I decided this year to go 11-28 for IMWI after 3 times doing it on 11-25. When I go back to IMLou, I will not be using the 11-28, I will use 11-25. I am running a 52 /36.

I would recommend an 11/28. How big are you? I'm a large mammal and there were times I wished for even more gears than that.

Well...I'll be the first.............


I bought a new Specialized Roubaix (SL4 - Expert) last year.....and it came with a 11-32 cassette. I liked it so much (and I have a long cage RD on my P2) I put one on my P2 (on my FLOs). I run it all the time, now. I raced it at Choo 70.3....and I don't feel like I'm missing any middle gears. I'm running a 50/34 on the front.

I'm 52.....193#s....FTP of 240. I'll be running this setup at IMLOU.

You don't need 11-28 for IMLou. It's a rolling course, and there is only one short but steep section (maybe 15-30 sec?) where you may need a big cog in the back.

That is interesting. On both Strava and the IM website, that climb around mile 10 looks like it is pretty rough. How much total climbing did you see over the course of the race?

are you talking about the old course, or the new course?

I haven't done the new course but from comparing my athlete guide from 2015 to the 2017 guide...it looks like they took out the biggest elevation part which was KY 1694 aka the suicide hairpin turn/out and back.

At 58kg I used a 10speed 50/34 and 11/25 when I did IM LOU in 2015 and I was comfortable with that. I definitely think with KY 1694 out of the picture at most you'd need is 11/28. All that is left is a bunch of rollers.

Edit: but I still would stick with the 11/25 personally. I'd only suggest 11/28 if you normally have issues with rollers.

Talking about the new course.

My Garmin showed about 4500 elevation gain, but most of the climbing is on the rollers, and you can carry your momentum pretty well.

Climbs at mile 10 and 22 are a bit longer (about .5 mile each) but not very steep (about 3% gradient according to my Garmin) - you don't need a 28 in the back for those.

The small kicker I referred to is somewhere around mile 30-40. It's a short little climb, but the grade kicks up unexpectedly towards the end - your cadence will be very low for a few seconds, but it will be over before you know it.

I raced it on an 11-28 and thought it was fine. I may not have used the 28 much but when I did I needed it and it made a difference when I got to the run. Running that cassette sure didn't hurt my bike split either considering I posted a very low 5hr bike split.

My wife used an 11/28 and she did just fine. She's a steady rider and told me the bike course "was not hard". It's mainly rollers with a few climbs but nothing too rough.

+1. I raced IM LOU in 2016, with 11/28. Lots of rollers. Try not to lose momentum. I don't remember encountering any hard or long climb.

One section is to watch out for is a short "farm back road" when you turn off to your left, with really sharp and small hills, and you have to slow down suddenly (sorry, I can't recall the road name). I wasn't paying attention & I dropped my chain there... and so did many other racers.

Good luck! I loved the river current assisted swim! The water was so warm in 2016, it was like jumping into a gigantic warm bathtub.

I've used an 11-25 and 12-27 there. I found I liked the 11-25 better. You definitely don't need anything with 28t.

I remember that left turn, I fishtailed there for a second because the two riders in front of me took that turn much slower than I. I did that race last year with a 50/34 crank 11-28 cassette had no problems at all (I was 190# on race day).

Here's the ride on Strava https://www.strava.com/activities/740043427

You'll see there isn't any really steep climbs just a bunch of rollers so I think with a 25 as your largest cog should be fine.

That road is Ballard School Road and it has some short steep pitches (and one short but steeper pitch on Old Sligo). I recommend 11/28. Why burn matches going up short steep pitches at a low cadence? If you end up not needing the 28 -- well congratulations -- but for the insurance of having that lower gear, you only had to pay by slightly wider spreads between gear ratios. I last did the course in 2015 @ about 19.8mph. I have ridden the new course multiple times. I weigh about 170 lb if you are less heavy -- YMMV.

One more thing -- the rollers are just rollers unless there is a big headwind (we occasionally get them in KY). You might really want that additional gear on a long day with high winds.

I am leaning toward switching it out. I figure it is better to have the extra gear and not need it, especially with my lack of experience.

Are most people getting 4500 elevation gain (rather than the 5400 stated on the IM site)?

I have done Chattanooga and Vineman with a 12/27. Would 11/28 be better for Lou?

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Janyne

Quote for truth! And it applies for most things: better to have it and not need it then to not have it and require/want it.

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Tomorrow is not promised. Increase the Peace.

I'll be riding a 11-28 with a 53/39.

It'll be my first full IM. Good luck with the race!

Good luck to you, too. This will be the first race that I count as a full IM. I did North Carolina last year, but with that 56 mile bike course, I don't count it.