Trek has a archive that goes back that far. https://www.trekbikes.com/us/en_US/c...uel-8/p/19642/

That says the bike came with a Shimano SLX crank. Which is a 2 piece crank and can use a threaded bb or a press fit bb. So maybe a BB-MT801 will fit.

If you got this bike used, then a previous owner might have put a different crank in it. So looking on the backside of the crank arm and telling use the part number will tell you/us what crank is actually in the bike currently. A Shimano crank will usually have the model number around the pedal hole on the back side. Crank length too. Not that it matters for this. Knowing that the crank is what the specs say it's supposed to be will help.

The BB info a particular Shimano crank uses can be found at http://si.shimano.com/#/

Look in the blue bar near the top and select technical documents. Then knowing that it's older 2011 bike, go to the archives for 2011,

https://productinfo.shimano.com/pdfs...CIFICATION.pdf


Which back then was a SM-BB70. But the BB-MT801 I think meets the same specs. You should double check that though. You need to learn how to research!