & 53/39. I switched to 12-25 for the race. Admitedly, I probably went out too hard on the first lap which contributes to my regret 
haha!
I would consider myself a better-than-average cyclist that loves climbing. I’m a spinner.
12-25 with 53/39 was NOT enough for Lake Placid. I really wish I had a 27 in the back. It was a rude awakening.
I found myself grinding up the hills. Going compact might happen this year, but first I want to take a look at the actually ratio’s to see if there is a big enough difference to justify such a radical change (meaning pricey).
I’m doing IMMT too - at the very least going with a 27 on the back. If anyone has a link to a gear ratio chart I would appreciate it.
Edit: oh and I’ll throw in that I did all my training with a 12-23 & 53/39. I switched to 12-25 for the race. Admitedly, I probably went out too hard on the first lap which contributes to my regret haha!
What is your weight and do you know your watts per kg? If you can’t tell us your watts per kilo, do you know your 10K run split and your weight…that’s probably a decent enough proxy for watts per kilo to know what type of gearing you’ll get away with.
What was your bike split at IMLP and run split?
If you can’t tell us your watts per kilo, do you know your 10K run split and your weight…that’s probably a decent enough proxy for watts per kilo to know what type of gearing you’ll get away with.
How can I calculate that?? I’m 67-68kg and run a ~38min 10k
Rchung has a method that coverts m/s running to watts per kilo, but assuming your biking ability is similar to your running ability, you likely need a 34-25, although you’ll probably get away with a 39x27.
Dev- Question for you.
FYI We met at the Red Roof in Plymouth before Mooseman in 2010.
I am doing IMMT for my first IM. 11 halfs but never a full. I bought 50/34 compact cranks (Quarq) and will be swapping out my old 53/39 next week. Since they are not on the bike yet I don’t have my FTP number or watts/kg yet. For reference, I ran a 43 min 10K a few months ago at about 70 kg when I was in decent running shape but not great. Ran a 19:5x 5K last September when I was closer to 68K and in about the best running shape I can get to these days, plus or minus 20 seconds. I am probably a little better cyclist than runner; 89th percentile on the bike vs. 87th percentile on the run overall last year at Timberman, usual a bigger gap than that but still pretty close between the two disciplines though.
I am trying to decide on my gearing for Tremblant so that when I set up the new cranks the chain length is correct.
I have been running a 53/39 with a 13-26 in the recent past. Prior to the last few years I was running 12-23 for races like Timberman and Mooseman (old course) 70.3s. When I changed from the 12-23 the deciding factor between a 12-25 and the 13-26 was having the 18 in the 13-26. I really like having this gear with both chainrings. Maybe that will change with the 50/34.
Is the 34x26 enough or would you suggest 12-27? At the other end of the spectrum at 100 RPM I would be going 30.1 mph with the 50x13 vs. 32.63 with the 50x12. I never felt I really needed more gear in a tri than the 53x13 which was 31.92 at 100 rpm.
I can try the 13-26 to start since I have it already but I won’t be able to simulate IM race conditions until race day!
Thanks for you advice.
I am currently riding 53/39 in the front and 12-25 in the back.
As I am signed for IMMT, I am beginning to think about changing my gearing to better suit the hills I will encounter next summer.
Would you consider a compact crank or just change the cassette? Thanks for your thoughts.
I have one setup, a 50/34 11/28. Flat or hilly, I am ready for anything.
Dev- Question for you.
FYI We met at the Red Roof in Plymouth before Mooseman in 2010.
I am doing IMMT for my first IM. 11 halfs but never a full. I bought 50/34 compact cranks (Quarq) and will be swapping out my old 53/39 next week. Since they are not on the bike yet I don’t have my FTP number or watts/kg yet. For reference, I ran a 43 min 10K a few months ago at about 70 kg when I was in decent running shape but not great. Ran a 19:5x 5K last September when I was closer to 68K and in about the best running shape I can get to these days, plus or minus 20 seconds. I am probably a little better cyclist than runner; 89th percentile on the bike vs. 87th percentile on the run overall last year at Timberman, usual a bigger gap than that but still pretty close between the two disciplines though.
I am trying to decide on my gearing for Tremblant so that when I set up the new cranks the chain length is correct.
I have been running a 53/39 with a 13-26 in the recent past. Prior to the last few years I was running 12-23 for races like Timberman and Mooseman (old course) 70.3s. When I changed from the 12-23 the deciding factor between a 12-25 and the 13-26 was having the 18 in the 13-26. I really like having this gear with both chainrings. Maybe that will change with the 50/34.
Is the 34x26 enough or would you suggest 12-27? At the other end of the spectrum at 100 RPM I would be going 30.1 mph with the 50x13 vs. 32.63 with the 50x12. I never felt I really needed more gear in a tri than the 53x13 which was 31.92 at 100 rpm.
I can try the 13-26 to start since I have it already but I won’t be able to simulate IM race conditions until race day!
Thanks for you advice.
I think I might have to give the 13-26 a shot, the chain wrap with the 12-227 is 31 and it seems that my short cage Chrous 10s is rated to 27 but many say you can get 1 or 2 more teeth without a problem. The 13-26 with the 50/34 has a chain wrap of 29 teeth. Anything bigger will likely require a new rear derailleur.
Anyone use a 50x13 as a top gear?