First of all, let me be the first to say: KICK. ASS. To even think about this is a pretty massive undertaking. Given the short time frame and the X-TREME () fashion in which you're attempting it, I think you will need to make a pretty significant adjustment.

Secondly, I'm told Boston-Montreal is pretty horrible. I know that southern Quebec is like a barren pancake but there's a TON of climbing in southern Vermont. Unfortunately, while Middlebury and Ludlow sit about 2,000 feet above sea level, Montreal is only 500 and Boston is 0, which means you have to climb only slightly less on the Montreal-Boston direction. Here's an elevation profile: http://www.geocities.com/b-m-b/route.html#Profile . Terrible.

Speaking of BMB, talk to people who ride brevets. They'll give you good advice, I'm sure. How many days do you have to complete this? At least this should be a less arduous event than BMB (which is recommended for those with triples only!). This is "only" 425 miles in 102 hours which is a lot nicer than the 750 of BMB in 90.

My own advice: have a few gears to pick from. Don't be afraid to do some in-field service. Maybe for the Quebec leg of the journey you have a set of relatively closely spaced gears on a flip-flop for the flats or perhaps even a nice high (relatively speaking) road gear plus a light climbing gear. That should take you to Middlebury.

Given the wicked climbing and descending from Middlebury to Ludlow, I would probably do a wholesale gear change. I think maybe a couple of low climbing gears or a climbing gear and a freewheel descending gear. 20 miles of descending would suck on a low climbing gear. If you are determined to do it fixed all the way, then just have one very low climber and a higher descending gear that you can switch to at peak elevation.

Then you're into rolling New England. That's a crap shoot. Hit something in the high-60s to low-70s. I did a metric (not long compared to what you've got coming) at 77" and one at 74" and both were a bit taller than I would have liked. I've got one coming up next weekend on 61" which I think will be much lower than necessary. But you can pretty much always spin, you can't always mash. The climbing and descending are generally not consistent enough in one direction to make it worth flipping a wheel.

As for training, they say to increase your mileage about 10% each week. Of course that's when you're looking at a one-day event. Here your individual days aren't so terrible (a century? that's not so bad.) but it's four days in a row. I've heard you typically want to be able to ride 2/3 to 3/4 of your target mileage before the event. So taking that approach, maybe you want to do a double century or two-to-three days of consectutive centuries.

Food-wise, STAY HYDRATED. That's so critical. It's easy to be under-hydrated and not notice until it's too late. Starting as much as a day before each major ride you should start drinking as much water as you can stand. Stop maybe 30 minutes before you start so that you aren't terribly bloated. Be sure to take the very last pee break you can. Otherwise you'll get about 10 minutes into the ride and realize you have to go. If you go with an off-the-shelf sports drink like Gatorade, mix it about 1:1 with water. This is an isotonic solution: it's salinity matches your blood's (more or less) and makes it very easy to absorb. The ghetto fabulous version is a 30%-50% OJ solution (thanks, MC). Throughout the ride continue to drink water before you're thirsty. The day before and day of, avoid alcohol which will dehydrate, cause your muscles to be sluggish, and put a strain on your liver and kidneys which need to be in good shape to process all the water and blood you'll be moving.

Starchy foods are great in the few days leading up to your event. This is carbo-loading. It can raise the amount of glycogen stored in your muscles by something like 50%. During recovery (including while training) have some protein. If you're a vegetarian/vegan, beans and nuts are a good source of this. The day of your event, eat a light breakfast staying clear of fats and proteins. Some starch and lots of sugar is good. Fruit sugars are particularly good. On your ride each fruits, starch, and some protein. GORP: good ol' raisins and peanuts is still favored by many.

Of course everything mentioned about proper riding gear is spot on. This is no place for proving a point about how core you are riding out there in shorts and a t-shirt with boxers underneath. Padded shorts are the most important (and be sure nothing comes between your ass and your chamois or I'll sic the underwear nazi on you). Fortunately, your training rides should sort out your gear selection for you.

Good luck. I think it's quite doable, but it will require careful planning with regards to the terrain. Be sure to talk to others who have ridden this or randonneurs in general. I'm sure they have lots of really good advice to pass on.