I’m looking for some advice on how best to configure my ride for IMMT (140.6) this august which will be my first full IM.
Context:
I am a bigger triathlete (read: fat). 5’5" and 230…maybe 215 by race day. I have been doing tri’s for about 8 years and have done one HIM each year for the past five…times getting better and better…just about 7 hours. I’m a MOP swimmer, a decent cyclist, and a weak runner.
Cycling FTP is 200.
Uncertainty:
I am unsure which bike to use in IMMT this year: my road bike or my tri bike. My tri rig is faster no doubt, but for climbing…i’m not sure the down hill gains would be worth the time lost on the up hills. I’ve done a few test runs on local hills (rides were just about 40 miles and just about the same feet per mile climbing on par with race) and so far the conclusions are:
Heart rate is lower on Road bike (duh…position is less aggressive…lungs are more open…more quads used)
Power is just about the same on both bikes with power on road bike being 2-3 watts more
RPE (rate of perceived exertion) is that my toosh is more comfy on road bike and I generally feel more powerful on road (duh…compact cranks are easier on legs on hills)
It should also be noted that while I am a capable bike handler, the chances of zooming down the hills at IMMT in the aero bars at 40+ mph is unlikely. I’d move to the bullhorns.
Bike Options:
Felt IA 10 w/ SRAM etap - 53x11 & 11x27 (standard)
Felt Z 85 w/ Shimano 105 - 50x34 & 11x28 (compact)
Wheel Options (i own all five):
Planet X 50mm carbon clinchers front/back
Flo 90mm carbon clinchers front/back
Flo Disc
At this point I’m kinda leaning toward road bike…maybe with the 90/90 combo or 90/disc combo. Your thoughts?
Ignoring the actual time differences, I’d say it depends on your goals. Going for a specific aggressive time goal? Tri bike. Prioritize comfort and willingly sacricice some time to likely feel fresher in T2? Road. As you say you’re a weaker runner, maybe that fresh feeling in T2 will be worth more in the end if you can run better. With a deep front and disc wheel on the road bike you would get good aero gains there and doubt you’d be overly sluggish on the downhills if you’re down in the drops.
Here is some advice from a MOPper who just practiced the whole bike course last week:
There are 8 or 9 locations on the “up” side of Duplessis where you will need your easiest gears, and 2 locations on the “down” side where you will also need your easiest gears.
I had a 50-34 and 11-28 combo. Anything less, and I would not be comfortable (i.e. have to get out of the saddle, and use too many watts). I am lighter than you with a higher FTP W/kg. You may have to walk some of the hills.
From your opening statements, I suspect you would prefer to sit upright on the Montee-Ryan section as it is rolling with some fast descents, so perhaps the road bike.
However, the entire hwy 117 section of the course (with the exception of the Conception Climb), is relatively flat, and is best suited for a tri-bike if you can hold an aero-position.
It can be windy, a rear disc is not a problem, but a very deep front wheel can be tricky on 117 especially the Conception downhill.
Regardless of your plan - make sure your shifting works well through your whole cassette, and your chain rings; there are some spots where you need to drop a bunch of gears quickly and also spots where you add a bunch of gears quickly.
As others have said, it’s more about gearing than the bike you ride. At your weight and FTP there are places you are going to have trouble staying upright without going over FTP. Get as much gearing as possible first. A compact crank and the biggest cassette you can fit would probably be a minimum.
A tri bike is almost certainly going to be faster. If you want to ride your road bike because it’s more comfortable our more fun to ride, then it becomes a personal preference decision.
Totally agree with others that the gearing is much more important that which bike you use. If you anticipate being on the course for a long period, I’d probably lean more towards comfort.
I’m a MOP on the bike. I did the race last year with a compact and 11-32. I used every gear. You’ll need at least a 28 in the rear. I would ride with a disc, no reason not to. I rode with a wheelbuilder disc cover.
I did the first IMMT in 2012 (finished just under 14 hours, so definitely not scaring any of the leaders). Worried about the hills, I raced on my road bike. No complaints or regrets, but if given the chance for a do-over, I would choose the tri bike. There are some hills on the course (although I think the current course is slightly different than 2012), but nothing that extreme. If you’re comfortable riding aero for 112 miles, I think a tri bike would be fine.
I would go tri bike all the way, you will want it for the long section on 117. I would also ride it every ride from now until race day.
As Jason mentioned see about switching the compact to the tri bike. You may not be able to get a bigger cassette than the 28 without a new rear derailleur. You will likely still need to dig deep up to your FTP on some of the short steep stuff on Duplessis with a 34x28 but they are not long, the second time up that will be tough. Keep working on getting the Kg part of the W/Kg down as long as you don’t underfuel your workouts.
Maybe someone with a similar W/Kg FTP could chime in, I think that would be helpful. bx3 indicated that he would not be comfortable with less than 34x28 but is lighter with higher FTP.
Thanks for all of the feedback so far. And yes, I’m down 9 lbs to help that w/kg ratio
Unfortunately I cannot swap cranksets. One is a shimano, the other sram and the crankset diameters are incompatible.
I’m going to hit some hills this weekend on the road bike, same route I rode two weeks ago on tri bike, and do some data analysis/comparison. As of today, i’m leaning toward roadie for comfort and better gearing.
I did IMMT in 2016, go with a TT bike. The only hills are on the last 10k of each turnaround, some are tough but very short climbs. I used a 11-28 and it worked fine for me. Just be prepared to come off the saddle on the tougher climbs. The rest of the course is pretty easy and you will benefit from a TT bike and save your legs for the run.
For $100 bucks you could ebay a compact crank for your tri bike. You could even sell it when you’re done and not be out much money if you think you won’t need it again.
If you are not going to use tri bike on this course I would question why have a tri bike. Nothing wrong with that.
hehe Ironman Atlantic City 70.3 - 500ft of climbing total in 56 miles.
But I hear you…i’m just worried about the climbing on this course. My TT position is much more aggressive than my road bike and i’m also not sure I can maintain that position for 112 miles without severe neck and back issues.
Have you considered clip on aero bars for your road bike? I did this for IMLP this year and was really glad I had my drops for the Keene descent in the rain with cross winds and then I was really glad I had the aero bars for the flatter sections, which from what I understand are fewer than Tremblant.
I have thought about it. At one point I did have them on my roadie until I got my IA 10…then I just used that for all Tri’s. But most of the tri’s I do are flat and this is my first full IM. I’ll look into the option again.
Thanks for all of the feedback and advice. I’ve decided to roll with the road bike.
You can always go back a second time and use the tri bike – which I bet you might. As a big guy myself who completed IMMT, you’re giving up a lot of free speed and distance with many of the descents. The beauty of Tremblant Bike course is most of the descents on the front half out of the village, and ALL of the descents on the highway are long and straight with no turns to take away your speed!! There are long, straight sections of descent where you can just cruise in the aerobars at 20+ mph while soft-pedaling. Just some food for thought.
Although you will definitely be happy you have the road bike on your second trip up Duplessis around mile 100!! Although it’s important to note Duplessis is the shortest section…
50/disc if you can only take one wheelset. If you can take one more wheel I’d go with the 90 front then decide on which front wheel to chose once the weather report is out. No reason not to go disc in the back. Through the disc on the back during your training rides to give you some confidence that it’s the right choise. You’ll be giving up some time using the roadie and can get some of that back with the disc.
