IMMT Gearing Recommendations

Clark Mitchell

I've looked around and I don't see any other threads on this topic, so I'm just starting one.  I'm unsure about gearing for IMMT.  I'm ~3.65 W/KG.  Do you think I can get away with a standard 53/39 up front or should I switch up to a 50/34?  I have a 50/34 available, I'm just not looking forward to taking the time to swap it out. 

I was planning to switch to the 50/34 until I did my race rehearsal, which i did on the trainer using the course file to mimic the course elevation.  I was fine with the 53/39 during the rehearsal, but I'm just not sure how accurately the trainer represents the steeper grades.  I've read that there are a few short sections at 12%, which for me would point to the 50/34.

Thoughts?  Anyone able to share specific on-course experience?

Thanks in advance for the input!

John Withrow

I did that race in 2014 and was in the best bike shape of my life...   My W/Kg were slightly higher than that, but not by a lot.  I used the equivalent of a mid-compact (52/36) and either an 11-27 or an 11-28 and was very happy to have the extra gears.   You are strong enough and would certainly survive with the standard (especially if you went with an 11-28), but the biggest hills on that course come in the last 10 miles of each loop up towards Lac Superieur... So you'll be climbing at the end of your long ride exactly when your legs are hurting the most...

It only takes like 5 minutes to swap out a crank...   But you might have to shorten your chain which for me is a "LBS mechanic" trip.  If it were me, I'd still swap to the 50/34...

scott dinhofer

@Clark Mitchell - I've biked with you and climbed hills with you, you are a beast!, that said, this is not a roadie ride... the ideal would be what JW described above, but since you have the 50/34, i'd do the swap also, and I've done MT as well.. 

Clark Mitchell

Thanks guys I appreciate the input. I'll swap out to compact and I'm going to need a new chain for race day regardless, so that's no big deal. Thanks again!