This is a North American thing. The three Euro IMs that I've done, none had special needs bike bags. The Europeans seem to do just fine without a bike special needs bag.

Don't get me wrong. If they offer it, definitely use it ... even if it's just used to contain spare tubes, back up nutrition, and etc, but one can perform just fine without a special needs bag or stopping for one.

I KQ'd and do not use a special needs bag for the following reasons.
1. Adapt to nutrition on the course. Maybe I'm lucky, maybe I plan better and adapt to it, and maybe it's because I travel to races where the nutrition varies more than it does on NA courses, but using what is on course and knowing it works for you is very helpful. In addition, if you KQ, you are at the front, and certainly won't have any issues with aid stations running out or being overcrowded. (well, overcrowded perhaps on a looped courses.) Finally, having raced Mont Tremblant at the 70.3 WCs last year, it was damn cold on the course! I guess it should be warmer for the IMMT, but when it's cold like that, my fluid needs are less. So that is another important aspect of nutrition to plan for....if you are not drinking as much calorie-intense fluids, you need to have a backup in your back pockets to eat as you go. I train in conditions regularly over 35 degrees, and when it is under 25, I just don't sweat much and I get a sloshy feeling in my stomach pretty quickly if I continue to drink at the rate I would for warmer temps. Make sure you think this through. But still, carrying bars on the bike is quite easy and still no need for special needs in my opinion.

2. Spare CO2 etc? I guess if you really need a double layer of insurance this can make sense. But I'm assuming you are carrying repair kit on the bike. For me it's not worth the bother of collecting it after. If I needed to use two flat kits, I'm guessing my shot at KQ would be out the window....so just enjoy the race after getting help with the second flat.

3. For those who are nutrition specific, if you use powder, just pick up water on the course. It has to be quicker then potentially waiting for a special needs bag. People are posting it only takes 1 minute. I got my KQ slot by finishing 2 minutes in front of the third place guy who did not get a ticket to Kona. This is a huge amount of time given the potential margin of success/failure on KQ. Hilarious to spend so much money on aero this and that to hand back all the marginal gains waiting for a bag of stuff that you could have carried.

4. On course nutrition is a part of the race. Other than that, however, I do not want to put the fate of my race in the hands of anyone else. Any number of things could happen to delay getting the bag, fishing out what you want, and carrying on again. There is also the psychological element...if you don't get the bag you were counting on, it will affect your mind, even if you can adapt to live off the course. Reduce what you need. Train for being sustainable on that bare minimum and put your KQ destiny in your own hands. I had a long talk with the 3rd and 4th place finishers who missed Kona by 2 minutes and 3 minutes respectively. Not a happy place as they listed all the ways they lost time for no advantage.

5. Special needs is just that...special. Something out of the ordinary happened on the race. One time I put an encouraging note from my family in the bag. I knew what it said, but I still picked it up (on the run, loose far less time in my opinion!) just to have that little pep talk at a low point in my race. Worked far better than any nutrition would have!

Good luck with IMMT and figuring out what you need to make it happen! :)

How big is your bottle? How can you load 750cal into it?

I've never used special needs. I start with what I prefer and then live off the course, and the main reason for that is I got some good advice a long time ago that one thing you need to make sure of is to have a backup plan. What happens if you lose a bottle of nutrition--from a pothole or a cap that breaks or drop it or whatever. It would be a shame to have a lost bottle ruin your entire day, but if you can use what's on the course, all you need to do is make it to the next aid station.

I've never used special needs. I start with what I prefer and then live off the course, and the main reason for that is I got some good advice a long time ago that one thing you need to make sure of is to have a backup plan. What happens if you lose a bottle of nutrition--from a pothole or a cap that breaks or drop it or whatever. It would be a shame to have a lost bottle ruin your entire day, but if you can use what's on the course, all you need to do is make it to the next aid station.

I KQ'd and do not use a special needs bag for the following reasons.
1. Adapt to nutrition on the course. Maybe I'm lucky, maybe I plan better and adapt to it, and maybe it's because I travel to races where the nutrition varies more than it does on NA courses, but using what is on course and knowing it works for you is very helpful. In addition, if you KQ, you are at the front, and certainly won't have any issues with aid stations running out or being overcrowded. (well, overcrowded perhaps on a looped courses.) Finally, having raced Mont Tremblant at the 70.3 WCs last year, it was damn cold on the course! I guess it should be warmer for the IMMT, but when it's cold like that, my fluid needs are less. So that is another important aspect of nutrition to plan for....if you are not drinking as much calorie-intense fluids, you need to have a backup in your back pockets to eat as you go. I train in conditions regularly over 35 degrees, and when it is under 25, I just don't sweat much and I get a sloshy feeling in my stomach pretty quickly if I continue to drink at the rate I would for warmer temps. Make sure you think this through. But still, carrying bars on the bike is quite easy and still no need for special needs in my opinion.

2. Spare CO2 etc? I guess if you really need a double layer of insurance this can make sense. But I'm assuming you are carrying repair kit on the bike. For me it's not worth the bother of collecting it after. If I needed to use two flat kits, I'm guessing my shot at KQ would be out the window....so just enjoy the race after getting help with the second flat.

3. For those who are nutrition specific, if you use powder, just pick up water on the course. It has to be quicker then potentially waiting for a special needs bag. People are posting it only takes 1 minute. I got my KQ slot by finishing 2 minutes in front of the third place guy who did not get a ticket to Kona. This is a huge amount of time given the potential margin of success/failure on KQ. Hilarious to spend so much money on aero this and that to hand back all the marginal gains waiting for a bag of stuff that you could have carried.

4. On course nutrition is a part of the race. Other than that, however, I do not want to put the fate of my race in the hands of anyone else. Any number of things could happen to delay getting the bag, fishing out what you want, and carrying on again. There is also the psychological element...if you don't get the bag you were counting on, it will affect your mind, even if you can adapt to live off the course. Reduce what you need. Train for being sustainable on that bare minimum and put your KQ destiny in your own hands. I had a long talk with the 3rd and 4th place finishers who missed Kona by 2 minutes and 3 minutes respectively. Not a happy place as they listed all the ways they lost time for no advantage.

5. Special needs is just that...special. Something out of the ordinary happened on the race. One time I put an encouraging note from my family in the bag. I knew what it said, but I still picked it up (on the run, loose far less time in my opinion!) just to have that little pep talk at a low point in my race. Worked far better than any nutrition would have!

Good luck with IMMT and figuring out what you need to make it happen! :)